Vehicle Theft Deterrent (VTD) Description and Operation

Passlock? System

The Passlock? System is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate or the ignition switch is operated while separated from the ignition lock cylinder case. If starting is attempted without authorization from the Passlock? System, the powertrain control module (PCM) will disable the fuel injectors causing the engine to stall immediately after starting.

The components of the Passlock? System are as follows:

The ignition lock cylinder and key The ignition lock cylinder case, including the Passlock? Sensor The ignition switch The body control module (BCM) The security indicator on the instrument cluster The powertrain control module (PCM)

Ignition Lock Cylinder Case, Including the Passlock? Sensor

The ignition lock cylinder fits inside the ignition lock cylinder case and operates the ignition switch when turned by a key with the proper mechanical cut. When the ignition key is used to turn the ignition lock cylinder to crank, start, a magnet on the lock cylinder passes close to the Passlock? Sensor within the ignition lock cylinder case. The magnet activates the Security Hall Effect Sensor in the Passlock? Sensor which completes a circuit from the security sensor signal circuit through a resistor to the security sensor low reference circuit. The resistance value will vary from vehicle to vehicle.

If a magnet from outside of the ignition lock cylinder case is used to attempt to steal the vehicle, the Tamper Hall Effect Sensor will be activated. This completes a circuit from the security sensor signal circuit through a tamper resistor to the security sensor low reference circuit bypassing the security resistor. If the ignition switch is forced to rotate without the correct key, or if the ignition lock cylinder is removed by force, the Passlock? Sensor will be damaged and will not operate.

Ignition Switch

The ignition switch contains the wiring and electrical switching portion of the column mounted ignition assembly. The ignition switch includes wiring pigtails which connect it to the base of column connector, the Passlock? Sensor on the ignition lock cylinder case, and other components. The wiring for the Passlock? Sensor is unaffected by ignition switch position. The electrical switch portion is operated by the key and lock cylinder when they are rotated within the ignition lock cylinder case. The ignition switch operates the crank relay regardless of the status of the Passlock? System.

Body Control Module (BCM)

The BCM contains the logic of the theft deterrent system. The BCM provides the battery positive voltage to operate the Passlock? Sensor. The BCM also measures the voltage of the security sensor signal circuit. The voltage measured will indicate whether the Passlock? Sensor has been activated and whether the resistance value from the sensor is a valid value or the tamper value. If voltage measured is in the valid range, the BCM compares this voltage, voltage code, to a previously learned voltage code. If the voltage codes match, the BCM sends a class 2 message containing a password to the PCM. If the voltage codes do not match, or the voltage is in the Tamper range, or there is a circuit fault, the BCM will not send the correct password to the PCM, and the vehicle will not start.

Powertrain Control Module

The powertrain control module (PCM) contains the remainder of the logic of the theft deterrent system. If a class 2 message containing a valid password is received from the BCM, the PCM will continue to allow the fuel injectors to operate. The PCM will allow the fuel injectors to operate until it decides there is no valid password coming from the BCM. If the PCM does not receive a class 2 message, or receives a class 2 message with an incorrect password, the engine will crank and will not run or will start and stall immediately.

Theft System Indicator

The IPC illuminates the theft deterrent indicator as determined by the theft deterrent system. The IPC receives a class 2 message from the BCM requesting illumination.

The vehicle theft deterrent (VTD) system requests the IPC to illuminate the indicator only when the ignition switch is ON.

The content theft deterrent (CTD) system requests the IPC to illuminate the indicator only when the ignition switch is in the OFF or ACC positions or during RAP.

The body control module performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Fuel Lockout Cycle

When it receives a password which is incorrect or a password which indicates tamper and the PCM disables the fuel injectors, the fuel injectors remain disabled for 10 minutes even if the ignition switch is turned from the RUN position to the OFF position.

Changing the Passlock? Components

The following components contain codes or passwords, or must learn codes or passwords for the Passlock? system to allow the vehicle to start:

The ignition lock cylinder case BCM The powertrain control module (PCM)

If any of these parts are replaced, a learn procedure must be performed. Refer to Programming Theft Deterrent System Components . If parts are replaced and a learn procedure is not performed, the engine will crank and will not run or will start and stall immediately.

