Home ReviewsRefund
Home/Chevrolet/Express G2500/Chevrolet Express G2500 (2013-2013)/Repair manual/Door Locks & Anti-Theft Systems/Immobilizer System
Contents Wiring diagrams Section: Door Locks & Anti-Theft Systems All sections

Immobilizer System Chevrolet Express G2500

Door Locks & Anti-Theft Systems 2 illustrations ~7129 words

Scheme 12

Scheme 12: Immobilizer Wiring Schematics
Scheme 12: Immobilizer Wiring Schematics

Diagnostic Code Index

DTCDescription
DTC B302ADTC B302A 00 Telematic Requested Immobilization
DTC B3031DTC B3031 00 Security System Controller In Learn Mode
DTC B3055DTC B3055 00 No Transponder Modulation or No Transponder
DTC B3060DTC B3060 00 Unprogrammed Transponder Identification Code Received
DTC B3935DTC B3935 57 Transponder Authentication Error
DTC B3976DTC B3976 46 Unconfigured Transponder/Vehicle Configuration Not Programmed
DTC P0513DTC P0513 Theft Deterrent Key Incorrect
DTC P0633DTC P0633 Theft Deterrent Key Not Programmed
DTC P1629DTC P1629 Theft Deterrent Fuel Enable Signal Not Received
DTC P162BDTC P162B Remote Vehicle Speed Limiting Signal Message Counter Incorrect
DTC P1630DTC P1630 Theft Deterrent Learn Mode Active
DTC P1631DTC P1631 Theft Deterrent Fuel Enable Signal Not Correct

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

As part of the vehicle telematics enhanced services, a request may be sent to the theft deterrent module (TDM) to disable vehicle starting. If a valid message is received by the TDM requesting that starting be disabled, the start enable message will not be sent to the engine control module (ECM).

Conditions for Running the DTC

The TDM continuously monitors for this DTC.

Conditions for Setting the DTC

A start disable message has been received from the telematics module.

Action Taken When the DTC Sets

Vehicle starting will be suspended and the security indicator will be illuminated.

Conditions for Clearing the DTC

  1. A current DTC will clear when the telematics start disable request is no longer received.
  2. A history DTC will clear after 100 ignition cycles in which the telematic start disable request is not seen.

Diagnostic Aids

  1. DTC B302A is only an indicator that a start disable request has been received from the vehicle telematics system and does not indicate a fault in the immobilizer or telematics system.
  2. To remove the start disable request, the vehicle account must be updated with the OnStar stolen vehicle team. This will require that a law enforcement agency or the customer contact OnStar to indicate that the vehicle has been successfully and safely recovered.
  3. If the OnStar system has been disabled or damage during a theft attempt, the system will not be able to communicate and the start disable request will not be removed. OnStar must be functioning properly for the start disable request to be removed.

Reference Information

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Verify the OnStar system is not damaged and is functioning properly with no DTCs set. If the OnStar system is damaged, inoperative, or any OnStar DTCs are set, these concerns must be corrected before the start disable can be removed.
  2. Press the blue OnStar button and ask the advisor to be transferred to the stolen vehicle team to verify the vehicle account has been updated.
  3. Very that OnStar is aware the vehicle has been recovered and that the vehicle account has been updated as such. If OnStar has not been notified that the vehicle has been recovered, contact the customer and advise them that for security purposes, they must contact OnStar and the law enforcement agency to update the vehicle account.
  4. After the vehicle account has been updated and the start disable request has been removed, DTC B302A will transition to a history DTC. Clear the history DTC.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When learning a coded key, the theft deterrent module (TDM) is placed in learn mode. DTC B3031 will set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the coded key is learned, learn mode will be exited and the DTC cleared. If the TDM does not exit learn mode, B3031 will remain current and indicate a fault.

The immobilizer system is the learn coded keys state.

DTC B3031 will set any time the TDM enters the learn coded keys state.

The security indicator will illuminate.

  1. A current DTC B3031 will be cleared upon the successful exit of learn mode.
  2. A history DTC will be cleared after 100 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

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»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) .
  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)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , «Replacing Keys (North America except Canada)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) .
  3. Perform the 10 Minute Vehicle Key Relearn procedure. Refer to «Replacing Keys (Canada)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , «Replacing Keys (North America except Canada)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) . 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.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TDM replacement, setup and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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 theft deterrent module (TDM). The TDM then compares this value to a value stored in memory. This stored value is the learned key code. If the value is correct, the TDM will send the prerelease password via the serial data circuit to the engine control module (ECM). If the learned key code does not match or a transponder value is not received, the TDM will send the start disable password to the ECM.

Ignition is in the Accessory or Run position.

The TDM is unable to measure the ignition key transponder value.

