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Immobilizer System: Other Chevrolet Tahoe III

Door Locks & Anti-Theft Systems 1 illustration ~3720 words

Reference Information

Schematic Reference

  1. «Immobilizer Schematics»(ref-364537-S03114159102010063000000)
  2. «Remote Function Schematics»(ref-364503-S42097097192010063000000)

Connector End View Reference

Component Connector End Views

Description and Operation

Keyless Entry System Description and Operation (Without Accessory 2 Way Remote) or Keyless Entry System Description and Operation (With Accessory 2 Way Remote)

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool BCM Hood Open Switch and Hood Closed Switch parameters. With the hood open, the Hood Open Switch parameter should read Active and the Hood Closed Switch parameter should read Inactive. With the hood closed, the Hood Open Switch parameter should read Inactive and the Hood Closed Switch parameter should read Active.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Hood Primary and Secondary Latch Replacement»(ref-364470-S03144980182010063000000)
  2. «Control Module References»(ref-364489-S22329914082010063000000) for BCM replacement, programming and setup

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

  1. With a master vehicle key, turn the ignition ON.
  2. Observe the security indicator. After approximately 10 minutes, the indicator will turn off.
  3. Turn the ignition OFF and wait 5 seconds.
  4. Repeat steps 2-4 two more times for a total of 3 cycles or 30 minutes.
  5. With a master vehicle key, turn the ignition ON. The start disable will now be cleared.
  6. Using the Red Emergency Button, notify the advisor that the Ignition Block on the vehicle has been cleared and to update the account status.

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTWhen performing the 10-Minute Vehicle Key Relearn Procedure, all keys not learned at that time will be erased and not be recognized. Perform the Adding Keys procedure on all keys or instruct the customer how to perform the Adding Keys procedure should all keys not be present at the time of repair.
  1. Verify DTC B3055 is not set. If the DTC is set, refer to «DTC B3055»(ref-364537-S19373707852010063000000) .
  2. Verify the scan tool TDM Learn Coded Key parameter displays Yes. If not the specified value, perform the 10 Minute Vehicle Key Relearn procedure. Refer to «Replacing Keys (Canada)»(ref-364537-S06460008962010063000000) or «Replacing Keys (North America except Canada)»(ref-364537-S09593069012010063000000) .
  3. Perform the 10 Minute Vehicle Key Relearn procedure. Refer to «Replacing Keys (Canada)»(ref-364537-S06460008962010063000000) or «Replacing Keys (North America except Canada)»(ref-364537-S09593069012010063000000) . The TDM should exit the learn coded key state and DTC B3031 should clear. If the TDM does not exit the learn coded key state after the programming attempt, replace the TDM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TDM replacement, setup and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTWhen using this diagnostic, more than one vehicle key is required to ensure proper diagnosis. If more than one key is not available at the time of service, contact the customer and ask if any other keys can be provided for service. If unavailable, a new second key can be created.
  1. Inspect all available vehicle keys that they are correct vehicle keys. If not a correct vehicle key, replace the key.
  2. While viewing the scan tool TDM Transponder Key parameter, turn ON the ignition with each of the available vehicle keys. The parameter should read Present with all available keys. If only one key results in the parameter reading Not Present, replace the appropriate key. If all available keys result in the parameter reading Not Present, replace the TDM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Replacing Keys (Canada)»(ref-364537-S06460008962010063000000) or «Replacing Keys (North America except Canada)»(ref-364537-S09593069012010063000000)
  2. «Control Module References»(ref-364489-S22329914082010063000000) for TDM replacement, setup, and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTWhen using this diagnostic, more than one vehicle key is required to ensure proper diagnosis. If more than one key is not available at the time of service, contact the customer and ask if any other keys can be provided for service. If unavailable, a new second key can be created.
  1. Perform the 10-Minute Vehicle Key Relearn procedure. Refer to «Replacing Keys (Canada)»(ref-364537-S06460008962010063000000) or «Replacing Keys (North America except Canada)»(ref-364537-S09593069012010063000000) .
  2. While viewing the scan tool TDM Valid Key parameter, turn ON the ignition with each of the available vehicle keys. The parameter should read Yes with all available keys. If not the specified value, replace the appropriate key.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Replacing Keys (Canada)»(ref-364537-S06460008962010063000000) or «Replacing Keys (North America except Canada)»(ref-364537-S09593069012010063000000)
  2. «Control Module References»(ref-364489-S22329914082010063000000) for TDM replacement, setup, and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

Replace the suspected inoperative or malfunctioning key. DTC B3935 should not reset and the vehicle should start.

