Mechanics

INPUT TURBINE SPEED SENSOR CIRCUIT MALFUNCTION

1996 Honda Accord • 260,000 miles

Codes po715 came up when scanned and code po137
transmission will not go into drive in any gear but will go into reverse with a delay
AD
Avatar
Rick0415
January 28, 2012.




ENGINE CONTROLS - TESTS W/CODES - 2.2L 4-CYL -1996 Honda Accord EX
Page 1 of 1
DTCS P0137 & P0138 - REAR HEATED OXYGEN SENSOR (HO2S) SENSOR 2

Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES
engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until
radiator fan comes on. Using scan tool, check HO2S (sensor 2) output voltage with engine speed at 3000 RPM.
If voltage does not stay at.3 volt or less, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at HO2S (sensor 2) and PCM connectors.
See WIRING DIAGRAMS section. Repair as necessary. If voltage stays at.3 volt or less, turn ignition off.
3. Disconnect HO2S (sensor 2) connector. Start engine. Using scan tool, check HO2S (sensor 2) output voltage. If output voltage does not stay at.3 volt or less, replace HO2S (sensor 2).
If output voltage stays at.3 volt or less, turn ignition off. Disconnect PCM connector "D". See Fig. 4 or Fig. 19. Check for continuity between ground and HO2S (sensor 2) harness connector
terminal No. 2. If continuity exists, repair short in White/Red wire between PCM connector terminal D14 and HO2S harness connector. See WIRING DIAGRAMS section. If continuity
does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
1.
. Start
2.
4.

1/27/2012

AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 1 of 31
ARTICLE BEGINNING

APPLICATION

TRANSAXLE APPLICATION Vehicle
Accord (V6 2.7L)
Transaxle Model MPZA
CAUTION: Vehicle is equipped with a Supplemental Restraint System (SRS).
When servicing vehicle, use care to avoid accidental air bag
deployment. All SRS electrical connections and wiring harnesses
are covered with Yellow insulation. SRS-related components are
located in steering column, center console, instrument panel and
lower panel on instrument panel. DO NOT use electrical test
equipment on these circuits. It may be necessary to deactivate
SRS before servicing components. See appropriate AIR BAG DEACTIVATION PROCEDURES article in GENERAL
INFORMATION.
NOTE: Obtain radio anti-theft code from vehicle owner before disconnecting
negative battery cable. Radio anti-theft code must be re-entered into
radio once negative battery cable is reconnected. To re-enter radio anti-theft code, turn ignition and radio on. When CODE is displayed on
radio, re-enter radio anti-theft code by using radio station preset buttons.
DESCRIPTION

Automatic transaxle is electronically controlled. Transaxle shifting and torque converter lock-up are controlled by Transmission Control Module (TCM). TCM is located below instrument panel under
front lower panel on passenger's side. TCM receives information from various input devices and uses this information to control shift, linear and lock-up control solenoid valves.
The TCM contains a grade logic control system which controls transaxle shifting while vehicle is ascending or descending a slope, or reducing vehicle speed. Transaxle is equipped with shift and key
interlock systems. Shift interlock system prevents shift lever from being moved from Park unless brake pedal is depressed and accelerator pedal is in idle position. In case of a malfunction, shift lever
can be released by placing ignition key in key release slot near shift lever. Key interlock system prevents ignition key from being removed from ignition lock assembly unless shift lever is in Park.
The A/T gear position indicator on instrument panel contains lights to indicate which position A/T gear position switch on shift lever is in.
OPERATION

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 2 of 31
A/T GEAR POSITION INDICATOR

With ignition in RUN or START position, voltage is supplied to A/T gear position indicator, located on instrument panel. See Fig. 1. When shift lever is moved to designated gear position, A/T gear
position switch completes the ground circuit for A/T gear position indicator. The light on A/T gear position indicator will illuminate to indicate shift lever gear position. The A/T gear position switch is
located on driver's side of shift lever. See Fig. 2.
When headlights are turned on, voltage is applied to A/T gear position indicator dimming circuit through Red/Black wire from combination light switch. Brightness of dash lights is controlled
through Red wire from brightness controller.
GRADE LOGIC CONTROL SYSTEM

The TCM compares actual driving conditions with driving conditions memorized in the TCM, based on input signals from Vehicle Speed Sensor (VSS), Throttle Position (TP) sensor, Engine Coolant
Temperature (ECT) sensor, Barometric Pressure (BARO) sensor, brakelight switch signal and A/T gear position switch. The TCM uses these input signals to control shifting while vehicle is ascending
or descending a slope, or during deceleration.
When the TCM determines vehicle is ascending a slope with shift lever in "D4" position, TCM extends engagement of 3rd gear to prevent transaxle from frequently shifting between 3rd and 4th
gears. Shift points between 3rd and 4th gear are stored in TCM, which allows the most suitable gear selection depending on conditions.
When the TCM determines vehicle is descending a slope with shift lever in "D4" position, TCM changes upshift speed from 3rd to 4th gear when throttle is fully closed. This widens the 3rd gear
operating range from that programmed for level surface operation and, in conjunction with engine braking from torque converter lock-up, provides smooth vehicle operation. When vehicle is
decelerating on a gradual hill in 4th gear, or when applying brakes on a steep hill, the transaxle will downshift to 3rd gear. When vehicle accelerates, transaxle will upshift into 4th gear.
When vehicle decelerates from speeds greater than 30 MPH, TCM shifts transaxle from 4th gear to 2nd gear earlier than normal to reduce the number of times transaxle shifts. This allows smoother
acceleration and vehicle operation.
SHIFT & KEY INTERLOCK SYSTEMS

Shift Interlock System

Shift interlock system prevents shift lever from being moved from Park unless brake pedal is depressed and accelerator pedal is in idle position. Shift lever cannot be moved from Park if brake
and accelerator pedal are depressed at the same time. In case of a malfunction, shift lever can be released by placing ignition key in key release slot near shift lever.
Voltage is provided to shift lock solenoid when ignition is in RUN or START position. When brake pedal is depressed, brakelight switch provides voltage to TCM, provided accelerator pedal is in idle
position. With accelerator pedal in idle position, a voltage signal is delivered between Throttle

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 3 of 31
Position (TP) sensor and the TCM. The TCM then provides voltage to shift lock circuit in the interlock control unit. When A/T gear position switch is in Park, interlock control unit operates shift
lock solenoid by controlling the ground circuit. When shift lock solenoid is energized, shift lever is released and can be moved.
The A/T gear position switch and shift lock solenoid are located on driver's side of shift lever. See Fig. 2. Interlock control unit is located behind driver's side of instrument panel and contains an 8-pin
harness connector. See Fig. 2.
Key Interlock System

Key interlock system prevents ignition key from being removed from ignition lock assembly unless shift lever is in Park. Voltage is provided to key interlock switch from fuse No. 30 (20-amp) in
engine compartment fuse/relay box. When ignition key is in ignition lock assembly, key interlock switch closes, providing voltage to key interlock solenoid and interlock control unit.
If shift lever is not in Park (parking pin switch on), interlock control unit energizes key interlock solenoid by completing the ground circuit. When key interlock solenoid is energized, ignition key
cannot be removed from ignition lock assembly. Key interlock switch and key interlock solenoid are located on ignition lock assembly. See Fig. 2. Parking pin switch is located on left side of shift lever.
Interlock control unit is located behind driver's side of instrument panel and contains an 8-pin harness connector. See Fig. 2.
Fig. 1: Locating A/T Gear Position Indicator & MIL Light Courtesy of AMERICAN HONDA MOTOR CO, INC.
Fig. 2: Locating Shift & Key Interlock System Components Courtesy of AMERICAN HONDA MOTOR CO, INC.
TRANSMISSION CONTROL MODULE (TCM)

