GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The driver position module (DPM) receives voltage inputs from contacts inside the tilt/telescoping switch. The DPM then supplies battery voltage to the telescope motor forward or reverse circuit depending on which direction of movement is requested. The motor is reversible and the circuits are simply reversed to accomplish movement in opposite directions.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

DTC B2850 Telescope Forward Switch Circuit

This vehicle has DTCs which include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description .

DTC Symptom

DTC Symptom Descriptor

01

Short to Battery +

Conditions for Running the DTC

The DPM is ON.

Conditions for Setting the DTC

The DPM detects a telescope forward switch input for more than 30 consecutive seconds after forward movement of the motor has stopped.

Action Taken When the DTC Sets

    • The telescope motor 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    • A current DTC will clear when the failed switch input is no longer active.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. Refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Tilt/Telescoping Steering Column Schematics

Connector End View References: Steering Wheel and Column Connector End Views , Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn ON the ignition, with the engine OFF.
  2. Retrieve DTCs with a scan tool.

Is DTC B2850 displayed as current?

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect the tilt/telescoping switch harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Retrieve DTCs with the scan tool.

Is DTC B2850 displayed as current?

Go to Step 4

Go to Step 5

4

Inspect for poor connections at the harness connector of the tilt/telescope switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 7

Go to Step 6

5

Replace the tilt/telescope switch. Refer to Telescope Actuator Switch Replacement .

Did you complete the replacement?

Go to Step 7

--

6

Important: Perform the set up procedure for the DPM. .

Replace the DPM. Refer to Control Module References .

Did you complete the replacement?

Go to Step 7

--

7

Calibrate the tilt/telescoping steering column. Refer to Telescoping Steering Column Calibration .

Did you complete the action?

Go to Step 8

--

8

  1. Clear the DTCs with the scan tool.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does DTC B2850 reset?

Go to Step 2

System OK