Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Section 9A, Body Wiring System in Testing for Intermittent Conditions and Poor Connections.

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom :

The body control module (BCM) controls the A/T shift lock solenoid by providing battery voltage to the A/T shift lock solenoid. The BCM utilizes a smart driver to control the voltage supplied to the A/T shift lock solenoid. The smart driver monitors the voltage and current flow of the control circuit.

DTC B1000 33 : Special Memory Failure

DTC B1000 34 : ECM RAM Failure

DTC B1000 35 : ECM ROM Failure

DTC B1000 36 : ECM EEPROM Failure

The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

If this DTC is retrieved as a current DTC, replace the module that set the DTC.

Perform the Diagnostic Repair Verification after completing the repair. Refer to Section 9A, Body Wiring System.

Also, refer to the related module and the non-communicating module replacement,setup and programming.

The theft deterrent module compares its stored VIN value to the platforms body module that houses the vehicle identification number, if the values do not match this DTC sets.

The ignition is ON.

Perform the Diagnostic Repair Verification aftercompleting the diagnostic procedure.

The internal fault detection is handled inside the control module. No external circuits are involved.

The only requirements are voltage and ground.

The module has detected that the VIN is not programmed.

Program the VIN information to the body control module (BCM).

Turn the ignition OFF, wait several seconds and then turn the ignition ON.

Retrieve DTCs from the BCM. DTC B1016 should change to a history DTC.

Perform the Diagnostic Repair Verification after completing the repair. Refer to Section 9A, Body Wiring System.Also, refer to The related module and the non-communicating module replacement, setup and programming.

When learning a coded key, the immobilizer (RK3+) 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 immobilizer does not exit learn mode, B3031 will remain current and indicate a fault.

The vehicle theft deterrent system is in learn mode.

DTC B3031 will set any time the immobilizer enters learn mode.

The security indicator will illuminate.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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 immobilizer (TPK3+). The immobilizer then compares this value to a value stored in memory. This stored value is the learned key code. If the value is correct, the immobilizer will send the start enable password via the serial data circuit to the engine control module (ECM). If either the transponders unique value or the calculation to the challenge is incorrect, the immobilizer will send the start disable password to the ECM.

Ignition is in the Accessory or Run position.

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

Vehicle starting will be disabled.

The security indicator will be illuminated.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.·

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 immobilizer (PK3+). The immobilizer then compares this value to a value stored in memory. This stored value is the learned key code. If the value is correct, the immobilizer will send the start enable password via the serial data circuit to the engine control module (ECM). If either the transponders unique value or the calculation to the challenge is incorrect, the immobilizer will send the start disable password to the ECM.

Ignition is in the Accessory or Run position.

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

Vehicle starting will be disabled.

The security indicator will be illuminated.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.·

When the immobilizer (PK3+) is in the learn coded key or learn more keys mode, the immobilizer checks the current key to ensure it has been configured as a proper vehicle key.

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

The security indicator will be illuminated.

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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.·

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 immobilizer (PK3+). The immobilizer then compares this value to a value stored in memory. This stored value is the learned key code. If the value is correct, the immobilizer sends the start enable password via the serial data circuit to the engine control module (ECM). If either the transponders unique value or the calculation to the challenge is incorrect, the immobilizer will send the start disable password to the ECM.

Vehicle starting will be disabled.

The security indicator will be illuminated.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Substitution Detection has not passed for the vehicle.

The ignition is ON.

Perform the Diagnostic Repair Verification aftercompleting the diagnostic procedure.

Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.

The body control module (BCM) activates the serial data communication enable and the accessory wakeup serial data circuits by applying voltage when the ignition key is in ACC, ON or START. The serial data communication enable circuit wakes up the electronic brake control module (EBCM) for bus communication and the accessory wakeup serial data circuit wakes up the engine control module (ECM) and transmission control module (TCM).

A supervised periodic message that includes the transmitter module availability has not been received.

The module(s) is never signaled, therefore the specific subsystem(s) will not function.

Using the Diagnostic Aids above, determine the module that is not communicating that should be tested.

Ignition OFF, disconnect the harness connector of the module that is not communicating.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Refer to Section 9A, Body Wiring System. The related module and the non-communicating module replacement, setup and programming.

Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.

The body control module (BCM) activates the serial data communication enable and the accessory wakeup serial data circuits by applying voltage when the ignition key is in ACC, ON or START.

A supervised periodic message that includes the transmitter module availability has not been received.

The module(s) is never signaled, therefore the specific subsystem(s) will not function.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Refer to Section 9A, Body Wiring System.

When the correct number of learned master keys are not available to perform adding keys procedure the key coding procedure must be performed.

Important :

Turn ON the ignition with the engine OFF. The vehicle has now learned the new key.

From the scan main menu, select service programming system, then follow the instructions on the screen.

Use this procedure after replacing any of the following components :

From the scan main menu, select service programming system, then follow the instructions on the screen.

The content theft deterrent (CTD) system, when armed, is designed to deter vehicle content theft by pulsing the horns and exterior lamps for approximately 30 seconds when an unauthorized vehicle entry is detected. However, the CTD System does not affect engine starting.

An unauthorized entry can be any of the following with the CTD System armed :

The components of the system are :

Use the following procedure in order to arm the system :

The security indicator will illuminate steady when in the locked state.If the LOCK button is pressed after the vehicle doors have been closed, the open state will be bypassed and the system will transition directly to the locked state with the indicator on steady.

Locking the vehicle may be accomplished without arming the content theft deterrent (CTD) system by locking the vehicle using the manual door locks.

If system arming has been requested by the keyless entry transmitter, it must be disarmed.

To disarm the CTD system perform one of the following :

The following is a description of each component used in the content theft deterrent (CTD) system :

The CTD system is an internal function of the body control module (BCM) which utilizes serial data and various switch inputs to perform CTD functions.

When the BCM detects an unauthorized entry, it activates the horns and exterior lamps.

When the BCM detects an unauthorized entry, the BCM will first enter the warn-away mode. Warn-away will command short chips from the horn. If after 10 seconds the unauthorized entry still exists, the BCM will transition to the alarm mode. The horn and lamps will pulse for 30 seconds. Following the 30-second alarm period is a 10-second time-out. The system will then re-arm.

The CTD system uses the door ajar switches in the door jambs as one method to activate the alarm.

The BCM monitors all door ajar switches via a discrete input from each door ajar switch. If the BCM receives a ground signal from a door ajar switch when the CTD system is armed, the BCM activates the alarm.

Inputs

The BCM monitors the following inputs :

Outputs

The BCM controls the following :

The vehicle theft deterrent (VTD) 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 fuel enable 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. It is important to note that while it is referred to as the fuel enable/disable password, the vehicles starter may also be disabled, preventing engine cranking.

When the ECM receives the TDM fuel enable 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 VTD system are as follows :

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: battery voltage, ignition switched voltage and ground circuit. The theft deterrent control module uses the following outputs :

password exchange and 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, thetransponder 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 control module. The theft deterrent control module then compares this value to the learned key code stored in memory. The theft deterrent control module then performs one of the following functions :

When the engine control module (ECM) receives the theft deterrent module (TDM) fuel enable 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 :

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 vehicle theft deterrent (VTD) 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.

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 police fleet use.

The theft deterrent module (TDM) can command the clock 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 VTD system and when engine starting is disabled.