Replacing KeysThe ignition lock cylinder and keys do not contain any coded electronic components. The lock cylinder housing contains the coded electronic components. Changing an ignition lock cylinder or replacing a key is a purely mechanical process which does not affect the vehicle theft deterrent system. To replace an existing key, simply cut a new key to match the existing one. If no keys are available, the lock cylinder must be changed. To change the lock cylinder, simply replace the existing lock cylinder with one of the same type.

Adding KeysThe ignition lock cylinder and keys do not contain any coded electronic components. The lock cylinder housing contains the coded electronic components. Changing an ignition lock cylinder or adding a key is a purely mechanical process which does not affect the vehicle theft deterrent system. To add a key, simply cut a new key to match the existing one. To change the lock cylinder, simply replace the existing lock cylinder with one of the same type.

Programming Theft Deterrent System ComponentsImportant

Due to component variability, the vehicle theft deterrent (VTD) system must have the learn procedure performed regardless, if the vehicle starts on the first ignition cycle after a VTD repair.

All codes in the theft deterrent module must be cleared for a relearn.

Important The body control module (BCM) must be programmed with the proper RPO configurations

before performing learn procedures. Refer to BCM Programming/RPO Configuration in Body Control System.

If replacing the BCM with a GM Service Parts Operations (SPO) replacement part, the module will learn Passlock? sensor data code immediately. The existing PCM however, must learn the new fuel continue password when the BCM is replaced.

If replacing a PCM with a GM Service Parts Operations (SPO) replacement part, after programming, these modules will learn the incoming fuel continue password immediately upon receipt of a password message. Once a password message is received, and a password is learned, a learn procedure must be performed to change this password again. A PCM which has been previously installed in another vehicle will have learned the other vehicle's fuel continue password and will require a learn procedure after programming to learn the current vehicle's password.

Conditions

Use these procedures after replacing:

Passlock? Sensor BCM PCM

10 Minute Learn Procedure

Tools Required Tech 2 Techline terminal with current Service Programming System (SPS) software

1. Connect the Tech 2 to the vehicle. 2. Select "Request Information" under "Service Programming". 3. Disconnect the Tech 2 from the vehicle and connect it to a Techline terminal. 4. On the Techline terminal, select "Theft Module Re-Learn" under "Service Programming". 5. Disconnect the Tech 2 from the Techline terminal and connect it to the vehicle. 6. Turn ON the ignition, with the engine OFF. 7. Select "VTD Re-Learn" under "Service Programming". 8. Attempt to start the engine, then release the key to ON. The vehicle will not start. 9. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF. The

vehicle is now ready to relearn the Passlock? Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK.

10. Turn OFF the ignition, and wait 5 seconds. 11. Start the engine. The vehicle has now learned the password. 12. With the Tech 2 scan tool, clear any DTCs.

30 Minute Learn Procedure

Tools Required

None

1. Turn ON the ignition, with the engine OFF. 2. Attempt to start the engine, then release the key to ON. The vehicle will not start. 3. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF. 4. Turn OFF the ignition, and wait 5 seconds. 5. Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes. The vehicle is now

ready to relearn the Passlock? Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.

Important

The vehicle learns the Passlock? Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

6. Start the engine. The vehicle has now learned the Passlock? Sensor Data Code and/or password.

7. With a scan tool, clear any DTCs if needed. History DTCs will self clear after 100 ignition cycles.

Body Control Module Component Views

(1) Data Link Connector (DLC)(2) Brake Pedal(3) Body Control Module (BCM)

Diagrama del BCM

Body Control Module Connector End ViewsTable 1: Body Control Module (BCM) C1Table 2: Body Control Module (BCM) C2Table 3: Body Control Module (BCM) C3Table 4: Traction Control Switch

Body Control Module (BCM) C1

Connector Part Information

12191375

16-Way F Micro-Pack 100 Series (PPL)