  1. If the replacement key results in the resetting of DTC B3935, replace the TDM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Replacing Keys (Canada)»(ref-364537-S06460008962010063000000) or «Replacing Keys (North America except Canada)»(ref-364537-S09593069012010063000000)
  2. «Control Module References»(ref-364489-S22329914082010063000000) for theft deterrent module replacement, setup, and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTWhen using this diagnostic, more than one vehicle key is required to ensure proper diagnosis. If more than one key is not available at the time of service, contact the customer and ask if any other keys can be provided for service. If unavailable, a new second key can be created.

While viewing DTCs with a scan tool, attempt to start the vehicle using all of the available keys. The vehicle should start with all available keys.

  1. If any key results in inoperative starting and DTC B3976 is set, replace the appropriate key.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Replacing Keys (Canada) or Replacing Keys (North America except Canada)

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

  1. Verify the following BCM DTCs are not present: U1814 U2099 B1428 B1370 B1380 B1440 B1441 If any listed DTC is present, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-364486-S07394808542010063000000) to diagnose that DTC prior to this diagnostic.
  2. Perform the 10-Minute Immobilizer Relearn procedure. Refer to «Immobilizer System Component Programming»(ref-364537-S10971487772010063000000) . The ECM should successfully complete the password learn and the vehicle should start. If the ECM does not complete the learn or vehicle starting remains disabled, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTBecause of normal system communications between the TDM and ECM, any theft deterrent B-codes must be diagnosed prior to the diagnosis of P-codes. DTC P0633 will clear upon a successful engine start. Any malfunction that will cause a no-start condition will prevent DTC P0633 from clearing. Prior to diagnosing DTC P0633, ensure that all power moding and engine control systems are operating properly and all conditions that may cause a no-start have been corrected.
  1. Ignition in the CRANK position, verify the scan tool Ignition Run/Crank parameter is Active. If not the specified value, refer to «Power Mode Mismatch»(ref-364488-S28718885792010063000000) .
  2. Perform the 10-Minute Immobilizer Relearn procedure. Refer to «Immobilizer System Component Programming»(ref-364537-S10971487772010063000000) . The ECM should successfully complete the password learn and the vehicle should start. If the ECM does not complete the learn or vehicle starting remains disabled, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

Description and Operation

Remote Vehicle Speed Limiting Description and Operation (Stolen Vehicle Slow-Down)

Scan Tool Reference

Control Module References for scan tool information

If the DTC is set, perform the Stolen Vehicle Slow-Down Clear with a scan tool. If the DTC resets, replace the VCIM. If the DTC resets again, replace the ECM.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for VCIM and ECM replacement, setup, and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTBecause of normal system communications between the TDM and ECM, any theft deterrent B-codes must be diagnosed prior to the diagnosis of P-codes.

Perform the 10-Minute Immobilizer Relearn procedure. Refer to Immobilizer System Component Programming . The ECM should successfully complete the password learn and the vehicle should start.

  1. If the ECM does not complete the learn or vehicle starting remains disabled, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTBecause of normal system communications between the TDM and ECM, any theft deterrent B-codes must be diagnosed prior to the diagnosis of P-codes.

Perform the 10-Minute Immobilizer Relearn procedure. Refer to Immobilizer System Component Programming . The ECM should successfully complete the password learn and the vehicle should start.

  1. If the ECM does not complete the learn or vehicle starting remains disabled, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup and programming

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Keyless Entry System Description and Operation (Without Accessory 2 Way Remote) or Keyless Entry System Description and Operation (With Accessory 2 Way Remote)

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool ECM Hood Position parameter. With the hood open, the Hood Position parameter should read Open. With the hood closed, the Hood Position parameter should read Closed.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Hood Primary and Secondary Latch Replacement»(ref-364470-S03144980182010063000000)
  2. «Control Module References»(ref-364489-S22329914082010063000000) for ECM replacement, programming and setup

Symptoms - Immobilizer

IMPORTANTThe following steps must be completed before using the symptom tables.
  1. Perform the «Diagnostic System Check - Vehicle»(ref-364486-S08087544882010063000000) before using the symptom tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data links.
  2. Review the system operation in order to familiarize yourself with the system functions. Refer to «Immobilizer Description and Operation»(ref-364537-S39439383272010063000000) .

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Verification

Verify the vehicle is not in an OnStar initiated Stolen Vehicle Slow-Down mode. Look for a Reduced Engine Power message.