The TCM receives information from various input devices and uses this information to control shift, linear and lock-up control solenoid valves. See Fig. 3. The TCM contains a self-diagnostic system
which stores a fault code if a failure is present in transaxle electronic control system. Fault code may also be referred to as Diagnostic Trouble Code (DTC) or flash code. DTC or flash code may be
retrieved to determine transaxle problem area. See SELF-DIAGNOSTIC SYSTEM. The TCM is located behind center of instrument panel. See Fig. 4.
Fig. 3: Identifying TCM Input & Output Devices Courtesy of AMERICAN HONDA MOTOR CO, INC.
Fig. 4: ECM, TCM, A/T Gear Position Switch & Brakelight Switch Courtesy of AMERICAN HONDA MOTOR CO, INC.
TCM INPUT DEVICES

Air Conditioning Signal

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 4 of 31
The A/C clutch relay delivers an input signal to TCM, indicating A/C operation. The A/C clutch relay is located at front left corner of engine compartment, near radiator. See Fig. 5.
Barometric Pressure Signal

Barometric pressure signal is delivered between Engine Control Module (ECM) and the TCM. The ECM contains a built-in barometric pressure sensor to determine atmospheric pressure. The ECM is
located behind center of instrument panel. See Fig. 4.
Brake Switch Signal

Brakelight switch delivers an input signal to TCM, indicating vehicle braking. Brakelight switch is also used in determining grade logic control. Brakelight switch is located on brake pedal support. See
Fig. 4.
Engine Coolant Temperature (ECT) Signal

ECT sensor delivers an input signal to TCM, indicating engine coolant temperature. The ECT sensor is located on cylinder head, below distributor and contains a Red/White wire and Green/Blue wire in
the electrical connector. See Fig. 6.
Engine Speed

Engine speed signal (RPM) is delivered to TCM from ignition control module in distributor assembly.
Engine Control Module (ECM)

Upshift, downshift and shift acknowledgment signals are delivered between the ECM and TCM. A 5- volt reference signal is present between ECM and TCM. The ECM is located behind center of
instrument panel. See Fig. 4.
Mainshaft & Countershaft Speed Signal

Mainshaft speed signal is delivered to TCM. Mainshaft speed sensor is located on side of transaxle. See Fig. 6. Countershaft speed signal is delivered to TCM. Countershaft speed sensor is located on
top of transaxle. See Fig. 6.
Service Check Connector

Service check connector is used when retrieving flash codes for transaxle electronic control system diagnosis. When a jumper wire is installed between electrical terminals of service check connector,
an input signal is delivered to TCM to display flash codes on "D4" indicator light. Service check connector is a 2-pin Blue colored harness connector located at passenger's corner of instrument panel.
See Fig. 7.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 5 of 31
Shift Position Signal

Shift position signal is delivered to TCM by the A/T gear position switch, located on driver's side of shift lever. See Fig. 2 or Fig. 4.
Throttle Position (TP) Sensor Signal

Throttle Position (TP) sensor delivers an input signal to TCM to indicate throttle position. The TP sensor is mounted on throttle body. See Fig. 6.
Vehicle Speed Sensor Signal

Vehicle speed Sensor (VSS) delivers an input signal to TCM to indicate vehicle speed. The VSS is located on top of transaxle. See Fig. 6.
Fig. 5: Locating A/C Clutch Relay
Courtesy of AMERICAN HONDA MOTOR CO, INC.
Fig. 6: Locating Input & Output Devices
Courtesy of AMERICAN HONDA MOTOR CO, INC.
Fig. 7: Locating Service Check Connector
Courtesy of AMERICAN HONDA MOTOR CO, INC.
TCM OUTPUT DEVICES

Shift Control Solenoid Valves

The TCM controls transaxle shifting by delivering an output signal to shift control solenoid valves "A" and "B" on shift control solenoid valve assembly. Solenoid valves are operated in accordance
with gear position. See SHIFT CONTROL SOLENOID VALVE OPERATION table. Shift control solenoid valve assembly is located on transaxle. See Fig. 6. Shift control solenoid valve "A"
has a Blue/Yellow wire, and solenoid valve "B" has a Green/White wire.
SHIFT CONTROL SOLENOID VALVE OPERATION
Shift Lever Position "D" Or "D4" (1st Gear)
"D" Or "D4" (2nd Gear) "D" Or "D4" (3rd Gear)
"D4" (4th)
"2" (2nd Gear) "1" (1st Gear)
"R" (Reverse)
Solenoid Valve "A" Off
On On
Off On
Off On
Solenoid Valve "B" On
On Off
Off On On
Off
Lock-Up Control Solenoid Valves

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 6 of 31
The TCM controls torque converter lock-up by delivering an output signal to lock-up control solenoid valves "A" and "B" on lock-up control solenoid valve assembly. Lock-up control solenoid
valves are activated in accordance with lock-up condition. See LOCK-UP CONTROL SOLENOID VALVE OPERATION table. Lock-up control solenoid valve assembly is located on transaxle. See
Fig. 6. Lock-up control solenoid valve "A" has a Yellow wire, and solenoid valve "B" has a Green/Black wire.
LOCK-UP CONTROL SOLENOID VALVE OPERATION
Lock-Up Condition No Lock-Up
Slight Lock-Up Half Lock-Up Full Lock-Up
Lock-Up During Deceleration
Solenoid Valve "A" Off
On On On
On
Solenoid Valve "B" Off
Off On On
(1)
(1) Solenoid valve will cycle on and off.
Linear Solenoid

The Linear solenoid is controlled by TCM according to engine torque. As engine torque changes, TCM will control linear solenoid which operates throttle valve for shift control. Linear solenoid is
located on transaxle. See Fig. 6.
"D4" Indicator Light

The "D4" indicator light is located on A/T gear position indicator on instrument panel. See Fig. 1. When ignition is first turned on, "D4" indicator light should illuminate for about 2 seconds, then turn
off, indicating light circuit is functioning properly. If a fault is present in transaxle electronic control system and a fault code is stored, TCM delivers an output signal to flash "D4" indicator light.
Interlock Control Unit

When A/T gear position switch is in Park, the TCM provides voltage to shift lock circuit at the interlock control unit, provided brake pedal is depressed and accelerator pedal is in idle position.
Interlock control unit then operates shift lock solenoid by controlling the ground circuit. When shift lock solenoid is energized, shift lever is released and can be moved.
Self-Diagnosis Indicator

If a fault is present in transaxle electronic control system and a DTC is stored, TCM will deliver an output signal (flash code) to illuminate and flash "D4" light. The "D4" light is located on A/T gear
position indicator on instrument panel. See Fig. 1. Flash code can be retrieved to identify problem area by installing a jumper wire or service tool between service check connector terminals. A DTC
(4-digit) "P" code can be retrieved by using a scan tool to identify problem area. Flash codes will be displayed by flashing "D4" light.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 7 of 31
TROUBLE SHOOTING

