Mechanics

CHEVY , LOSE KEY FOB, START PROBLEM

1999 Chevrolet Blazer

Electrical problem
1999 Chevy Blazer 6 cyl Four Wheel Drive Automatic 153000 miles

Hi, I am from Czech republic, Europa. I have a problem with my Chevy. I lose my key fob, original key stay, and I have my Chevy in SECURITY mode. Is possible to disarm these mode manualy? I have car in mountains, my friend have TECH2, but its 500km.
I love these car, but in Europa is few of good mechanics. Thank you for answer. Vladimir
Avatar
Vladimir Cech
January 4, 2009.



PASSLOCK(tm) SYSTEM
When mechanical key turns Passlock(tm) lock cylinder, a Resistance Code (R-Code), is created by a rotating magnet turning past a stationary Hall Effect sensor. R-Code is sent to the BCM. The BCM determines validity of R-Code within a preset time window, then sends a coded password over the class 2 serial data line to the Powertrain Control Module (PCM)/Vehicle Control Module (VCM), which then allows fuel injectors to operate normally.
If BCM sends a password that is different than learned password in PCM/VCM, the PCM/VCM will enter no start mode. During this mode, fuel injectors are shut off for 10 minutes and SECURITY indicator light will stay on. Engine may crank and temporarily start, but will soon stall due to fuel shut-off. If a large magnet is placed near Passlock(tm) sensor, a tamper signal will be sent to BCM. The system is continually self diagnosing certain functions. If a malfunction exists, system will store a Diagnostic Trouble Code (DTC). BCM does not illuminate Malfunction Indicator Light (MIL). If a Passlock(tm) DTC exists, BCM illuminates SECURITY indicator light.

PROGRAMMING
PASSLOCK(tm) AUTO LEARN PROCEDURE
NOTE: This procedure allows relearning of BCM or VCM/PCM learned data code after replacement of BCM, sensor or VCM/PCM. DTC B3031 will set when entering programming mode.

Turn ignition off. Replace failed component. With transmission in Park (A/T) or Neutral (M/T), momentarily turn ignition switch to START position (engine will not start), and then leave in RUN position. SECURITY indicator light will stay on for 10 minutes. After 10 minutes, when light turns off, turn ignition switch to OFF position for 5 seconds.
Repeat step 1 twice more. Auto learn procedure will be completed during next start attempt. If VCM/PCM was replaced, reprogram VCM/PCM. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
Using scan tool following scan tool manufacturer's instructions, check for DTCs. If Passlock(tm) DTCs exist, see SELF-DIAGNOSTIC SYSTEM. If engine performance-related DTCs exist, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. After repairs, check system operation. See DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.

Dave H
Jan 4, 2009.
Hi, thank you for answer, but so much information.
I turn key to possition for START engine when all light indicator is on and SECURITY in on too and I had wait for 10 min, but the SECURITY stay light and start is no possible. Please help me once more with your message or write me these more easy.

Thank you Vladimir

Tiny
Vladimir Cech
Jan 5, 2009.
PROGRAMMING
PASSLOCK(tm) AUTO LEARN PROCEDURE

Turn ignition off.

With transmission in Park (A/T) or Neutral (M/T),

momentarily turn ignition switch to START position crank over (engine will not start),

then leave in RUN position. (Key on ignition lights on) SECURITY indicator light will stay on for 10 minutes.

After 10 minutes, when light turns off, turn ignition switch to OFF position for 5 seconds.

Repeat steps twice more. (2 times more)

Auto learn procedure will be completed during next start attempt. (Retry to start ! Should now start)

Let me know?

Dave H
Jan 5, 2009.
Hi, problem.

After 20 minutes, light SECURITY stay. Its possible?
Vladimir

Tiny
Vladimir Cech
Jan 7, 2009.
If the light is staying ON constantly. There must be another fault or you are not using the correct key for the car. It is going to need plugging in to a computer to find out the fault !

Lets make sure your doing this correctly?

PROGRAMMING
PASSLOCK(tm) AUTO LEARN PROCEDURE

STEP 1) Turn ignition off. Put transmission in Park (A/T) or Neutral (M/T),

STEP 2) momentarily turn ignition switch to START position. TRY CRANKING FOR ONE SECOND

DO NOT TURN KEY BACK TO OFF POSITION

STEP 3) leave in RUN position. (Key on, ignition lights on) SECURITY indicator light will stay on for 10 minutes.