  1. Vehicle starting will be disabled.
  2. The security indicator will be illuminated.
  1. A current DTC will be cleared when the TDM detects a valid transponder value from the ignition key.
  2. A history DTC will be cleared after 100 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

In some instances, RF devices attached to a keychain or otherwise in close proximity of the ignition cylinder may cause interference in the immobilizer system and lead to a no-start condition. Some common RF devices that may be attached to a keychain are Speedpass gas station payment device, swipe devices used to gain access locked gates or 24-hour gyms, or other "smart" keys.

These RF devices interfere with the communication between the transponder located in the key and the TDM. The immobilizer systems operates at a frequency of 125 kHz. RF devices that operate in the 120 to 135 kHz range, or a multiplier of these frequencies, are most likely to cause interference. If interference occurs, DTC B3055, B3060, or B3935 may be set.

If interference is suspected, removed the suspect device from the keychain and attempt to start the vehicle. If vehicle starting occurs with the device removed, instruct the customer to remove the device from the keychain to prevent further occurrences. It may also be necessary to inspect all of the customers keychains if the concern is intermittent and doesn't occur with every key.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

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. Interference from an RF device located on the keychain may cause this DTC to set. Remove any RF devices from the keychain before proceeding with the diagnostic.
  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)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , «Replacing Keys (North America except Canada)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system)
  2. «Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for TDM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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 theft deterrent module (TDM). The TDM then compares this value to a value stored in memory. This stored value is the learned key code. If the value is correct, the TDM will send the prerelease password via the serial data circuit to the engine control module (ECM). If the transponder value does not match the learned key code or a transponder value is not received, the TDM will send the start disable password to the ECM.

Ignition is in the Accessory or Run position.

The transponder value measured by the TDM is incorrect or not learned to the vehicle.

  1. Vehicle starting will be disabled.
  2. The security indicator will be illuminated.
  3. The security indicator will flash (Canada only).
  1. A current DTC will be cleared when the TDM detects a valid transponder value from the ignition key.
  2. A history DTC will be cleared after 100 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

In some instances, RF devices attached to a keychain or otherwise in close proximity of the ignition cylinder may cause interference in the immobilizer system and lead to a no-start condition. Some common RF devices that may be attached to a keychain are Speedpass gas station payment device, swipe devices used to gain access locked gates or 24-hour gyms, or other "smart" keys.

These RF devices interfere with the communication between the transponder located in the key and the TDM. The immobilizer systems operates at a frequency of 125 kHz. RF devices that operate in the 120 to 135 kHz range, or a multiplier of these frequencies, are most likely to cause interference. If interference occurs, DTC B3055, B3060, or B3935 may be set.

If interference is suspected, removed the suspect device from the keychain and attempt to start the vehicle. If vehicle starting occurs with the device removed, instruct the customer to remove the device from the keychain to prevent further occurrences. It may also be necessary to inspect all of the customers keychains if the concern is intermittent and doesn't occur with every key.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

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. Interference from an RF device located on the keychain may cause this DTC to set. Remove any RF devices from the keychain before proceeding with the diagnostic.
  1. Perform the 10-Minute Vehicle Key Relearn procedure. Refer to «Replacing Keys (Canada)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , «Replacing Keys (North America except Canada)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) .
  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)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , «Replacing Keys (North America except Canada)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system)
  2. «Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for TDM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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 theft deterrent module (TDM). The TDM then compares this value to a value stored in memory. This stored value is the learned key code. If the value is correct, the TDM will send the prerelease password via the serial data circuit to the engine control module (ECM). If the transponder value does not match the learned key code or a transponder value is not received, the TDM will send the start disable password to the ECM.

  1. Ignition is in the Accessory or Run position.
  2. A valid transponder value has been read.
  1. The transponder value is valid and matches the value stored in the TDM memory.
  2. The transponder calculation to the challenge from the TDM does not match the TDM calculation.
  1. Vehicle starting will be disabled.
  2. The security indicator will be illuminated.
  1. A current DTC will be cleared when a valid transponder value has been read and authenticated.
  2. A history DTC will be cleared after 100 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

In some instances, RF devices attached to a keychain or otherwise in close proximity of the ignition cylinder may cause interference in the immobilizer system and lead to a no-start condition. Some common RF devices that may be attached to a keychain are Speedpass gas station payment device, swipe devices used to gain access locked gates or 24-hour gyms, or other "smart" keys.

These RF devices interfere with the communication between the transponder located in the key and the TDM. The immobilizer systems operates at a frequency of 125 kHz. RF devices that operate in the 120 to 135 kHz range, or a multiplier of these frequencies, are most likely to cause interference. If interference occurs, DTC B3055, B3060, or B3935 may be set.