A/C SIGNAL

NOTE: If no A/C signal is present, torque converter lock-up clutch may not engage or cycle on and off.
1.
Start engine. Turn blower switch and A/C switch to the ON position. Check if A/C compressor clutch engages.
2. If A/C compressor clutch does not engage, check A/C system. See A/C-HEATER SYSTEM - MANUAL article in the AIR CONDITIONING & HEATING SERVICE & REPAIR section.
If A/C compressor clutch engages, turn engine off. Disconnect 26-pin TCM harness connector "A".
Start engine. Using a DVOM, measure voltage between 26-pin TCM harness connector "A", terminal No. 24 (Red/Blue wire) and terminals No. 13 or 26 (Brown/Black wire). Note voltage
with A/C compressor off.
If battery voltage is not present, go to next step. If battery voltage is present, A/C signal is okay. Check for loose TCM harness connections. If harness connections are okay, substitute
TCM with a known-good unit and recheck.
Repair open Red/Blue wire between 26-pin TCM harness connector "A", terminal No. 24 and A/C compressor clutch relay. The A/C compressor clutch relay is located at left front corner of
engine compartment, near radiator. See Fig. 5.
3.
4.
5.
BRAKELIGHT SIGNAL

NOTE: If no brakelight is present, transaxle may fail to shift from Park with
brake pedal depressed and accelerator pedal in idle position.
1.
Ensure brakelights come on when brake pedal is depressed. If brakelights come on, go to next step. If brakelights do not come on, check fuse No. 30 (20-amp) in engine compartment
fuse/relay box. If fuse is okay, repair brakelight signal circuit.
Ensure ignition is off. Disconnect 26-pin TCM harness connector "A" and 22-pin TCM harness connector "B". Using a DVOM, measure voltage between 22-pin TCM harness connector "B",
terminal No. 12 (Green/White wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires) with brake pedal depressed. If battery voltage is present, brakelight
signal to TCM is okay. Check for loose TCM harness connections. If harness connections are okay, substitute TCM with a known-good unit and recheck.
If battery voltage is not present, repair open in Green/White wire between 22-pin TCM harness connector "B", terminal No. 12 and brakelight switch. Brakelight switch is located on brake
pedal support. See Fig. 4.
2.
3.
SELF-DIAGNOSTIC SYSTEM

SYSTEM DIAGNOSIS

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 8 of 31
TCM monitors transaxle operation. TCM contains a self-diagnostic system which stores a DTC if a transaxle electronic control system failure is present. If a DTC is stored, TCM will illuminate and
flash "D4" light on A/T gear position indicator on instrument panel. See Fig. 1. If a transaxle electronic control system failure is suspected, and "D4" light on A/T gear position indicator does not
flash, perform appropriate test under "D4" INDICATOR LIGHT CIRCUIT CHECK. DTCs can be retrieved using a scan tool connected to Data Link Connector (DLC) located behind ashtray. Flash
code may also be retrieved for diagnosing transaxle electronic control system.
"D4" INDICATOR LIGHT CIRCUIT CHECK

"D4" Indicator Light Does Not Come On

1.
Turn ignition on. Ensure service connector shorting tool is not connected to service check connector. Shift to "D4" position. If "D4" indicator light does not illuminate, go to next step. If
"D4" indicator light illuminates, check for loose TCM harness connections. Replace TCM with a known-good unit if necessary and retest.
Turn ignition off. Disconnect 26-pin TCM harness connector "A". Using a DVOM, check for continuity between ground and 26-pin TCM harness connector "A", terminals No. 13 and 26
(Brown/Black wires). If continuity is present, go to next step. If continuity is not present, repair open or poor connection in appropriate Brown/Black wire.
Turn ignition on. Measure voltage at 26-pin TCM harness connector "A", between terminals No. 12 (Black/Yellow wire) and No. 13 (Brown/Black wire), then between terminals No. 25
(Black/Yellow wire) and No. 26 (Brown/Black wire). If battery voltage is present, go to next step. If battery voltage is not present, repair open or short in appropriate Black/Yellow wire
between TCM and engine compartment fuse/relay box.
Turn ignition off. Reconnect TCM harness connector. Connect a DVOM (backprobe) between 26-pin TCM harness connector "A", terminal No. 17 (Blue/Red wire) and terminals No. 13 or
26 (Brown/Black wires). Turn ignition on. Voltage should be present for 2 seconds. If DVOM indicates voltage as specified, go to next step. If no voltage was indicated, go to step 6).
5. Check for an open or short in Blue/Red wire between TCM and gauge assembly. Repair as necessary. If no problem is found, repair faulty "D4" indicator bulb or gauge assembly printed
circuit board.
Turn ignition off. Disconnect 26-pin TCM harness connector "A". Check Blue/Red wire for continuity between 26-pin TCM harness connector "A", terminal No. 17 and gauge assembly
harness connector terminal C3. If continuity is present, go to next step. If continuity is not present, repair open in Red/Blue wire.
Check for loose TCM harness connectors or faulty A/T gear position switch. Repair as necessary. If no problem is found, replace TCM with a known-good unit and retest.
2.
3.
4.
6.
7.
"D4" Indicator Light Remains On Constantly (Not Flashing)

1.
Turn ignition off. Disconnect 26-pin TCM harness connector "A". Turn ignition on. Using a DVOM, measure voltage between ground and 26-pin TCM harness connector "A", terminal
No. 17 (Blue/Red wire). If no voltage is present, go to next step. If voltage is present, repair Blue/Red wire for a short to power.
Turn ignition off. Reconnect TCM harness connector. Turn ignition on. Shift to any position except "D4". Measure voltage (backprobe) between ground and 26-pin TCM harness connector
2.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 9 of 31
"A", terminal No. 9 (Light Green/Black wire). If voltage is present, replace TCM. If no voltage is present, check Light Green/Black wire for a short to ground. Repair as necessary. If no
problem is found, replace A/T gear position indicator.
RETRIEVING FAULT CODES

NOTE: During diagnostics, ensure "D4" indicator light on A/T gear position indicator is not turned on by a fault in the PGM-FI system. The PGM-FI
system controls the fuel injection system. To repair PGM-FI system,
see appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section.
TESTS W/CODES - ODB-II (2.7L) - 1995
TESTS W/CODES - 2.7L V6 - 1996
After PGM-FI system has been repaired, clear fault codes. See CLEARING FAULT CODES. After fault codes have been cleared, road test vehicle for several minutes at over 30 MPH and
recheck fault codes.
NOTE: Before any diagnostic procedure, obtain radio anti-theft code from
customer. Note radio preset stations, as radio stations and clock
setting will be cleared and must be reset. Radio anti-theft code must be re-entered for radio operation.
Retrieving DTCs Using Scan Tool

1.
If a DTC is present, "D4" light on A/T gear position indicator will flash when ignition is turned on. To retrieve DTC using scan tool, turn ignition off.
Connect scan tool to 16-pin Data Link Connector (DLC) located behind ashtray. Turn ignition on. Scan tool will indicate DTCs. Follow scan tool manufactures instructions.
Once DTC is obtained, turn ignition off. Determine probable cause and symptom. See DTC/FLASH CODE IDENTIFICATION table. If any other DTCs except those listed are
displayed, see appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section.
2.
3.
TESTS W/CODES - ODB-II (2.7L) - 1995
TESTS W/CODES - 2.7L V6 - 1996
For trouble shooting of DTCs, see DIAGNOSTIC TESTS. If "D4" light does not flash or remains on, see appropriate test under "D4" INDICATOR LIGHT CIRCUIT CHECK.
Retrieving Flash Codes Using "D4" Light