STEP 4) After 10 minutes, when light turns off, turn ignition switch to OFF position for 5 SECONDS

REPEAT STEPS 1 TO 4
THEN
REPEAT STEPS 1 TO 4
THEN
Auto learn procedure will be completed during next start attempt.

TRY TO START THE VEHICLE

If you are saying the light does not got out at anytime. Then the car needs the fault to be read by computer

Let me know !

Dave H
Jan 7, 2009.
My friend come with TECH 2. Is possible to disable PASSLOCK with TECH 2 and using another security system with remote start?

Tiny
Vladimir Cech
Jan 9, 2009.
You cannot just disable the passlock system. You will have to find out what the fault code is and rectify the fault !

BCM PROGRAMMING
NOTE: This procedure requires Techline terminal and associated equipment.

Ensure battery is fully charged. Ensure battery and lighter connectors are secure. Ensure DLC is accessible. Turn ignition on. Refer to Techline terminal and equipment user's instructions.
If BCM fails to program, check all BCM connections, check Techline terminal and equipment for latest software version. Retry programming. If BCM fails to program again, replace BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION. Clear DTCs after programming.
TROUBLE SHOOTING
PRELIMINARY INSPECTION
NOTE: If sensor, BCM, PCM or VCM are replaced, vehicle will not start until learn procedure is completed. See PROGRAMMING.

Check all fuses. Ensure all system connections are mated correctly. Using scan tool, check for engine performance-related DTCs. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
Check for broken or partially broken wires. Check for correct installation of aftermarket electronic equipment. Ensure all grounds are clean and tight.
If preliminary inspection does not locate area of fault, check on-board diagnostic system. See DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
SELF-DIAGNOSTIC SYSTEM
NOTE: The CTD system will not set Diagnostic Trouble Codes (DTC).

DIAGNOSTIC SYSTEM CHECK
CAUTION: When disconnecting BCM harness connectors, always disconnect Brown connector first, and reconnect last.

Turn ignition switch to RUN position. If SECURITY indicator light illuminates for 3 seconds, and then turns off, go to step 4. If SECURITY indicator light does not illuminate for 3 seconds, and then turn off, go to next step.
If SECURITY indicator light flashes, go to step 15. If SECURITY indicator light does not flash, go to next step.
Turn ignition switch to START position. If engine starts, go to step 15. If engine does not start, see SYMPTOM TESTS.
Turn ignition switch to START position. If engine starts, go to next step. If engine does not start, go to step 8.
If SECURITY indicator light is on, or customer reports light is on during normal driving conditions, go to next step. If SECURITY indicator light is not on while engine is running, system is okay.
Using scan tool, attempt to communicate with BCM. If communication exists, go to next step. If communication does not exist, go to step 17.
Check for current Passlock(tm) or engine performance-related DTCs. If any DTCs exist, diagnose and repair as necessary. For engine performance-related DTCs, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. For Passlock(tm) DTCs, see DIAGNOSTIC TROUBLE CODE INDEX table. If no DTCs exist, diagnose and repair instrument cluster. See appropriate ANALOG INSTRUMENT PANELS article.
If SECURITY indicator light is off, go to next step. If SECURITY indicator light is on, go to step 12.
If engine cranked normally, go to next step. If engine did not crank normally, go to step 11.
Check fuel delivery. See appropriate BASIC DIAGNOSTIC PROCEDURES article in ENGINE PERFORMANCE.
Check starting system. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
If SECURITY indicator light is on steady, go to next step. If SECURITY indicator light is not on steady, go to step 15.
Check for current Passlock(tm) DTCs. If no DTCs exist go to next step. If any DTCs exist, see DIAGNOSTIC TROUBLE CODE INDEX table.
Diagnose and repair instrument cluster. See appropriate ANALOG INSTRUMENT PANELS article.
Check for current Passlock(tm) or engine-related DTCs. If any DTCs exist, diagnose and repair as necessary. For engine-related DTCs, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. For Passlock(tm) DTCs, see DIAGNOSTIC TROUBLE CODE INDEX table. If no DTCs exist, diagnose and repair instrument cluster. See appropriate ANALOG INSTRUMENT PANELS article.
Using scan tool, check for current Passlock(tm) DTCs in BCM. If communication does not exist, go to next step. If any DTCs exist, see DIAGNOSTIC TROUBLE CODE INDEX table.
Repair class 2 serial data line communications. See DATA LINK CONNECTORS article in WIRING DIAGRAMS. After repairs, clear DTCs.
DIAGNOSTIC TROUBLE CODE INDEX
DTC (1) Description
B2947 Passlock(tm) Sensor Power Circuit Low
B2948 Passlock(tm) Sensor Power Circuit High
B2957 Passlock(tm) Sensor Data Circuit Low
B2958 Passlock(tm) Sensor Data Circuit High
B2960 Passlock(tm) Sensor Data Incorrect But Valid
B3031 Controller In Learn Mode
B3033 System Indicates Tamper
U1016 (2) Loss of Class 2 Communication With VCM/PCM
U1255 (2) Class 2 Communication Malfunction
U1301 (2) Class 2 Data Link High
(1)See DIAGNOSTIC TESTS.
(2)For diagnosis and repair, see DATA LINK CONNECTORS article in WIRING DIAGRAMS.