If interference is suspected, removed the suspect device from the keychain and attempt to start the vehicle. If vehicle starting occurs with the device removed, instruct the customer to remove the device from the keychain to prevent further occurrences. It may also be necessary to inspect all of the customers keychains if the concern is intermittent and doesn't occur with every key.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTInterference from an RF device located on the keychain may cause this DTC to set. Remove any RF devices from the keychain before proceeding with the diagnostic.

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)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , «Replacing Keys (North America except Canada)»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system)
  2. «Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for theft deterrent module replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the theft deterrent module (TDM) is in the learn coded key state, the TDM checks the current key to ensure it has been configured as a proper vehicle key.

  1. Ignition is in the Accessory or Run position.
  2. The TDM is in the learn coded key state.

The TDM has determined the current key is not configured as a proper vehicle key.

  1. The security indicator will be illuminated.
  2. Vehicle starting will be disabled.
  1. A current DTC will be cleared when the TDM detects a properly configured vehicle key.
  2. A history DTC will be cleared after 100 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

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.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The theft deterrent module (TDM) sends the prerelease password to the engine control module (ECM) via the serial data circuit. The ECM then sends a challenge to the TDM. 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.

Ignition is in the ACCESSORY or RUN position.

The calculated response from the TDM does not equal the calculation performed by the ECM.

  1. The security indicator will illuminate.
  2. Vehicle starting will be disabled.
  1. A current DTC P0513 will be cleared when a valid calculation is received.
  2. A history DTC will be cleared after 40 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

The "key" referenced in the DTC descriptor does not refer to the vehicle key. In this case, "key" is referring to the challenge response.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

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»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) to diagnose that DTC prior to this diagnostic.
  2. Perform the 10-Minute Immobilizer Relearn procedure. Refer to «Immobilizer System Component Programming»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) . 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

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When learning the prerelease password, as well as the challenge and response sequence, the engine control module (ECM) is placed in learn mode. DTC P0633 will set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the password and challenge/response are learned, learn mode will be exited when the engine is successfully started. If the ECM does not exit learn mode, P0633 will remain current and indicate a fault.

The ECM is in learn mode.

DTC P0633 will set any time the ECM enters learn mode.

The security indicator will illuminate.

  1. A current DTC P0633 will be cleared upon a successful engine start after exit of learn mode.
  2. A history DTC will be cleared after 100 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

The "key" referenced in the DTC descriptor does not refer to the vehicle key. In this case, "key" is referring to the challenge response.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

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. Do not replace the ECM. Replacing the ECM will not correct the no-start condition.
  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»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures) .
  2. Perform the 10-Minute Immobilizer Relearn procedure. Refer to «Immobilizer System Component Programming»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) . 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, an undiagnosed no-start condition exists. Refer to the appropriate subsection and diagnostic to correct the no-start condition.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The theft deterrent module (TDM) sends the prerelease password to the engine control module (ECM) via the serial data circuit. The ECM then sends a challenge to the TDM. 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.

  1. Ignition is in the ACCESSORY or RUN position.
  2. The ECM is not in learn mode.

The ECM receives does not receive the challenge response from the TDM within the required amount of time.

The security indicator will illuminate.

  1. A current DTC P1629 will be cleared when a challenge response is received.
  2. A history DTC will be cleared after 40 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

DTC P1629 is an indicator that the challenge/response was not received within the required time. This does not necessarily indicate a fault is present with the TDM or ECM. Factors such as a long engine crank, a delay in the serial data communication, or B-codes set in the TDM will cause DTC P1629 to set. This DTC should not be used as a fault indicator, but rather as a symptom to assist in the diagnosis of these other systems.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When a remote slow-down request is sent from OnStar, the vehicle communication interface module sends a serial data message to the engine control module (ECM) indicating that reduced vehicle speed has been requested. Once the request is active, the ECM begins reducing engine torque to match requested vehicle speed and the REDUCED ENGINE POWER message is displayed.

  1. The engine run time is greater than 5 seconds.
  2. A remote slow-down request is sent from OnStar
  1. The VIN embedded in the slow-down request does not match the VIN stored in the ECM.
  2. The rolling code counter embedded in the slow-down request does not increment for ten consecutive messages.
  1. ECM ignores all reduced vehicle speed request messages from the vehicle communication interface module.
  2. The ECM stores DTC P162B in history.
  1. The condition responsible for setting the DTC no longer exists.
  2. A history DTC will clear after 40 malfunction-free ignition cycles have occurred.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Perform the scan tool Stolen Vehicle Slow-Down Clear. Verify DTC P162B is not set.

  1. If the DTC is set, replace the vehicle communication interface module and retest. If the DTC sets again, replace the ECM.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for vehicle communication interface module and ECM replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When replacing a theft deterrent module (TDM), the engine control module (ECM) must learn the new start enable password from the replacement TDM. If the ECM is replaced with a service replacement part, it is in a functional state to automatically learn the vehicle start enable password. If the TDM is replaced, the ECM must be placed in learn mode so it can learn the new TDM password. This DTC indicates the ECM is in a functional state to learn the TDM start enable password.