  1. If in the Stolen Vehicle Slow-Down mode, perform the OnStar vehicle interface communication module (VCIM) Stolen Vehicle Slow-Down Clear with a scan tool. After performing the clear event procedure, press the Blue OnStar® button to inform the advisor that you need to be transferred to the Stolen Vehicle team to have the vehicle account updated.

Schematic Reference

  1. «Immobilizer Schematics»(ref-364537-S03114159102010063000000)
  2. «Remote Function Schematics»(ref-364503-S42097097192010063000000)

Connector End View Reference

Component Connector End Views

Description and Operation

Keyless Entry System Description and Operation (Without Accessory 2 Way Remote) or Keyless Entry System Description and Operation (With Accessory 2 Way Remote)

Electrical Information Reference

  1. «Circuit Testing»(ref-364488-S04114729552010063000000)
  2. «Connector Repairs»(ref-364488-S23771656832010063000000)
  3. «Testing for Intermittent Conditions and Poor Connections»(ref-364488-S16423338542010063000000)
  4. «Wiring Repairs»(ref-364488-S17530456672010063000000)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool BCM Hood Open Switch and Hood Closed Switch parameters. With the hood open, the Hood Open Switch parameter should read Active and the Hood Closed Switch parameter should read Inactive. With the hood closed, the Hood Open Switch parameter should read Inactive and the Hood Closed Switch parameter should read Active.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Hood Primary and Secondary Latch Replacement»(ref-364470-S03144980182010063000000)
  2. «Control Module References»(ref-364489-S22329914082010063000000) for BCM or instrument cluster replacement, programming and setup

Scheme 43

Scheme 43: Theft Deterrent Module Replacement
Scheme 43: Theft Deterrent Module Replacement
CalloutComponent Name
Preliminary Procedure Disable the SIR. Refer to SIR Disabling and Enabling . Remove the ignition cylinder. Refer to Ignition Lock Cylinder Replacement . Program the theft deterrent control module after replacement. Refer to Control Module References .
1Theft Deterrent Module Assembly Tip: Pull out away from lock cylinder case and disconnect the electrical connector.

10-Minute Immobilizer Relearn

This 10-minute relearn procedure will relearn the prerelease password and the challenge/response data between the theft deterrent module (TDM) and the engine control module (ECM).

  1. Connect a scan tool to the vehicle in the pass-thru arrangement.
  2. Turn ON the ignition, with the engine OFF.
  3. Ensure that all power consuming devices are turned OFF on the vehicle.
  4. On the Techline Terminal, select Service Programming System and follow the Techline Terminal on-screen instructions, using the Pass-Thru method. Ensure the correct programming selection is chosen based on component being replaced or programmed. For this procedure, go to the V.T.D. Vehicle Theft Deterrent Learn menu and choose the Vehicle Theft Deterrent Learn, ECM, or PK3 Replaced selection.
  5. At this point the scan tool must remain connected for the duration of the 10-minute relearn procedure.
  6. Observe the scan tool, after approximately 10 minutes the scan tool will display "Programming Successful, Turn OFF Ignition". The vehicle is now ready to relearn the key information and/or the passwords on the next ignition switch transition from OFF to CRANK.
  7. Turn OFF the ignition and wait 2 minutes.
  8. With a master vehicle key, turn the ignition to the RUN position for 15 seconds, then start the vehicle. The TDM and ECM have now relearned the pre-release password and the challenge/response data.
  9. With a scan tool, clear any DTCs.

Adding Keys

IMPORTANTTo initiate, this procedures requires that a learned master key be available. A total of 10 keys may be programmed to a single vehicle. This procedure adds keys only. The procedure does not erase previously learned keys. The keys to be learned must duplicate the mechanical cut of the current key. If more than one valet key is to be learned, immediately precede each valet key with a learned master key.
  1. With a previously learned master key, turn ON the ignition, with the engine OFF.
  2. Turn OFF the ignition and remove the key.
  3. Within 10 seconds of turning OFF the ignition, insert the key to be learned and turn ON the ignition. The vehicle has now learned the new key.

10-Minute Vehicle Key Relearn

IMPORTANTThis procedure will only relearn the vehicle keys. This procedure will not learn the immobilizer prerelease password or the challenge/response data. Do not use this procedure as a substitute for a 10-minute relearn when replacing or reprogramming a theft deterrent module (TDM) or engine control module (ECM). Doing so will result in a failure to learn the pre-release password and/or the challenge/response data.

