GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 STS 🢒 Steering 🢒 Steering Wheel and Column 🢒 Steering Column Tilt/Telescoping Inoperative

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Tilt/telescope switch B+

8

7

--

--

Steering Column Tilt Up Switch Signal

8

1

B2873

--

Steering Column Tilt Down Switch Signal

8

2

B2878

--

Steering Column Telescope Reverse Switch Signal

8

3

B2858

--

Steering Column Telescope Forward Switch Signal

8

4

B2853

--

Steering Column Tilt Motor Control - Up

5

5

5

--

Steering Column Tilt Motor Control - Down

5

5

5

--

Steering Column Telescope Motor Control - Forward

6

6

6

--

Steering Column Telescope Motor Control - Reverse

6

6

6

--

1. Tilt up inoperative

2. Tilt down inoperative

3. Telescope reverse inoperative

4. Telescope forward inoperative

5. Tilt up/down inoperative

6. Telescope forward/reverse inoperative

7. All tilt/telescope functions inoperative

8. All tilt/telescope functions inoperative - HUD fuse open

Circuit/System Description

The instrument panel module (IPM) receives voltage inputs from the tilt/telescoping switch. The IPM sends a signal to the memory seat module (MSM) over the serial data line. The MSM supplies battery voltage to the telescope in and out or tilt up and down motor depending on the movement requested. The telescope and tilt motors are bi-directional operating.

Reference Information

Schematic Reference

Tilt/Telescoping Steering Column Schematics

Connector End View Reference

Steering Wheel and Column 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

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification
  1. Ignition ON, observe the scan tool tilt/telescope parameters while individually pressing each tilt/telescope of the switches. The reading should change between active and inactive.
    2. ⇒If the parameters do not change, refer to tilt/telescope switch malfunction.
  2. Observe the operation of the steering column while pressing the various tilt/telescope switches.
    3. ⇒If the column does not tilt and telescope as each switch is pressed, refer to tilt/telescope motor malfunction.

Circuit/System Testing

Tilt/Telescope Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the tilt/telescope.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal F and ground.
    3. ⇒If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the signal circuits for short to ground.
  3. Verify the scan tool parameter for the appropriate switch is inactive.
    4. ⇒If not the specified value, test the signal circuit terminal for a short to voltage. If the circuit tests normal, replace the IPM.
  4. Install a 3-A fused jumper wire between the appropriate signal circuit terminal and the B+ circuit terminal F. Verify the scan tool parameter is active.
    5. ⇒If not the specified value, test the appropriate signal circuit for an open/high resistance. If the circuit tests normal, replace the IPM.
  5. If all circuits test normal, test or replace the tilt/telescope switch.

Tilt/Telescope Motor Malfunction

  1. Ignition OFF, disconnect the C1 harness connector at the applicable actuator.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal A of the applicable actuator and ground.
    3. ⇒If greater then the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the MSM.
  3. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal B of the applicable actuator and ground.
    4. ⇒If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the MSM.
  4. Connect a test lamp between the control circuit terminal A and the control circuit terminal B of the applicable actuator.
  5. Command the applicable actuator to each of the function states with the scan tool. The test lamp should turn ON when commanding each of the desired states.
    6. ⇒If the test lamp remains OFF during any of the commanded states, test for a short to ground on either control circuit of the applicable actuator. If the circuits test normal, replace the MSM.
  6. If all circuits test normal, test or replace the applicable actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Tilt Motor Replacement
    •  Steering Column Trim Covers Replacement
    •  Telescope Actuator Assembly Replacement
    •  Control Module References for MSM replacement, setup, and programming