1.
If a flash code is present, "D4" light on A/T gear position indicator will flash when ignition is turned on. To retrieve flash code, turn ignition off.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 10 of 31
2.
Install a jumper wire or service tool between service check connector electrical terminals. Service check connector is a Blue 2-pin electrical connector located under passenger's side of
instrument panel. See Fig. 7.
Turn ignition on. Flash codes will be displayed by short and long flashes of "D4" light on A/T gear position indicator. If the Malfunction Indicator Light (MIL) is also flashing, see
appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section.
3.
TESTS W/CODES - ODB-II (2.7L) - 1995
TESTS W/CODES - 2.7L V6 - 1996
NOTE: Repair MIL light codes first.
4.
A short flash indicates a single digit flash code. A long flash equals 10 short flashes. For example, if "D4" light flashes once, this is a Flash Code No. 1. If "D4" light flashes one long,
then 5 short flashes, this is a Flash Code No. 15. See Fig. 8.
Once flash code is obtained, turn ignition off. Remove jumper wire or service tool from service check connector. Determine probable cause and symptom. See DTC/FLASH CODE
IDENTIFICATION table. If any other flash codes except those listed are displayed, TCM is defective. For trouble shooting of flash codes, see DIAGNOSTIC TESTS.
5.
NOTE: If customer describes symptoms for DTC P0725/Flash Code 11, DTC
P1706/Flash Code 6 or DTC P1790/Flash Code 3, it may be necessary to test drive vehicle to recreate the symptom and then check for
trouble code with ignition still on.
Fig. 8: Identifying Flash Code Displays
Courtesy of AMERICAN HONDA MOTOR CO, INC.
DTC/FLASH CODE IDENTIFICATION
DTC/Flash Code

Indicator Light

(3)
(4) (5)
Probable Cause

Symptom
(1)
(2)
Number P0715/15
Condition Off
Defective Mainshaft Speed
Sensor Defective
Countershaft Speed Sensor
Defective Ignition Coil
Defective Shift Control System
Defective Lock-Up Control System
Transaxle Jerks Hard When Shifting
P0720/9
Flashes
Lock-Up Clutch Does Not Engage
P0725/11
Off
Lock-Up Clutch Does Not Engage
Fails To Shift, Stuck In 1st Or 4th Gears
Lock-Up Clutch Does Not Engage Or Remains
Engaged, Unstable Engine Idle
Remains In 4th Gear,
P0730
Off
P0740
Off
P0753/7
Flashes
Defective Shift

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 11 of 31
Control Solenoid "A"
Fails To Shift Other Than 1st-4th, 2nd-4th, Or 2nd-
3rd Gears Remains In 1st Or 4th
Gear
P0758/8
Flashes
Defective Shift Control Solenoid
"B" Defective A/T Gear
Position Switch
P1705/5
Flashes
Lock-Up Clutch Does Not Engage, Fails To
Shift Other Than 2nd-4th Gears
Lock-Up Clutch Does Not Engage, Lock-Up
Clutch Engages & Disengages, Fails To
Shift Other Than 2nd-4th Gears
Lock-Up Clutch Does Not Engage Or Remains
Engaged, Unstable Engine Idle
Lock-Up Clutch Does Not Engage
P1706/6
Off
Defective A/T Gear Position Switch
P1753/1
Flashes
Defective Lock-Up Control Solenoid
"A"
P1758/2
Flashes
Defective Lock-Up Control Solenoid
"B" Defective Linear
Control Solenoid "B"
P1768/16
Flashes
Lock-Up Clutch Does Not Engage, Transaxle
Jerks Hard When Shifting
Transaxle Jerks Hard When Shifting
P1786/14
Flashes
Shorted Or Open FAS Wire Between
TCM Terminal B19 & ECM, Defective
ECM Defective Throttle
Position Sensor Defective Vehicle
Speed Sensor Defective Engine
Coolant Temp Sensor
Defective Baro Sensor
(1) Number of blinks from "D4" light on A/T gear position indicator with jumper wire or service tool installed in service check connector.
(2) Operation of "D4" light on A/T gear position indicator.
P1790/3
Flashes Or Remains Off
Flashes
Lock-Up Clutch Does Not Engage
Lock-Up Clutch Does Not Engage
Lock-Up Clutch Does Not Engage
P1791/4
P1792/10
Flashes
P1794/13
Flashes
No Specific Symptoms
(3) Specified component for probable cause. Also check wiring and connections for the specified component.
(4) If transaxle fails to shift from Park with brake pedal depressed and accelerator pedal in idle

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 12 of 31
position, check brakelight signal. See BRAKELIGHT SIGNAL under TROUBLE SHOOTING.
(5) If lock-up clutch does not engage or does not cycle on and off, check A/C signal. See A/C SIGNAL under TROUBLE SHOOTING.
CLEARING FAULT CODES

NOTE: TCM memory can NOT be cleared using a scan tool. The following procedure must be used. Before clearing fault codes, obtain radio anti-
theft code from customer. Note radio preset stations, as radio stations
and clock setting will be cleared and must be reset. Radio anti-theft code must be reset for radio operation.
1.
Once repairs have been performed, fault codes must be cleared from TCM memory. Ensure ignition is off. Remove fuse No. 39 (7.5-amp) from engine compartment fuse/relay box for at
least 10 seconds. See Fig. 9. This will clear TCM memory.
Reinstall fuse. To re-enter radio anti-theft code, turn radio on. When CODE is displayed on radio, re-enter radio anti-theft code by using the radio station preset buttons. Reset clock and
radio stations.
2.
Fig. 9: Locating Fuse No. 39 (7.5-Amp)
Courtesy of AMERICAN HONDA MOTOR CO, INC.
DIAGNOSTIC TESTS

NOTE: Diagnostic codes are identified by "P" series code and then flash code,
example: P0715/15 (DTC code/flash code).
NOTE: During diagnostic testing, refer to illustrations for harness connector
and wire terminal identification. See Fig. 10 -Fig. 12.
Fig. 10: Identifying TCM Harness Connectors & Terminals Courtesy of AMERICAN HONDA MOTOR CO, INC.
DTC P0715/15: MAINSHAFT SPEED SENSOR

NOTE: DTC P0715 does NOT confirm an electrical problem in mainshaft speed
sensor or circuit. This DTC can also be caused by a mechanical problem in transaxle.
1.
Ensure mainshaft and countershaft speed sensors are installed properly. See COUNTERSHAFT SPEED SENSOR or MAINSHAFT SPEED SENSOR under
REMOVAL & INSTALLATION. Disconnect mainshaft speed sensor harness connector. Using a DVOM, measure resistance between sensor terminals. See MAINSHAFT SPEED
SENSOR under COMPONENT TESTING.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 13 of 31
2.
If resistance is not 400-600 ohms, replace mainshaft speed sensor. If resistance is 400-600 ohms, disconnect 22-pin TCM harness connector "B". Check for continuity between ground
and 22-pin TCM harness connector "B", terminals No. 10 (Orange/Blue wire) and No. 17 (White/Blue wire). See Fig. 10.
If continuity is present, repair short to ground in Orange/Blue wire or White/Blue wire between TCM and mainshaft speed sensor. If continuity is not present, reconnect mainshaft speed
sensor harness connector. Measure resistance between 22-pin PCM harness connector "B", terminals No. 10 (Orange/Blue wire) and No. 17 (White/Blue wire).
If resistance is not 400-600 ohms, go to next step. If resistance is 400-600 ohms, go to DTC P0720 (FLASH CODE 9). Check for loose TCM harness connectors. Replace TCM with a
known-good unit if necessary.
Disconnect mainshaft speed sensor harness connector. Check Orange/Blue wire for continuity between 22-pin TCM harness connector "B", terminal No. 10 and mainshaft speed sensor
harness connector. If continuity is present, go to next step. If continuity is not present, repair open in Orange/Blue wire between 22-pin TCM harness connector and mainshaft speed sensor
harness connector.
Check White/Blue wire for continuity between 22-pin TCM harness connector "B", terminal No. 17 and mainshaft speed sensor harness connector. If continuity is present, check for loose
TCM harness connectors. Replace TCM with a known-good unit if necessary. If continuity is not present, repair open in White/Blue wire between 22-pin TCM harness connector and
mainshaft speed sensor harness connector.
3.
4.
5.
6.
DTC P0720/9: COUNTERSHAFT SPEED SENSOR