This 10-minute learn procedure should be used when all vehicle keys are desired to be replaced or reprogrammed. This procedure will erase all previously learned vehicle keys from the TDM. Once the 10-minute learn procedure has been completed, any remaining vehicle keys may be programmed using the Adding Keys procedure to ensure their continued functionality.

  1. Connect a scan tool to the vehicle in the pass-thru arrangement.
  2. Turn ON the ignition, with the engine OFF.
  3. Ensure that all power consuming devices are turned OFF on the vehicle.
  4. On the Techline Terminal, select Service Programming System and follow the Techline Terminal on-screen instructions, using the Pass-Thru method. Ensure the correct programming selection is chosen based on component being replaced or programmed. For this procedure, go to the VTD Vehicle Theft Deterrent Learn menu and choose the Vehicle Theft Deterrent Learn for Learning Replacement Keys selection.
  5. At this point the scan tool must remain connected for the duration of the 10-minute relearn procedure.
  6. Observe the scan tool, after approximately 10 minutes the scan tool will display "Programming Successful, Turn OFF Ignition". The vehicle is now ready to relearn the key information and/or the passwords on the next ignition switch transition from OFF to RUN.
  7. Turn OFF the ignition and wait 2 minutes.
  8. With a master vehicle key, turn the ignition to the RUN position for 15 seconds, then start the vehicle. The TDM has now learned the key transponder information.
  9. With a scan tool, clear any DTCs.
IMPORTANTThis procedure will only relearn the vehicle keys. This procedure will not learn the immobilizer prerelease password or the challenge/response data. Do not use this procedure as a substitute for a 10-minute relearn when replacing or reprogramming a theft deterrent module (TDM) or engine control module (ECM). Doing so will result in a failure to learn the pre-release password and/or the challenge/response data.

This 10-minute learn procedure should be used when all vehicle keys are desired to be replaced or reprogrammed. This procedure will erase all previously learned vehicle keys from the TDM. Once the 10-minute learn procedure has been completed, any remaining vehicle keys may be programmed using the Adding Keys procedure to ensure their continued functionality.

  1. Connect a scan tool to the vehicle in the pass-thru arrangement.
  2. Turn ON the ignition, with the engine OFF.
  3. Ensure that all power consuming devices are turned OFF on the vehicle.
  4. On the Techline Terminal, select Service Programming System and follow the Techline Terminal on-screen instructions, using the Legacy Pass-Thru method. Ensure the correct programming selection is chosen based on component being replaced or programmed. For this procedure, go to the V.T.D. Vehicle Theft Deterrent Learn menu and choose the Vehicle Theft Deterrent Learn for Learning Replacement Keys selection.
  5. At this point the scan tool must remain connected for the duration of the 10-minute relearn procedure.
  6. Observe the scan tool, after approximately 10 minutes the scan tool will display "Programming Successful, Turn OFF Ignition". The vehicle is now ready to relearn the key information and/or the passwords on the next ignition switch transition from OFF to CRANK.
  7. Turn OFF the ignition and wait 2 minutes.
  8. With a master vehicle key, turn the ignition to the RUN position for 15 seconds, then start the vehicle. The TDM has now learned the key transponder information.
  9. With a scan tool, clear any DTCs.

30-Minute Vehicle Key Relearn - Without RPO 5L5

IMPORTANTThis procedure will only relearn the vehicle keys. This procedure will not learn the immobilizer prerelease password or the challenge/response data. Do not use this procedure as a substitute for a 10-minute relearn when replacing or reprogramming a TDM or ECM. Doing so will result in a failure to learn the prerelease password and/or the challenge/response data.

This 30-minute learn procedure should be used when all vehicle keys are desired to be replaced or reprogrammed. This procedure will erase all previously learned vehicle keys from the TDM. Once the 30-minute learn procedure has been completed, any remaining vehicle keys may be programmed using the Adding Keys procedure to ensure their continued functionality.

  1. With an unlearned master vehicle key, turn ON the ignition, with the engine OFF.
  2. Observe the security indicator, after approximately 10 minutes the indicator will turn off.
  3. Turn OFF the ignition and wait 5 seconds.
  4. Repeat steps 1-3 two more times for a total of 3 cycles or 30 minutes.
  5. With a master vehicle key, start the vehicle. The vehicle has now learned the key transponder information.
  6. If additional keys are required to be learned, refer to «Adding Keys»(ref-364537-S39634433212010063000000) .
  7. With a scan tool, clear any DTCs.