Dave H
Jan 10, 2009.
I have original key to my VIN, but the main computer was changed and VIN in main computer is other. And in shop need the number VIN for original key. Is possible to take the VIN from main computer when is passlock ON? I have here Equus Innova OBD II CODE READERS 3100C and computer. Maybe some PC software with function like TECHII in computer with OBD2 cable?

Tiny
Vladimir Cech
May 8, 2009.
Hello.

The replacement cars computer should still recognise the key with the reprogramme procedure ! If it does not you will need a Techline scanner or Techline software on a computer and an OBDII cable to link computer and vehicle together !

BCM PROGRAMMING
NOTE: This procedure requires Techline terminal and associated equipment. Or Techline software, computer and DLC.

Ensure battery is fully charged. Ensure battery and lighter connectors are secure. Ensure DLC is accessible. Turn ignition on. Refer to Techline terminal and equipment user's instructions.
If BCM fails to program, check all BCM connections, check Techline terminal and equipment for latest software version. Retry programming. If BCM fails to program again, replace BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION. Clear DTCs after programming.

PASSLOCK(tm) SYSTEM
When mechanical key turns Passlock(tm) lock cylinder, a Resistance Code (R-Code), is created by a rotating magnet turning past a stationary Hall Effect sensor. R-Code is sent to the BCM. The BCM determines validity of R-Code within a preset time window, then sends a coded password over the class 2 serial data line to the Powertrain Control Module (PCM)/Vehicle Control Module (VCM), which then allows fuel injectors to operate normally.
If BCM sends a password that is different than learned password in PCM/VCM, the PCM/VCM will enter no start mode. During this mode, fuel injectors are shut off for 10 minutes and SECURITY indicator light will stay on. Engine may crank and temporarily start, but will soon stall due to fuel shut-off. If a large magnet is placed near Passlock(tm) sensor, a tamper signal will be sent to BCM. The system is continually self diagnosing certain functions. If a malfunction exists, system will store a Diagnostic Trouble Code (DTC). BCM does not illuminate Malfunction Indicator Light (MIL). If a Passlock(tm) DTC exists, BCM illuminates SECURITY indicator light.

PASSLOCK(tm) AUTO LEARN PROCEDURE
NOTE: This procedure allows relearning of BCM or VCM/PCM learned data code after replacement of BCM, sensor or VCM/PCM. DTC B3031 will set when entering programming mode.

Turn ignition off. Replace failed component. With transmission in Park (A/T) or Neutral (M/T), momentarily turn ignition switch to START position (engine will not start), and then leave in RUN position. SECURITY indicator light will stay on for 10 minutes. After 10 minutes, when light turns off, turn ignition switch to OFF position for 5 seconds.
Repeat step 1 twice more. Auto learn procedure will be completed during next start attempt. If VCM/PCM was replaced, reprogram VCM/PCM. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
Using scan tool following scan tool manufacturer's instructions, check for DTCs. If Passlock(tm) DTCs exist, see SELF-DIAGNOSTIC SYSTEM. If engine performance-related DTCs exist, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. After repairs, check system operation. See DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.

Dave H
May 9, 2009.