Ensure countershaft speed sensor is installed properly. See COUNTERSHAFT SPEED SENSOR under REMOVAL & INSTALLATION. Disconnect countershaft speed sensor
harness connector. Using a DVOM, measure resistance between sensor terminals. See COUNTERSHAFT SPEED SENSOR under COMPONENT TESTING.
If resistance is not 400-600 ohms, replace countershaft speed sensor. If resistance is 400-600 ohms, disconnect 22-pin TCM harness connector "B". Check for continuity between ground
and 22-pin TCM harness connector "B", terminals No. 8 (Blue/Yellow wire) and No. 9 (Blue/Green wire). See Fig. 10.
If continuity is present, repair short to ground in Blue/Yellow wire or Blue/Green wire between TCM and countershaft speed sensor. If continuity is not present, reconnect countershaft speed
sensor harness connector. Measure resistance between 22-pin TCM harness connector "B", terminals No. 8 (Blue/Yellow wire) and No. 9 (Blue/Green wire).
If resistance is 400-600 ohms, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary. If resistance is not 400-600 ohms, repair loose connection or
open in Blue/Yellow wire or Blue/Green wire between 22-pin TCM harness connector and countershaft speed sensor harness connector.
1.
2.
3.
4.
DTC P0725/11: IGNITION COIL

1.
Disconnect 26-pin TCM harness connector "A". Turn ignition on. Using a DVOM, measure voltage between 26-pin TCM harness connector "A", terminal No. 5 (Blue wire) and terminals
No. 13 or 26 (Brown/Black wires). See Fig. 10.
2. If battery voltage is present, check for loose TCM harness connectors. Replace TCM with a

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 14 of 31
known-good unit if necessary. If battery voltage is not present, repair open or short in Blue wire between ignition coil and 26-pin TCM harness connector "A".
DTC P0730: SHIFT CONTROL SYSTEM

NOTE: DO NOT perform this DTC test until all other DTCs have been repaired
first.
1.
Road test vehicle at over 12 MPH for more than 30 seconds in 2nd, 3rd and 4th gear. Using scan tool, check for any other DTCs. If any other DTCs are present, repair those DTCs first,
then recheck for DTC P0730. If no other DTCs are present, go to next step.
2. Test clutch pressure. See HYDRAULIC PRESSURE TEST under TESTING in TRANSMISSIONS OVERHAUL - A/T - MPZA (V6 2.7L) article. If clutch pressure is
within specification, go to next step. If clutch pressure is not within specification, repair hydraulic system as necessary. See HYDRAULIC PRESSURE TROUBLE SHOOTING table
under HYDRAULIC PRESSURE TEST in TRANSMISSIONS OVERHAUL - A/T - MPZA (V6 2.7L) article.
Replace shift control solenoid valve assembly. See SHIFT CONTROL SOLENOID VALVES under REMOVAL & INSTALLATION. Turn ignition off and clear codes. See
CLEARING FAULT CODES under SELF-DIAGNOSTIC SYSTEM. Road test vehicle at over 12 MPH for more than 30 seconds in 2nd, 3rd and 4th gear. Recheck DTCs. If P0730
returns, go to next step. If P0730 does not return, system is okay.
Replace linear solenoid assembly. See LINEAR SOLENOID
INSTALLATION. Turn ignition off and clear codes. See CLEARING FAULT CODES under SELF-DIAGNOSTIC SYSTEM. Road test vehicle at over 12 MPH for more than 30
seconds in 2nd, 3rd and 4th gear. Recheck DTCs. If P0730 returns, replace transaxle. If P0730 does not return, system is okay.
3.
Under REMOVAL &
4.
DTC P0740: LOCK-UP CONTROL SYSTEM

NOTE: DO NOT perform this DTC test until all other DTCs have been repaired
first.
1.
Using scan tool, check for any other DTCs. If any other DTCs are present, repair those DTCs first, then recheck for DTC P0740. If no other DTCs are present, go to next step.
Test line pressure. See HYDRAULIC PRESSURE TEST under TESTING in TRANSMISSIONS OVERHAUL - A/T - MPZA (V6 2.7L) article. If line pressure is within
specification, go to next step. If line pressure is not within specification, repair hydraulic system as necessary. See HYDRAULIC PRESSURE TROUBLE SHOOTING table under
HYDRAULIC PRESSURE TEST in TRANSMISSIONS OVERHAUL - A/T article. Test clutch pressure. If clutch pressure is within specification, go to next step. If clutch
pressure is not within specification, repair hydraulic system as necessary. See HYDRAULIC PRESSURE TROUBLE SHOOTING table under HYDRAULIC PRESSURE TEST in
TRANSMISSIONS OVERHAUL - A/T article.
Replace lock-up control solenoid valve assembly. See LOCK
VALVES under REMOVAL & INSTALLATION. Turn ignition off and clear codes. See
CLEARING FAULT CODES under SELF-DIAGNOSTIC SYSTEM. Road test vehicle at
2.
3.
-
UP CONTROL SOLENOID
4.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 15 of 31
over 50 MPH for more than one minute. Recheck DTCs. If P0740 returns, go to next step. If P0740 does not return, system is okay.
Replace linear solenoid assembly. See LINEAR SOLENOID
INSTALLATION. Turn ignition off and clear codes. See CLEARING FAULT CODES under SELF-DIAGNOSTIC SYSTEM. Road test vehicle at over 50 MPH for more than one
minute. Recheck DTCs. If P0740 returns, go to next step. If P0740 does not return, system is okay.
6. Replace torque converter. Turn ignition off and clear codes. See CLEARING FAULT CODES under SELF-DIAGNOSTIC SYSTEM. Road test vehicle at over 50 MPH for more
than one minute. Recheck DTCs. If P0740 returns, replace transaxle. If P0740 does not return, system is okay.
5.
Under REMOVAL &
DTC P0753/7: SHIFT CONTROL SOLENOID VALVE "A"

1.
Disconnect 26-pin TCM harness connector "A" and 22-pin TCM harness connector "B". Turn ignition on. Using a DVOM, measure voltage between 22-pin TCM harness connector "B",
terminal No. 20 (Light Green/Black wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10. If voltage is about 5 volts, go to next step. If
voltage is not as specified, repair open or short in Light Green/Black wire between 22-pin TCM harness connector "B" and ECM.
Measure voltage between 26-pin TCM harness connector "A", terminal No. 3 (Blue/Yellow wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage is not present, go to next
step. If voltage is present, repair Blue/Yellow wire for a short to power.
Turn ignition off. Measure resistance between 26-pin TCM harness connector "A", terminal No. 3 (Blue/Yellow wire) and terminals No. 13 or 26 (Brown/Black wires). If resistance is not
12-20 ohms, go to next step. If resistance is 12-20 ohms, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary.
Disconnect shift control solenoid valve harness connector. Check for continuity between 26- pin TCM harness connector "A", terminal No. 3 (Blue/Yellow wire) and terminals No. 13 or 26
(Brown/Black wires). If continuity is not present, go to next step. If continuity is present, repair Blue/Yellow wire for a short to ground between 26-pin TCM harness connector "A" and shift
control solenoid valve "A".
Measure resistance between ground and Blue/Yellow wire at shift control solenoid valve harness connector (solenoid side). If resistance is not 12-20 ohms, replace shift control
solenoid valve assembly. If resistance is 12-20 ohms, repair open in Blue/Yellow wire between shift control solenoid valve "A" and harness connector.
2.
3.
4.
5.
DTC P0758/8: SHIFT CONTROL SOLENOID VALVE "B"

