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 Descriptors

DTC B2902 01: Tilt And Telescope 4-Way Position Switch Circuit Short To Battery

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Tilt/Telescope Switch Battery Positive Voltage

1*

1

--

--

Steering Column Tilt and Telescope Down Switch Signal

1*

2

B2902 01

--

Steering Column Tilt and Telescope Forward Switch Signal

1*

3

B2902 01

--

Steering Column Tilt and Telescope Reverse Switch Signal

1*

4

B2902 01

--

Steering Column Tilt and Telescope Up Switch Signal

1*

5

B2902 01

--

* Open HUD Fuse

  1. Tilt and telescope inoperative
  2. Tilt down inoperative
  3. Telescope forward inoperative
  4. Telescope reverse inoperative
  5. Tilt up inoperative

Circuit/System Description

The instrument panel module (IPM) receives voltage inputs from contacts inside the tilt/telescope switch. The IPM sends the tilt/telescope switch information to the memory seat module (MSM) via the low speed GMLAN serial data circuit. The MSM then supplies battery voltage to the tilt motor up or down circuit, or the telescope motor in or out circuit depending on which direction of movement is requested. Both motors are reversible and voltage is applied to either circuit to accomplish movement in opposite directions. The MSM monitors the position and movement of the tilt and telescoping actuators on the sensor signal circuits.

Conditions for Running the DTC

Ignition ON

Conditions for Setting the DTC

The MSM detects a switch input for greater than 30 consecutive seconds after movement of the motor in the requested direction has stopped.

Action Taken When the DTC Sets

    • The motor that is being driven by the failed switch will be deactivated.
    • Memory recall functions will be disabled.

Conditions for Clearing the DTC

    • A current DTC will clear when the failed switch input is no longer active.
    • A history DTC will clear after 100 ignition cycles.

Diagnostic Aids

An intermittently stuck switch can cause this DTC to set. Also, the driver can cause this DTC to set by holding the switch for 30 seconds after the column reaches the end of its travel.

Reference Information

Schematic Reference

Tilt/Telescoping Steering Column Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Steering Wheel and Column Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for Scan Tool Information

Circuit/System Verification

Ignition ON, observe the following parameters in the Instrument Panel Module Data Display of the scan tool.

    • Tilt Up Switch
    • Tilt Down Switch
    • Telescope Forward Switch
    • Telescope Rearward Switch

The scan tool should display Inactive for all 4 parameters when the switch is not pressed, and Active for any switch that is pressed.

Circuit/System Testing

  1. Ignition OFF, disconnect the X2 harness connector at the IPM.
  2. Ignition ON, test for less than 1 volt on each of the switch signal circuits terminals 13, 14, 21, and 22.
  3. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the switch.
  4. If all circuits test normal, test or replace the IPM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Turn Signal Multifunction Switch Replacement
    •  Control Module References for IPM replacement, setup, and programming