Pin Wire Color Circuit No. Function

A1-A2 -- -- Not Used

A3 WHT 194 Door Unlock Control

A4 LT BLU 195 Door Lock Control

A5 BLK/WHT 56 Trunk Release Motor Control

A6 TAN 694 Driver Door Lock Actuator Unlock Control

A7 LT GRN/BLK 394 Driver Door Jamb Switch Signal

A8 LT BLU 395 Passenger Door Jamb Switch Signall

B1-B7 -- -- Not Used

B8 PPL 1807 Class 2 Serial Data

Body Control Module (BCM) C2

Connector Part Information

12110206

24-Way F Micro-Pack 100 Series (LT BLU)

Pin Wire Color Circuit No. Function

A1 BRN 9 Park Lamp Supply Voltage

A2 -- -- Not Used

A3 YEL 43 Accessory Voltage

A4 ORN/BLK 737 Rear Compartment Lamp Control

A5 BRN/WHT 230 Instrument Panel Lamps Dimming Control

A6 PNK 1200 Headlamp High Beam Signal

A7 YEL 1836 Security System Sensor Signal

A8-A9 -- -- Not Used

A10 ORN 1732 Courtesy Lamps Supply Voltage

A11 ORN 1440 Battery Positive Voltage

A12 ORN 340 Battery Positive Voltage

B1 BLK/WHT 451 Ground

B2 LT BLU 1134 Park Brake Switch Signal

B3 -- -- Not Used

B4 BLK/WHT 1576 Rear Compartment Lock Actuator Unlock

B5 -- -- Not Used

B6 DK BLU 1201 Headlamp Low Beam Signal

B7 PPL 1807 Class 2 Serial Data

B8 PPL 1807 Class 2 Serial Data

B9 PPL 1807 Class 2 Serial Data

B10 ORN 1940 Battery Positive Voltage

B11 BLK/WHT 251 Ground

B12 -- -- Not Used

Body Control Module (BCM) C3

Connector Part Information

12160778

24-Way F Micro-Pack 100 Series (BRN)

Pin Wire Color Circuit No. Function

A1 WHT 156 Courtesy Lamp Low Control

A2 GRY 8 Instrument Panel Lamp Supply Voltage

A3 -- -- Not Used

A4 LT GRN/BLK 592 DRL Relay Control

A5 BRN 323 A/T Shift Lock Control (MMO Only)

A6-A8 -- -- Not Used

A9 BRN/WHT 1571Traction Control Switch Signal (Pontiac w/MMO Only)

A10 LT GRN 66 A/C Request Signal

A11 ORN 192 Front Fog Lamp Switch Signal

A12 PNK 39 Ignition 1 Voltage

B1 PPL 719 Low Reference

B2 BLK/WHT 151 Ground

B3 BLK 1835 Security System Sensor Low Reference

B4 -- -- Not Used

B5 DK GRN/WHT 1317 Fog Lamp Relay Control

B6 -- -- Not Used

B7 BLK 28 Horn Relay Control

B8 YEL/BLK 68 Low Coolant Level Indicator Control

B9 GRY 728 Security Indicator Control

B10 WHT 1459 Security System Sensor Supply Voltage

B11 PNK 849 Brake Fluid Level Sensor Signal

B12 LT GRN 80 Key In Ignition Switch Signal

Traction Control Switch

Connector Part Information

12065422

3-Way F Metri-Pack 150 Series (TAN)

Pin Wire Color Circuit No. Function

A BLK 150 Ground

B BRN/WHT 1571 Traction Control Switch Signal

C -- -- Not Used

Body Control System Description and OperationThe body control system consists of a BCM and it's associated controls. Battery positive voltage is provided to the BCM from CLSTR fuse in the Fuse Block-left I/P. The module ground is wired to ground G201. The BCM is wired to the Class 2 serial data communication bus as well as discreet input and output terminals to control the functions of the vehicles body .

Serial Data Power Mode

On vehicles that have several control modules connected by serial data circuits, one module is the Power Mode Master, PMM. On this vehicle the PMM is the BCM. The PMM receives 2 signals from the ignition switch.