1.
Disconnect 26-pin TCM harness connector "A" and 22-pin TCM harness connector "B". Turn ignition on. Using a DVOM, measure voltage between 22-pin TCM harness connector "B",
terminal No. 20 (Light Green/Black wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10. If voltage is about 5 volts, go to next step. If
voltage is not as specified, repair open or short in Light Green/Black wire between 22-pin TCM harness connector "B" and ECM.
Measure voltage between 26-pin TCM harness connector "A", terminal No. 2 (Green/White wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage is not present, go to next
step. If voltage is present, repair short to power in Green/White wire.
2.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 16 of 31
3.
Turn ignition off. Measure resistance between 26-pin TCM harness connector "A", terminal No. 2 (Green/White wire) and terminals No. 13 or 26 (Brown/Black wires). If resistance is not
12-20 ohms, go to next step. If resistance is 12-20 ohms, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary.
Disconnect shift control solenoid valve harness connector. Check for continuity between 26- pin TCM harness connector "A", terminal No. 2 (Green/White wire) and No. 13 or 26
(Brown/Black wires). If continuity is not present, go to next step. If continuity is present, repair short to ground in Green/White wire between 26-pin TCM harness connector "A" and shift
control solenoid valve "B".
Measure resistance between ground and Green/White wire at shift control solenoid valve harness connector (solenoid side). If resistance is not 12-20 ohms, replace shift control
solenoid valve assembly. If resistance is 12-20 ohms, repair open in Green/White wire between shift control solenoid valve "B" and harness connector.
4.
5.
DTC P1705/5: A/T GEAR POSITION SWITCH (SHORT)

NOTE: DTC P1705 is set when TCM receives 2 gear position signals at the
same time.
1.
Turn ignition on. If any A/T gear position indicator lights remain illuminated when gear selector is moved from that gear, go to next step. If all A/T gear position indicator lights turn
off when gear selector is moved from that gear, system is okay at this time.
Shift through all gear positions except Reverse. Using a DVOM, measure voltage between 26- pin TCM harness connector "A", terminal No. 11 (Green/Red wire) and terminals No. 13 or 26
(Brown/Black wires). See Fig. 10. If battery voltage is present, go to next step. If battery voltage is not present, check for a short in Green/Red wire between 26-pin TCM harness
connector "A" and A/T gear position indicator, or A/T gear position switch. Repair as necessary. If Green/Red wire is okay, check for loose TCM harness connectors. Replace TCM
with a known-good unit if necessary.
Shift through all gear positions except Neutral and Park. Measure voltage between 26-pin TCM harness connector "A", terminal No. 10 (Light Green wire) and terminals No. 13 or 26
(Brown/Black wires). If battery voltage is present, go to next step. If battery voltage is not present, check for a short in Light Green wire between 26-pin TCM harness connector "A" and
A/T gear position indicator, or A/T gear position switch. Repair as necessary. If Light Green wire is okay, check for loose TCM harness connectors. Replace TCM with a known-good unit
if necessary.
4. Shift through all gear positions except "D4". Measure voltage between 26-pin TCM harness connector "A", terminal No. 9 (Light Green/Black wire) and terminals No. 13 or 26
(Brown/Black wires). If battery voltage is present, go to next step. If battery voltage is not present, check for a short in Light Green/Black wire between 26-pin TCM harness connector
"A" and A/T gear position switch. Repair as necessary. If Light Green/Black wire is okay, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary.
5. Shift through all gear positions except "D(3)". Measure voltage between 26-pin TCM harness connector "A", terminal No. 8 (Green/Blue wire) and terminals No. 13 or 26 (Brown/Black
wires). If battery voltage is present, go to next step. If battery voltage is not present, check for a short in Green/Blue wire between 26-pin TCM harness connector "A" and A/T gear position
indicator, or A/T gear position switch. Repair as necessary. If Green/Blue wire is okay, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary.
2.
3.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 17 of 31
6.
Shift through all gear positions except "2". Measure voltage between 26-pin TCM harness connector "A", terminal No. 7 (Green/Yellow wire) and terminals No. 13 or 26 (Brown/Black
wires). If battery voltage is present, go to next step. If battery voltage is not present, check for a short in Green/Yellow wire between 26-pin TCM harness connector "A" and A/T gear position
indicator, or A/T gear position switch. Repair as necessary. If Green/Yellow wire is okay, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary.
7. Shift through all gear positions except "1". Measure voltage between 26-pin TCM harness connector "A", terminal No. 6 (Light Green/White wire) and terminals No. 13 or 26
(Brown/Black wires). If battery voltage is present, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary. If battery voltage is not present, check for
a short in Light Green/White wire between 26-pin TCM harness connector "A" and A/T gear position indicator, or A/T gear position switch. Repair as necessary. If Light Green/White wire
is okay, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary.
DTC P1706/6: A/T GEAR POSITION SWITCH (OPEN)

1.
Turn ignition on. If any A/T gear position indicator lights remain on when gear selector is moved from that gear, go to next step. If all A/T gear position indicator lights turn off when
gear selector is moved from that gear, system is okay at this time.
Shift to Reverse. Using a DVOM, measure voltage between 26-pin TCM harness connector "A", terminal No. 11 (Green/Red wire) and terminals No. 13 or 26 (Brown/Black wires). See
Fig. 10. If voltage is not present, go to next step. If voltage is present, repair open in Green/Red wire between 26-pin TCM harness connector "A" and A/T gear position switch.
Shift to Neutral or Park. Measure voltage between 26-pin TCM harness connector "A", terminal No. 10 (Light Green wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage
is not present, go to next step. If voltage is present, repair open in Light Green wire between 26-pin TCM harness connector "A" and A/T gear position indicator.
Shift to "D4" position. Measure voltage between 26-pin TCM harness connector "A", terminal No. 9 (Light Green/Black wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage is
not present, go to next step. If voltage is present, repair open in Light Green/Black wire between 26-pin TCM harness connector "A" and A/T gear position switch.
5. Shift to "D" position. Measure voltage between 26-pin TCM harness connector "A", terminal No. 8 (Green/Blue wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage is not
present, go to next step. If voltage is present, repair open in Green/Blue wire between 26-pin TCM harness connector "A" and A/T gear position switch.
Shift to "2" position. Measure voltage between 26-pin TCM harness connector "A", terminal No. 7 (Green/Yellow wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage is not
present, go to next step. If voltage is present, repair open in Green/Yellow wire between 26-pin TCM harness connector "A" and A/T gear position switch.
Shift to "1" position. Measure voltage between 26-pin TCM harness connector "A", terminal No. 6 (Light Green/White wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage is
not present, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary. If voltage is present, repair open in Light Green/White wire between 26-pin TCM
harness connector "A" and A/T gear position switch.
2.
3.
4.
6.
7.
DTC P1753/1: LOCK-UP CONTROL SOLENOID VALVE "A"

