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 B2965: Key In Ignition Circuit Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Key In Ignition Alarm Switch Signal Circuit | -- | B2965 | -- | --

### Circuit Description

The ignition switch closes, signal circuit is low, when the key is in the ignition and opens, signal circuit is high, when the key is not in the ignition. The body control module (BCM) monitors the key in ignition signal circuit in order to activate an audible warning.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

• | The ignition 1 voltage circuit is active, high signal, and the key in ignition signal circuit is high.

• | The conditions above must be present for more than 0.3 second.

### Action Taken When the DTC Sets

The BCM stores DTC B2965 in memory.

### Conditions for Clearing the DTC

• | The DTC becomes history when the fault is no longer present.

• | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

• | The BCM receives a clear code command from the scan tool.

### Reference Information

#### Schematic Reference

• | Audible Warnings Schematics

• | Body Control System Schematics

#### Connector End View Reference

• | Displays and Gages Connector End Views

• | Data Communication Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Scan Tool Data List

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the ignition switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit and ground.

⇒ | If greater than 1 ohm test the ground circuit for an open/high resistance.

3. Ignition ON, install a 3-amp fused jumper between the signal circuit and ground. Verify the scan tool Key In Ignition parameter displays Yes.

⇒ | If not Yes, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

4. Ignition ON, engine OFF, verify the Ignition 1 Input parameter displays Off.

⇒ | If not Off, test the ignition 1 voltage circuit for a short to voltage.

5. If all circuits test normal, test or replace the ignition switch.

### 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