6-Minute Vehicle Key Relearn - With RPO 5L5

IMPORTANTThis procedure will only relearn the vehicle keys. This procedure will not learn the immobilizer prerelease password or the challenge/response data. Do not use this procedure as a substitute for a 10-minute relearn when replacing or reprogramming a TDM or ECM. Doing so will result in a failure to learn the prerelease password and/or the challenge/response data.

This 6-minute learn procedure should be used when all vehicle keys are desired to be replaced or reprogrammed. This procedure will erase all previously learned vehicle keys from the TDM. Once the 6-minute learn procedure has been completed, any remaining vehicle keys may be programmed using the Adding Keys procedure to ensure their continued functionality.

  1. With an unlearned master vehicle key, turn ON the ignition, with the engine OFF.
  2. Observe the security indicator, after approximately 2 minutes the indicator will turn off.
  3. Turn OFF the ignition and wait 5 seconds.
  4. Repeat steps 1-3 two more times for a total of 3 cycles or 6 minutes.
  5. With a master vehicle key, start the vehicle. The vehicle has now learned the key transponder information.
  6. If additional keys are required to be learned, refer to «Adding Keys»(ref-364537-S39634433212010063000000) .
  7. With a scan tool, clear any DTCs.

Theft Deterrent Module (TDM)

Vehicles with steering column mounted ignition switches have the exciter integral with the theft deterrent module (TDM), which is located within the steering column. The TDM can learn up to 10 keys (transponder values).

The TDM uses the following inputs

  1. Battery voltage
  2. Ignition switched voltage
  3. Ground circuit

The theft deterrent control module uses the following outputs

  1. Password exchange
  2. Challenge/response with the engine control module (ECM)

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the TDM. The TDM then compares this value to the learned key code stored in memory. The TDM then performs one of the following functions

  1. If the transponder value matches the values stored in the TDM memory, the TDM will send the prerelease password to the ECM via the serial data circuit.
  2. If the transponders unique value does not match the value stored in the TDM, the TDM will send the fuel disable message to the ECM via the serial data circuit.
  3. If the TDM is unable to measure the ignition key transponder value, the TDM will not send any messages to the ECM.

Engine Control Module (ECM)

When the engine control module (ECM) receives the theft deterrent module (TDM) prerelease password, the ECM will challenge the password. The ECM sends this challenge back to the TDM via the serial data circuit. Both the ECM and TDM perform a calculation on this challenge. If the calculated response from the TDM equals the calculation performed by the ECM, the ECM will allow vehicle starting.

The ECM will disable vehicle starting if any of the following conditions occur

  1. The prerelease password is invalid.
  2. The fuel disable password is sent by the TDM.
  3. No passwords are received. There is no communication with the TDM.
  4. The TDM calculated response to the challenge does not equal the calculation performed by the ECM.

The Ignition Key (Transponder)

The ignition key for PassKey III+ (PK3+) equipped vehicles is a standard ignition key with a transponder located in the plastic head of the key. The transponder value is fixed and unable to be changed. The immobilizer system uses the ignition key transponder value to determine if a valid ignition key is being used to start the vehicle. There are approximately 3 trillion possible transponder values. There are no visible electrical contacts. The keys are identified by + symbol in a circle stamped into the steel shank of the key. The immobilizer system use the following types of ignition keys

Master Keys

Master keys have a black plastic head for full access operation of the vehicle. Master keys may perform the following functions

  1. Start the vehicle.
  2. Lock/unlock all of the door locks and rear compartment.
  3. Lock/unlock all of the storage compartments.

Valet Keys

IMPORTANTValet keys are NOT standard equipment on all GM vehicle lines.

Valet keys have a gray plastic head and are for restricted operation of the vehicle. Valet keys may perform the following functions

  1. Start the vehicle.
  2. Lock/unlock all of the door locks.

Fleet Keys

IMPORTANTFleet keys are NOT standard equipment on all GM vehicle lines.

Fleets keys allow full access to the vehicle just as a master key would. However, unlike a master key which may only learn 10 keys to a particular vehicle, an unlimited number of fleet keys may be learned to the vehicle. Fleet keys are only used in vehicles configured for fleet use with RPO 6E2 or 6E8.

  1. Start the vehicle.
  2. Lock/unlock all of the door locks and rear compartment.
  3. Lock/unlock all of the storage compartments.

Security Indicator

The theft deterrent module (TDM) can command the instrument panel cluster (IPC) to illuminate the security indicator only when the ignition key is in the ON position. The TDM will command the security indicator be illuminated any time a fault is noted in the immobilizer system and when the engine starting is disabled.

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