Mechanics

ISUZU RODEO SENSOR PROBLEM

2002 Isuzu Rodeo • 180,000 miles

Truck runs but spitts and sputters and misfires, has codes P0175, P1312, P0300, P0155 showing. Have changed out the MAF changed the plugs, replaced O2 sensor on bank 2 sensor 1 have used cleaner on the throttle body. Have used injector cleaner in gas and used heet gas dryer also. I have a teck working on it now and he said that he found a jumper wire at the computer on the brown wire did not know at this time where it went. Do you have any suggestions? Car smooths out and runs fine some of the time afer it warms up but not great.
Thanks
Grady
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Grady01
December 29, 2012.



DTC P0155: BANK 2 HEATED OXYGEN SENSOR NO. 1 - HEATER CIRCUIT
NOTE: Always inspect a faulty Heated Oxygen Sensor (HO2S) for contamination and correct cause before installing a new HO2S. Bank 2 refers to left cylinder bank.

Diagnostic Aids
An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire onnection, and damaged harness.

Using scan tool, monitor signal voltage while wiggling HO2S related connectors and wiring harness with a warm engine running at part throttle in closed loop. If a failure is induced, signal voltage will change from normal fluctuating voltage to a fixed voltage. A change in voltage will assist in isolating location of fault. DO NOT solder HO2S wires. If DTC cannot be duplicated, reviewing scan tool FAILURE RECORDS
data can be useful in determining mileage and frequency of DTC occurrence.

DTC P0175: BANK 2 FUEL TRIM SYSTEM RICH
Diagnostic Aids
An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. If harness appears to be okay, use scan tool to observe sensor readings while moving connectors and harnesses. A change in display will indicate location of fault. If DTC cannot be duplicated, reviewing scan tool FAILURE RECORDS data can be useful in determining mileage and frequency of DTC occurrence.

DTCs other than P0172 and P0175 may indicate a condition which may cause a lean condition. Repairing condition caused by other DTC(s) may correct DTC P0172 or P0175.

DTC P0300: ENGINE MISFIRE DETECTED

Diagnostic Aids

Scan tool message MISFIRE CUR. #1-6 is helpful for determining if only a single cylinder is affected by misfire. If scan tool displays MISFIRE CUR. #1-6, check suspect ignition coil for cracks or damage. If problem is present, substitute a known-good ignition coil, or swap ignition coils cylinder-to-cylinder. If misfire follows coil, replace suspect ignition coil. If misfire is random check following: l Check PCM and system grounds. Ensure that all grounds are clean and secure.
L Check MAF sensor.
L Check for disconnected or damaged vacuum hoses. Check for vacuum leaks at EGR valve, throttle body and intake manifold.
L Perform FUEL SYSTEM PRESSURE TEST. Check for faulty fuel pump, plugged fuel filter or suspect fuel pressure regulator.
L Check fuel injectors. Perform FUEL INJECTOR BALANCE TEST. Also check condition of fuel injector "O" ring seals.
L Check EGR valve. Check for leaking valve, adapter and feed pipes.
L Check fuel quality. Fuel with wrong octane rating may cause driveability issues.
L During transportation of vehicle from assembly plant to dealership can involve as many as 60 ignition cycles while only driving 2-3 miles. This can result in fouled spark plugs, causing MIL to illuminates and DTC P0300 to set.

If DTC cannot be duplicated, reviewing scan tool FAILURE RECORDS data can be useful in determining mileage and frequency of DTC occurrence.

DTC P1312: ION SENSING MODULE SEC 2 LINE CIRCUIT FAULT
Diagnostic Aids

Intermittent problem may be caused by poor connections, misrouted harness, rubbed through wire insulation, broken wire inside insulation. Check for faulty connections at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, faulty terminal to wire connection. Check for wire harness damage. Using scan tool, observe appropriate scan tool display while moving related wire harness connectors and wire harnesses. A change in display will indicate location of fault. If DTC P1312 cannot be duplicated, reviewing scan tool FAILURE RECORDS data can be useful in determining mileage and frequency of DTC occurrence.

KHLow2008
Dec 29, 2012.
Thanks for your reply and sorry about taking so long to reply, but have been trying to figure out this problem. After replacing the 02 sensor on bank one sensor 1 and sensor on bank 2 sensor 1 The teck found that the wiring on the two banks had been reversed. He changed this and all of the codes cleared up. Now there is a code of P0420 and P0430 that will show up. The truck runs great with these codes showing. Is it possible that the wiring could also be reversed on these also and get this code.
This is a 2002 Rodeo with a V6 auto transm. With 4 wheel drive. It appears that the motor has been changed could this be a cause for the reverse wiring. Thans for the help.
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Tiny
Grady01
Jan 15, 2013.
The codes are for the catalytic converters and if there are any wiring fault, they would be wioth the HO2S. Unless the HO2S are not working efficiently, otherwise the problem would be with the catalytic converter.

KHLow2008
Jan 23, 2013.

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