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 18 of 31
1.
Disconnect 26-pin TCM harness connector "A" and 22-pin TCM harness connector "B". Turn ignition on. Using a DVOM, measure voltage between 22-pin TCM harness connector "B",
terminal No. 20 (Light Green/Black wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10. If voltage is about 5 volts, go to next step. If
voltage is not as specified, repair open or short in Light Green/Black wire between 22-pin TCM harness connector "B" and ECM.
Measure voltage between 26-pin TCM harness connector "A", terminal No. 16 (Yellow wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage is not present, go to next step. If
voltage is present, repair short to power in Yellow wire.
Turn ignition off. Measure resistance between 26-pin TCM harness connector "A", terminal No. 16 (Yellow wire) and terminals No. 13 or 26 (Brown/Black wires). If resistance is not 12-
20 ohms, go to next step. If resistance is 12-20 ohms, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary.
Disconnect lock-up control solenoid valve harness connector. Check for continuity between 26-pin TCM harness connector "A", terminal No. 16 (Yellow wire) and terminals No. 13 or 26
(Brown/Black wires). If continuity is not present, go to next step. If continuity is present, repair short to ground in Yellow wire between 26-pin TCM harness connector "A" and lock-up
control solenoid valve "A".
Measure resistance of Yellow wire between ground and lock-up control solenoid valve harness connector (solenoid side). If resistance is not 12-20 ohms, replace lock-up control solenoid
valve assembly. If resistance is 12-20 ohms, repair open in Yellow wire between lock-up control solenoid valve "A" and harness connector.
2.
3.
4.
5.
DTC P1758/2: LOCK-UP CONTROL SOLENOID VALVE "B"

1.
Disconnect 26-pin TCM harness connector "A" and 22-pin TCM harness connector "B". Turn ignition on. Using a DVOM, measure voltage between 22-pin TCM harness connector "B",
terminal No. 20 (Light Green/Black wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10. If voltage is about 5 volts, go to next step. If
voltage is not as specified, repair open or short in Light Green/Black wire between 22-pin TCM harness connector "B" and ECM.
Measure voltage between 26-pin TCM harness connector "A", terminal No. 15 (Green/Black wire) and terminals No. 13 or 26 (Brown/Black wires). If voltage is not present, go to next
step. If voltage is present, repair short to power in Green/Black wire.
Turn ignition off. Measure resistance between 26-pin TCM harness connector "A", terminal No. 15 (Green/Black wire) and terminals No. 13 or 26 (Brown/Black wires). If resistance is not
12-20 ohms, go to next step. If resistance is 12-20 ohms, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary.
Disconnect lock-up control solenoid valve harness connector. Check for continuity between 26-pin TCM harness connector "A", terminal No. 15 (Green/Black wire) and terminals No. 13
or 26 (Brown/Black wires). If continuity is not present, go to next step. If continuity is present, repair short to ground in Green/Black wire between 26-pin TCM harness connector "A" and
lock-up control solenoid valve "B".
Measure resistance of Green/Black wire between ground and lock-up control solenoid valve harness connector (solenoid side). If resistance is not 12-20 ohms, replace lock-up control
solenoid valve assembly. If resistance is 12-20 ohms, repair open in Green/Black wire between lock-up control solenoid valve harness connector "B" and harness connector.
2.
3.
4.
5.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 19 of 31
DTC P1768/16: LINEAR SOLENOID

1.
Disconnect linear solenoid harness connector. Using a DVOM, measure resistance of linear solenoid. If resistance is about 5 ohms, go to next step. If resistance is not as specified, replace
linear solenoid assembly.
2. Disconnect 22-pin TCM harness connector "B" and 26-pin TCM harness connector "A". Check for continuity between ground and 22-pin TCM harness connector "B", terminal No. 1 (Red
wire), then between ground and 26-pin TCM harness connector "A", terminal No. 1 (White wire). See Fig. 10. If continuity is not present, go to next step. If continuity is present, repair
short between Red wire and White wire.
Reconnect linear solenoid harness connector. Measure resistance between 22-pin TCM harness connector "B", terminal No. 1 (Red wire) and 26-pin TCM harness connector "A", terminal
No. 1 (White wire). If resistance is about 5 ohms, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary. If resistance is not as specified, repair open
or poor connection in Red wire or White wire between linear solenoid and 22-pin TCM harness connector "B", or 26-pin TCM harness connector "A".
3.
DTC P1786/14: FAS SIGNAL

1.
Start engine and allow it to reach normal operating temperature. Shift to Park. Cycle key off and on and wait for 2 seconds. Using a DVOM, measure voltage between 22-pin TCM harness
connector "B", terminal No. 19 (Brown/White wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10. If voltage is about 5 volts, check for
loose TCM harness connectors. Replace TCM with a known-good unit if necessary. If voltage is not as specified, go to net step.
Turn ignition off. Disconnect 22-pin TCM harness connector "B". Turn ignition on. Measure voltage between 26-pin ECM harness connector "A", terminals No. 22 (Brown/White wire)
and No. 26 (Brown/Black wire). See Fig. 11. If voltage is about 5 volts, go to next step. If voltage is not as specified, go to step 4).
Turn ignition off. Check Brown/White wire for continuity between 26-pin ECM harness connector "A", terminal No. 22 and 22-pin TCM harness connector "B", terminal No. 19. If
continuity is not present, repair open in Brown/White wire between ECM and TCM. If continuity is present, check for loose TCM harness connectors. Replace TCM with a known-
good unit if necessary.
Turn ignition off. Disconnect 26-pin ECM harness connector "A". Check for continuity between ground and 26-pin ECM harness connector "A", terminal No. 22 (Brown/White wire),
or between ground and 22-pin TCM harness connector "B", terminal No. 19 (Brown/White wire). If continuity is not present, check for loose TCM harness connectors. Replace TCM with
a known-good unit if necessary. If continuity is present, repair short in Yellow wire between ECM and TCM.
2.
3.
4.
Fig. 11: Identifying 26-Pin ECM Harness Connector "A" Terminals Courtesy of AMERICAN HONDA MOTOR CO, INC.
DTC P1790/3: THROTTLE POSITION (TP) SENSOR

1. Turn ignition on. Using scan tool, check for any other DTCs. Check for flashing Malfunction

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 20 of 31
Indicator Light (MIL). If any other DTCs are present or MIL is flashing, repair those DTCs first, then recheck for DTC P1790. If no other DTCs are present, and MIL is not flashing, go to
next step.
Turn ignition off. Disconnect 22-pin TCM harness connector "B" and 26-pin TCM harness connector "A". Turn ignition on. Measure voltage between 22-pin TCM harness connector "B",
terminal No. 20 (Light Green/Black wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10. If voltage is about 5 volts, go to next step. If
voltage is not as specified, repair open or short in Light Green/Black wire between 22-pin TCM harness connector "B" and ECM.
Measure voltage between 22-pin TCM harness connector "B", terminal No. 4 (Red/Black wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). If
voltage is.4-.6 volt, check for loose TCM harness connectors. Replace TCM with a known- good unit if necessary. If voltage is not as specified, repair open or short in Red/Black wire
between TCM and TP sensor.
2.
3.
DTC P1791/4: VEHICLE SPEED SENSOR (VSS)

