DTC B0996 with RPO Y41
Diagnostic Instructions
DTC Descriptor
DTC B0996 00 : Vehicle Electronic Control Unit (ECU) VIN Check Error
Circuit/System Description
After a loss of battery power has been restored, the remote control door lock receiver (RCDLR) will perform a check on the stored vehicle identification number (VIN). If the VIN is CORRECT, the RCDLR will run the VIN Timer for a programmable length of
time, typically 10 minutes. The RCDLR will send a message via the serial data circuit to the instrument panel cluster (IPC) to illuminate the SECURITY indicator. After the VIN Timer has timed out, the security indicator will turn OFF. If the VIN is INCORRECT,
the RCDLR will send the fuel disable password to the engine control module (ECM), via the serial data circuit. The immobilizer system considers this to be a tamper and will not allow the vehicle to start. The RCDLR will send a message via the serial data circuit
to the IPC to flash the SECURITY indicator.
Substitution detection is based on correct response from the following modules: instrument panel cluster (IPC), export body control module (XBCM), driver door module (DDM), passenger door module (PDM). The modules compare their VIN to that stored in the
VIN master on every ignition ON cycle and report their status to the theft deterrent module.
Conditions for Running the DTC
Ignition ON
Conditions for Setting the DTC
| • | The VIN check flag of the RCDLR is true. |
| • | The RCDLR has determined that the battery has been reconnected after a battery disconnect. |
Action Taken When the DTC Sets
| • | The vehicle will not start. |
| • | The RCDLR sends the fuel disable message via the serial data circuit to the ECM. |
| • | The RCDLR will run the VIN Timer for a programmable length of time, typically 10 minutes. |
| • | The RCDLR sends a message to the IPC to illuminate the SECURITY indicator. |
Conditions for Clearing the DTC
The RCDLR clears the current DTC when the correct VIN information is present.
Reference Information
Schematic Reference
Immobilizer Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Immobilizer Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for scan tool information
Circuit/System Verification
- With a scan tool, verify the stored VIN in the following modules matches the actual vehicle VIN:
| ⇒ | If any modules stored VIN does not match the actual VIN, perform the setup procedure for that module. If the stored VIN does not match after setup, replace the module. |
- If all modules VIN match, replace the RCDLR.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Control Module References
for XBCM, RCDLR, IPC, DDM, PDM replacement, setup, and programming
DTC B0996 without RPO Y41
Diagnostic Instructions
DTC Descriptor
DTC B0996 00 : Vehicle Electronic Control Unit (ECU) VIN Check Error
Circuit/System Description
After a loss of battery power has been restored, the theft deterrent module (TDM) will perform a check on the stored vehicle identification number (VIN). If the VIN is CORRECT, the TDM will run the VIN Timer for a programmable length of time, typically
10 minutes. The TDM will send a message via the serial data circuit to the instrument panel cluster (IPC) to illuminate the SECURITY indicator. After the VIN Timer has timed out, the security indicator will turn OFF. If the VIN is INCORRECT, the TDM will
send the fuel disable password to the engine control module (ECM), via the serial data circuit. The immobilizer system considers this to be a tamper and will not allow the vehicle to start. The TDM will send a message via the serial data circuit to the IPC to
flash the SECURITY indicator.
Substitution detection is based on correct response from the following modules: instrument panel cluster (IPC), export body control module (XBCM), driver door module (DDM), passenger door module (PDM). The modules compare their VIN to that stored in the
VIN master on every ignition ON cycle and report their status to the theft deterrent module.
Conditions for Running the DTC
Ignition ON
Conditions for Setting the DTC
| • | The VIN check flag of the TDM is true. |
| • | The TDM has determined that the battery has been reconnected after a battery disconnect. |
Action Taken When the DTC Sets
| • | The vehicle will not start. |
| • | The TDM sends the fuel disable message via the serial data circuit to the ECM. |
| • | The TDM will run the VIN Timer for a programmable length of time, typically 10 minutes. |
| • | The TDM sends a message to the IPC to illuminate the SECURITY indicator. |
Conditions for Clearing the DTC
The TDM clears the current DTC when the correct VIN information is present.
Reference Information
Schematic Reference
Immobilizer Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Immobilizer Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for scan tool information
Circuit/System Verification
- With a scan tool, verify the stored VIN in the following modules matches the actual vehicle VIN:
| ⇒ | If any modules stored VIN does not match the actual VIN, perform the setup procedure for that module. If the stored VIN does not match after setup, replace the module. |
- If all modules VIN match, replace the TDM.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Control Module References
for XBCM, TDM, IPC, DDM, PDM replacement, setup, and programming