To determine the correct power mode the PMM uses the following circuits:

Accessory voltage Ignition 1 voltage

Fail-safe Operation

Since the operation of the vehicle systems depends on the power mode, there is a fail-safe plan in place should the PMM fail to send a power mode message. The fail-safe plan covers those modules using exclusively serial data control of power mode as well as those modules with discrete ignition signal inputs.

Serial Data Messages

The modules that depend exclusively on serial data messages for power modes stay in the state dictated by the last valid PMM message until they can check for the engine run flag status on the serial data circuits. If the PMM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is True, indicating that the engine is running, the modules fail-safe to RUN. In this state the modules and their subsystems can support all operator requirements. If the engine run flag serial data is False, indicating that the engine is not running, the modules fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the

serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Discrete Ignition Signals

Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid PMM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, battery positive voltage, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

BCM Wake-up/Sleep States

The BCM is able to control or perform all of the BCM functions in the wake-up state. The BCM enters the sleep state when active control or monitoring of system functions has stopped, and the BCM has become idle again. The BCM must detect certain wake-up inputs before entering the wake-up state. The BCM monitors for these inputs during the sleep state, where the BCM is able to detect switch transitions that cause the BCM to wake-up when activated or deactivated. Multiple switch inputs are needed in order to sense both the insertion of the ignition key and the power mode requested. This would allow the BCM to enter a sleep state when the key is IN or OUT of the ignition.

The BCM will enter a wake-up state if any of the following wake-up inputs are detected:

Activity on the serial data line. Detection of a battery disconnect and reconnect condition. Headlamps are on. Ignition is turned ON. Key-in-ignition switch. Parklamps are on.

The BCM will enter a sleep state when all of the following conditions exist:

Ignition switch is OFF. No activity exists on the serial data line. No outputs are commanded. No delay timers are actively counting. No wake-up inputs are present.

If all these conditions are met the BCM will enter a low power or sleep condition. This condition indicates that the BCM, which is the PMM of the vehicle, has sent an OFF-ASLEEP message to the other systems on the serial data line.

Body Control Module

The various BCM input and output circuits are described in the corresponding functional areas indicated on the BCM electrical schematics. The Body Control Module functions include the following.

Retained Accessory Power, RAP, Audio System only. Refer to Retained Accessory Power (RAP) Description and Operation

A/C compressor request. Refer to Air Temperature Description and Operation Remote Function Control. Refer to Keyless Entry System Description and Operation

A/C cooling Fan. Refer to Air Delivery Description and Operation Exterior and interior lighting control, Refer to Exterior Lighting Systems Description and

Operation o Daytime running lights (DRL) o Automatic lighting control o Fog lamps

Interior lighting. Refer to Interior Lighting Systems Description and Operation Battery rundown protection (Inadvertent Power). Refer to Interior Lighting Systems

Description and Operation Chimes. Refer to Audible Warnings Description and Operation

o Key In Ignition o Head Lamps On o Seat Belt Not Fastened o Turn Signal On o Park Brake Warning o Door Ajar Warning o Check gauges

Gauge control. Refer to Instrument Panel Cluster (IPC) Description and Operation Instrument cluster indicator control. Refer to Instrument Panel Cluster (IPC) Description and

Operation Theft deterrent. Refer to Theft Systems Description and Operation Engine coolant level sensing. Refer to Cooling System Description and Operation Key-in-ignition sensing. Refer to Audible Warnings Description and Operation Brake fluid level sensing. Refer to Brake Warning System Description and Operation Parking brake state sensing. Refer to Brake Warning System Description and Operation Rear compartment interface. Refer to Power Door Locks Description and Operation Horn interface. Refer to Horns System Description and Operation Door lock interface. Refer to Power Door Locks Description and Operation Bulb Check. Refer to Instrument Panel Cluster (IPC) Description and Operation ETS -Pontiac Only. Refer to ABS Description and Operation A/T Shift lock control. Refer to Automatic Transmission Shift Lock Control Description and

Operation