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

Key In Ignition Alarm Switch Signal Circuit

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B2961

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Circuit Description

The body control module (BCM) uses a key in ignition input in order to control certain features in the vehicle. These features are in the following systems:

    • Content theft deterrent (CTD), if equipped
    • Audible warnings
    • Automatic door locks (ADL)

The ignition switch switches the key in ignition input circuit to ground when you fully insert the ignition key into the ignition switch. This in turn pulls the BCM key in ignition input low.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

    • The ignition 0 input is active, high signal and the key in ignition input is inactive, high signal.
    • The conditions above must be present for more than 0.3 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 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 the 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 key alarm switch.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit and ground.
  3. If greater than 1.0 ohm test the ground circuit for an open/high resistance.
  4. Ignition ON, install a 3-amp fused jumper between the signal circuit and ground. Verify the scan tool Key In Ignition parameter displays Active.
  5. If not Active, 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