GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 XLR 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC B2907

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 Descriptors

DTC B2907 01: Steering Column Lock Motor Enable Circuit Short to Battery

DTC B2907 06: Steering Column Lock Motor Enable Circuit Short to Ground or Open

Circuit/System Description

The steering column lock control module (SCLCM) receives an input from the body control module (BCM) on the steering column lock control circuit. When the BCM detects that the park switch is closed, and it goes to the off power mode, then a low input is sent to the SCLCM. If the SCLCM detects a malfunction on the steering column lock control circuit, then DTC B2907 will set.

Conditions for Running the DTC
    • The ignition is ON.
    • DTCs B1327 or B1328 are not set as current.

Conditions for Setting the DTC

The SCLCM detects a malfunction on the steering column lock enable relay circuit

Actions Taken When DTC Sets
    • The steering column may not lock or unlock.
    • DTC B2907 is stored in the SCLCM memory.
    • The SCLCM will command the driver information center (DIC) to display the Service Column Lock Now message.

Conditions for Clearing the DTC
    • Ground has been received on the steering column lock enable relay circuit for 300 ms, when the vehicle is in Park and the ignition is turned OFF.
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.

Reference Information

Schematic Reference

Column Lock Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Steering Wheel and Column Description and Operation

Electrical Information Reference

    •  Testing for Intermittent Conditions and Poor Connections
    •  Circuit Testing

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing
  1. Verify that there are no DTCs in the BCM.
    2. ⇒If there are any DTCs in the BCM, diagnose those DTCs first.
  2. Ignition ON. Monitor the Park Switch (Auto) in the BCM Data with a scan tool. Shift the transmission range selector in and out of Park. Verify that the scan tool display changes between Active and Inactive.
    3. ⇒If the Park Switch (Auto) does not change between Active and Inactive, test or repair the BCM park signal circuit.
  3. Ignition ON. Monitor the Column Lock Relay Signal in the Steering Column Data with a scan tool. Shift the vehicle into Park and turn off the ignition. Verify that the scan tool display changes from Off to On.
    4. ⇒If the BCM Column Lock Relay Signal does not change between OFF and ON, test or repair the steering column lock enable relay circuit.
    ⇒If the steering column lock enable relay circuit is OK, test or replace the BCM.
  4. If all circuits test normal, replace the SCLCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for SCLCM or BCM replacement, setup and programming