1.
Ensure speedometer operates properly. If speedometer operates properly, go to next step. If speedometer does not operate properly, see VEHICLE SPEED SENSOR (VSS) under
COMPONENT TESTING.
2. Raise and support vehicle. Block one front wheel. Place gear selector in Neutral. Turn ignition off. Disconnect 22-pin TCM harness connector "B" and 26-pin TCM harness connector "A".
Turn ignition on. While rotating unblocked front wheel and using a DVOM, measure voltage between 22-pin TCM harness connector "B", terminal No. 5 (Orange wire) and 26-pin TCM
harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10.
If voltage alternates from zero to about 5 volts, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary. If voltage does not alternate as specified,
check for an open or short in Orange wire between TCM and VSS. If wire is okay, see VEHICLE SPEED SENSOR (VSS) under COMPONENT TESTING.
3.
DTC P1792/10: ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1.
Turn ignition on. Using scan tool, check for any other DTCs. Check for flashing Malfunction Indicator Light (MIL). If any other DTCs are present or MIL is flashing, repair those DTCs
first, then recheck for DTC P1792. If no other DTCs are present and MIL is not flashing, go to next step.
Turn ignition off. Disconnect 22-pin TCM harness connector "B" and 26-pin TCM harness connector "A". Turn ignition on. Measure voltage between 22-pin TCM harness connector "B",
terminal No. 20 (Light Green/Black wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10. If voltage is about 5 volts, go to next step. If
voltage is not as specified, repair open or short in Light Green/Black wire between 22-pin TCM harness connector "B" and ECM.
Turn ignition off. Reconnect TCM harness connectors. Start engine and allow it to reach normal operating temperature. Measure voltage (backprobe) between 22-pin TCM harness
connector "B", terminal No. 3 (Red/White wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). If voltage is less than one volt, check for loose
TCM harness connectors. Replace TCM with a known-good unit if necessary. If voltage is equal to or greater than one volt, repair open or short in Red/White wire between TCM and
2.
3.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 21 of 31
ECT sensor.
DTC P1794/13: BAROMETRIC PRESSURE (BARO) SENSOR

NOTE: Baro sensor is built into ECM.
1.
Turn ignition off. Disconnect 22-pin TCM harness connector "B" and 26-pin TCM harness connector "A". Turn ignition on. Using a DVOM, measure voltage between 22-pin TCM
harness connector "B", terminal No. 20 (Light Green/Black wire) and 26-pin TCM harness connector "A", terminals No. 13 or 26 (Brown/Black wires). See Fig. 10. If voltage is about 5
volts, go to next step. If voltage is not as specified, repair open or short in Light Green/Black wire between 22-pin TCM harness connector "B" and ECM.
Turn ignition off. Disconnect 22-pin ECM harness connector "D". Check Blue/White wire for continuity between 22-pin ECM harness connector "D", terminal No. 3 and 22-pin TCM
harness connector "B" terminal No. 2. See Fig. 12. If continuity is present, go to next step. If continuity is not present, repair open in Blue/White wire between ECM and TCM.
Check for continuity between ground and 22-pin ECM harness connector "D", terminal No. 3 (Blue/White wire), or between ground and 22-pin TCM harness connector "B", terminal No. 2
(Blue/White wire). If continuity is not present, check for loose TCM harness connectors. Replace TCM with a known-good unit if necessary. If continuity is present, repair short to
ground in Blue/White wire.
2.
3.
Fig. 12: Identifying ECM Harness Connector "D" Terminals Courtesy of AMERICAN HONDA MOTOR CO, INC.
SYSTEM TESTING

A/T GEAR POSITION INDICATOR

NOTE: If necessary, refer to wiring schematic when checking component wiring. See Fig. 13.
1.
Remove instrument panel gauge assembly from instrument panel. Disconnect harness connectors from rear of instrument panel gauge assembly. See Fig. 14.
Using a DVOM, check for voltage and continuity at specified harness connectors and terminals. See Fig. 15. If necessary, check ground connections G402 or G404. Ground
connection G402 is located at passenger's side front corner, behind instrument panel. Ground connection G404 is located behind driver's side of center console. See Fig. 16.
If necessary, check fuse No. 1 (10-amp) located in instrument panel fuse/relay box, or fuse No. 32 (15-amp) located in engine compartment fuse/relay box.
2.
3.
Fig. 13: A/T Gear Position Indicator Wiring Schematic Courtesy of AMERICAN HONDA MOTOR CO, INC.
Fig. 14: Instrument Panel Gauge Assembly Harness Connectors Courtesy of AMERICAN HONDA MOTOR CO, INC.

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 22 of 31
Fig. 15: Testing A/T Gear Position Indicator
Courtesy of AMERICAN HONDA MOTOR CO, INC.
Fig. 16: Locating Ground Connections
Courtesy of AMERICAN HONDA MOTOR CO, INC.
SHIFT & KEY INTERLOCK SYSTEMS

NOTE: For system testing, refer to appropriate wiring diagram. See WIRING
DIAGRAMS. To check individual components, see COMPONENT TESTING.
1.
To check system operation, ensure shift lever is in Park. Turn ignition on. Depress brake pedal with accelerator pedal in idle position.
If shift lock solenoid clicks, system is working properly. If shift lock solenoid fails to click, see INTERLOCK CONTROL UNIT under COMPONENT TESTING. If shift lever cannot be
moved from Park, check for proper installation procedure of shift lock solenoid. See SHIFT LOCK SOLENOID under REMOVAL & INSTALLATION. If shift lock solenoid installation
is okay, test A/T gear position switch, see A/T GEAR POSITION SWITCH.
2.
COMPONENT TESTING

A/T GEAR POSITION SWITCH

NOTE: The A/T gear position switch also contains back-up light switch and
neutral position switch. Back-up light switch and neutral position
switch can also be checked when checking A/T gear position switch.
1.
Remove center console. Disconnect both the 12-pin and 2-pin harness connectors from A/T gear position switch. Note harness connector terminal identification. See Fig. 17.
Using a DVOM, check for continuity between specified terminal(s) with shift lever in indicated positions. See A/T GEAR POSITION SWITCH CONTINUITY table.
2.
NOTE: Check for continuity while moving shift lever back and forth in free play area of each gear position. DO NOT touch push button
on shift lever when checking continuity.
If continuity is not as specified, A/T gear position switch may require adjustment. See A/T GEAR POSITION SWITCH under REMOVAL & INSTALLATION. If correct continuity
cannot be obtained by adjusting A/T gear position switch, replace switch assembly.
3.
A/T GEAR POSITION SWITCH CONTINUITY
Continuity Between Terminals
Application
With Cruise Control
A/T Gear Position Switch
Shift Lever Position
"P"
F & I

1/27/2012
AUTOMATIC TRANSMISSION DIAGNOSIS - MPZA -1996 Honda Accord EX
Page 23 of 31
A/T Gear Position Switch A/T Gear Position Switch
A/T Gear Position Switch A/T Gear Position Switch
A/T Gear Position Switch A/T Gear Position Switch
Back-Up Light Switch Neutral Position Switch
Neutral Position Switch Without Cruise Control
A/T Gear Position Switch A/T Gear Position Switch
A/T Gear Position Switch A/T Gear Position Switch
A/T Gear Position Switch A/T Gear Position Switch
A/T Gear Position Switch Back-Up Light Switch
Neutral Position Switch Neutral Position Switch
"R" "N"
"D4" "D"
"2" "1"
"R" "P"
"N"
I & J I & K
A, E & I A, D & I
A, C & I B & I
G & H L & M
L & M
"P" "R"
"N" "D4"
"D" "2"
"1" "R"
"P" "N"
F & I I & J
I & K E & I
D & I C & I
B & I G & H
L & M L & M
Fig. 17: A/T Gear Position Switch Harness Connector Terminals Courtesy of AMERICAN HONDA MOTOR CO, INC.
BRAKELIGHT SWITCH

Disconnect harness connector from brakelight switch, located on brake pedal support. See Fig. 4. Note brakelight switch terminal identification. Se

Rivermikerat
Jan 28, 2012.


AD