The ECM is in learn mode.

DTC P1630 will set any time the ECM enters learn mode.

The security indicator will illuminate.

  1. A current DTC will be cleared upon a successful engine start after exit of learn mode.
  2. A history DTC will be cleared after 100 malfunction-free ignition cycles.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

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

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The theft deterrent module (TDM) sends the prerelease password to the engine control module (ECM) via the serial data circuit. The ECM then sends a challenge to the TDM. 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.

Ignition is in the ACCESSORY or RUN position.

The ECM receives an incorrect prerelease password from the TDM.

  1. The security indicator will illuminate.
  2. Vehicle starting will be disabled.
  1. A current DTC P1631 will be when a correct fuel enable password is received.
  2. A history DTC will be cleared after 40 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

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

Symptoms - Immobilizer

IMPORTANTThe following steps must be completed before using the symptom tables.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) 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»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system__immobilizer-description-and-operation) .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the systems. Refer to «Checking Aftermarket Accessories»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

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

Symptom List

Refer to OnStar Stolen Vehicle Slowdown Active to diagnose the symptom.

Note. This procedure is not used in Brazil.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When a remote slow-down request is sent from OnStar, the vehicle communication interface module sends a serial data message to the engine control module (ECM) indicating that reduced vehicle speed has been requested. Once the request is active, the ECM begins reducing engine torque to match requested vehicle speed and the REDUCED ENGINE POWER message is displayed.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the vehicle is not in the OnStar initiated Stolen Vehicle Slowdown mode. Verify the scan tool ECM Reduced Engine Power History parameter is not Spd Limit Active.

  1. If the parameter is Spd Limit Active, perform the scan tool VCIM Stolen Vehicle Slowdown Clear. When the Stolen Vehicle Slowdown Clear is complete, press the blue OnStar button and inform the advisor that you need to be transferred to the stolen vehicle team to update the vehicle account.

Scheme 13

Scheme 13: Theft Deterrent Module Replacement
Scheme 13: Theft Deterrent Module Replacement
CalloutComponent Name
Preliminary Procedure Disable the SIR. Refer to SIR Disabling and Enabling . Remove the ignition lock cylinder. Refer to Ignition Lock Cylinder Replacement .
1Theft Deterrent Module Assembly Procedure Pull the theft deterrent module out away from lock cylinder case and disconnect the electrical connector. Refer to Control Module References for programing and setup of the theft deterrent control module after replacement..

Theft Deterrent Module Replacement

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 and to the TIS terminal.
  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 TIS terminal, select Service Programming System and follow the TIS terminal on-screen instructions. 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 vehicle must remain connected for the duration of the 10-minute relearn procedure.
  6. After approximately 10 minutes the TIS terminal 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. 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»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system__adding-keys) .
  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»(/chevrolet/express-g2500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system__adding-keys) .
  7. 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 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.

Immobilizer Description and Operation

The immobilizer system functions are provided by the theft deterrent module (TDM) and 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 coil surrounding the ignition lock cylinder. This exciter coil is part of the TDM. The energized transponder transmits a signal that contains its unique value, which is received by the TDM. The TDM then compares this value to a value stored in memory. If the values match, the TDM will send the prerelease password via the serial data circuit to the ECM. If the transponders unique value is incorrect, the TDM will send the fuel disable password to the ECM.

When the ECM receives the 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 components of the theft system are as follows

  1. TDM
  2. ECM
  3. Ignition key (Transponder)
  4. Security indicator

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)

Note. The ignition key will be stamped with a + or a + surrounded by a circle. This symbol only identifies the key as a PassKey III+ transponder key and is not a reliable way to determine if a particular key is the correct key for a vehicle. Service parts may have a different stamped symbol than the production part. The only way to determine the proper key for a vehicle is by referencing the parts catalog.

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 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.

Remote Vehicle Speed Limiting Description and Operation

Certain vehicles equipped with OnStar® now have an additional feature that allows for remote limiting of the vehicle's speed. This OnStar® feature is called Stolen Vehicle Slow-Down and is now part of the OnStar® Stolen Vehicle Assistance service. This feature, when used in conjunction with local law enforcement and strict guidelines at the OnStar® Call Center, will slow the vehicle by interacting with the engine control system.

When the engine control system receives a valid request from the OnStar® telematics communications interface module, it will enter into a reduced engine power/vehicle speed limiting mode, which will decelerate the vehicle. Once the request is active the engine control module begins reducing engine torque to match requested vehicle speed and a REDUCED ENGINE POWER indication is displayed. No DTCs will be set during this process.

More articles — Accessories & Equipment