For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC B2960: Security System Sensor Data Incorrect but Valid

### Circuit/System Description

The Passlock™ system is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate. The Passlock™ controller reads the coded Passlock™ data signal. The data consists of a voltage generated by a voltage divider network created between the Passlock™ assembly and the Passlock™ controller. If the data is correct, indicating rotation of the lock cylinder with the proper mechanically cut key, then the Passlock™ controller sends a password to the powertrain controller via serial data to indicate that engine starting should be allowed. The Passlock™ controller also interfaces with the driver displays subsystem to indicate, via the security indicator, the Passlock™ subsystem status and acute subsystem failures.

### Conditions for Setting the DTC

• | The body control module (BCM) will inspect for a valid code when the ignition is rotated from ON to CRANK and will continue to monitor the signal during the engine running period.

• | The BCM is reading a valid but different code value than previously learned form the Passlock™ sensor.

### Action Taken When the DTC Sets

• | The vehicle will not start if the fault occurs before you start the vehicle. The security indicator will be FLASHING.

• | If the vehicle is running when the fault occurs, the BCM will be in the fail enable mode allowing the vehicle to start and run. The security indicator will be ON.

### Conditions for Clearing the DTC

• | The DTC will clear once an ignition cycle occurs without the fault recurring.

• | The BCM history codes will clear once 100 concurrent ignition cycles occur without the fault recurring.

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

### Diagnostic Aids

• | Use a scan tool in order to inspect the Passlock™ data voltage and the Passlock™ code.

• | Inspect for poor connections at the Passlock™ sensor.

### Reference Information

#### Schematic Reference

Immobilizer Schematics

#### Connector End View Reference

Master Electrical Component List

#### Description and Operation

Immobilizer Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Testing

1. Install the scan tool. Attempt to CRANK but do not start the vehicle and release the ignition switch to ON. Verify DTC B2960 is set as current.

⇒ | If DTC B2960 is set as current along with DTC B2957, B2958 or B3033, proceed to diagnose DTC B2957 , DTC B2958 or DTC B3033 .

2. Perform the Programming Theft Deterrent System Components procedure.
3. If DTC B2960 is current a problem exists with the Passlock™ sensor and/or the wiring harness.

⇒ | Inspect for poor connections at the Passlock™ sensor. Make the appropriate repair.

⇒ | Replace the ignition and start switch. Refer to Repair Instructions.

4. Perform the Programming Theft Deterrent System Components procedure.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Ignition and Start Switch Replacement

• | Control Module References for BCM replacement, setup, and programming