For 1990-2009 cars

## DTC B0996 Instrument panel

### DTC Descriptors

DTC B0996 00: VIN Mismatch

### Diagnostic Fault Information

Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

### Circuit/System Description

The instrument panel cluster (IPC) learns the model it is installed in, by using the vehicle ID information via the serial data line. Each time the vehicle is in the RUN position or the VIN master module communicates this information, the IPC internally compares the VIN information with the information stored. If the VIN is incorrect, the IPC will indicate a VIN information error is present.

### Conditions for Running DTC

• | System voltage is between 9-16 volts.

• | Ignition switch is in the ON position.

### Conditions for Setting the DTC

• | The VIN message received via the GMLAN does not match the VIN number stored in the IPC.

• | The incorrect IPC is installed on the vehicle.

• | The incorrect software or calibrations have been flash programmed into the IPC.

### Action Taken When the DTC Sets

DTC B0996 00 will set in the event of a VIN mismatch, there will be no indication to the driver unless the IPC is one of three modules that have a VIN mismatch fault. In the event of three modules failing to have the correct VIN stored the vehicle will fail to start.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present.

• | The DTC can be cleared using a scan tool.

### Reference Information

#### Scan Tool Reference

Control Module References

### Circuit/System Testing

1. Ignition OFF, wait for 30 seconds.
2. Ignition ON, using the scan tool, select the DTC display function.

⇒ | If DTC B0996 is set to current, ensure that the body control module (BCM) transmits the VIN, to achieve this perform a 'Module/ECU Presence Check/VIN Check' using the scan tool. The VIN can also be visually verified by reading the 'Additional Functions/Read ECU Identification' data display.

⇒ | If the BCM fails to transmit the VIN, refer to Control Module References for BCM replacement, setup, and programming.

3. Ignition ON, verify that the IPC displays "Security Locked, VIN is Mismatch".

⇒ | If the screen displays "Security Locked, VIN is Mismatch", replace the IPC.

### Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM and IPC replacement, setup, and programming

## DTC B0996 SIR

### DTC Descriptors

DTC B0996 00: Vehicle Identification Number Mismatch

### Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

### Circuit/System Description

The inflatable restraint sensing and diagnostic module (SDM) learns the model it is installed in, by using the vehicle ID information via the serial data line. Each time the vehicle is in the RUN position or the VIN master module communicates this information the SDM internally compares the VIN information with the information stored. If the VIN is incorrect, the SDM will indicate a VIN information error is present.

### Conditions for Running DTC

• | System voltage is between 9-16 volts.

• | Ignition switch is in the ON position.

### Conditions for Setting the DTC

• | The VIN message received via the GMLAN does not match the VIN number stored in the SDM.

• | The incorrect SDM is installed on the vehicle.

• | The incorrect software or calibrations have been flash programmed into the SDM.

### Action Taken When the DTC Sets

DTC B0996 00 will set in the event of a VIN mismatch, there will be no indication to the driver unless the SDM is one of three modules that have a VIN mismatch fault. In the event of three modules failing to have the correct VIN stored the vehicle will fail to start.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present.

• | The DTC can be cleared using a scan tool.

### Reference Information

#### Scan Tool Reference

Control Module References

### Circuit/System Testing

1. Ignition ON, use the scan tool to request SIR DTCs. Verify that DTC B0996 is set as current.

⇒ | If DTC B0996 is history, clear codes and re-test.

2. Use the scan tool in the SIR menu, go to Data Display then SIR menu, then go to Key Identification menu. Look at the Secondary Key Status to see if the scan tool shows this as being Valid. Verify the scan tool shows this Secondary Key Status is Valid.

⇒ | If the Secondary Key Status is not valid then look at the Received VIN Digits 2-7. Compare Received VIN Digits to the vehicle VIN.

⇒ | If the VIN is different from the vehicle, then the BCM has the incorrect VIN programmed. Use the scan tool to program the BCM.

3. Use the scan tool in the SIR menu, go to Data Display then SIR menu, then go to Key Identification menu. Look at the Primary Key Status to see if the scan tool shows this as being Valid. Verify the scan tool shows the Primary Key Status is Valid.

⇒ | If the Primary Key Status is not valid, then look at the Received Primary Key. Compare Received Primary Key to the stored SDM Primary Key. If the IPC Primary Key differs from the Received Primary Key, use the scan tool to Setup SDM Primary Key into BCM procedure.

4. Ignition ON, use the scan tool to clear the DTCs. Verify that DTC B0996 is no longer set as current

⇒ | If DTC B0996 is still current, replace the IPC.

### Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM and IPC replacement, setup, and programming

## DTC B0996 Immobilizer

### DTC Descriptor

DTC B0996: Vehicle VIN Check Error (Vehicle Identification Number)

### Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle .

### Circuit/System Description

The Vehicle Identification Number (VIN) received by the theft deterrent module (TDM) fails to correspond with the VIN stored, creating a mismatch fault.

### Conditions for Running DTC

When received VIN is matched to the VIN stored in EEPROM.

### Conditions for Setting the DTC

The DTC will set when there is a VIN mismatch.

### Action Taken When DTC Sets

The system will enter Theft Detected Mode.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present.

• | The history DTC will clear after 50 fault-free ignition cycles.

• | The DTC can be cleared using a scan tool.

### Reference Information

#### Scan Tool Reference

Control Module References

### Circuit/System Testing

1. Ignition OFF, wait for 30 seconds.
2. Ignition ON, using the scan tool, select the DTC display function.

⇒ | If DTC B0996 is set to current, observe using the scan tool that the body control module (BCM) transmits the VIN. If the BCM fails to transmit the VIN, refer to Control Module References .

3. Ignition ON, infotainment system ON, verify that the screen displays "Security Locked, VIN is Mismatch".

⇒ | If the infotainment system displays a "Security Locked, VIN is Mismatch" message, replace the infotainment unit.

### Repair Instructions

Perform the Diagnostic Repair Verification .

Control Module References .