GM Service Manual Online
For 1990-2009 cars only

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 B2961 : Key In Ignition Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ignition Key Alarm Switch Signal Circuit

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B2961

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Circuit/System Description

The body control module (BCM) monitors the ignition key alarm switch. When the key is in the ignition, the ignition key alarm switch is closed and the signal circuit is low. When the key is not in the ignition, the ignition key alarm switch is open and the signal circuit is high.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

    • The ignition 1 voltage circuit is active and the key in ignition switch signal circuit is active and the signal circuit is high.
    • The above condition is present for greater than 5 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B2961 in memory.

Conditions for Clearing the DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 100 malfunction-free warm-up cycles.
    • The BCM receives a clear code command from the scan tool.

Diagnostic Aids

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Reference Information

Schematic Reference

    •  Instrument Cluster Schematics
    •  Body Control System Schematics
    •  Ignition Lock Schematics

Connector End View Reference

    •  Displays and Gages Connector End Views
    •  Data Communication Connector End Views

Description and Operation

    •  Power Mode Description and Operation
    •  Body Control System 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. Ignition OFF, disconnect the harness connector at the ignition switch.
  2. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage supply circuit and ground.
  3. If the test lamp does not illuminate, repair the voltage supply circuit for a short to ground or an open/high resistance. If the ignition switch fuse is open, also test the signal circuit for a short to ground.
  4. Install a 3-amp fused jumper wire between the signal circuit and the voltage supply circuit. Verify the scan tool Key In Ignition parameter displays Yes.
  5. If not Yes, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
  6. 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