The instrument panel module (IPM) receives voltage inputs from the tilt/telescope switch based on the position of the switch. The IPM then sends a low speed GMLAN serial data message to the memory seat module (MSM). The MSM supplies battery voltage and a ground to the tilt or telescope motor control circuits depending on which direction of movement is requested.

The MSM determines the position of the steering column based on inputs received from the telescope position sensor, built into the telescoping actuator. The MSM supplies a 5-volt reference and a low reference to the sensor and monitors the column position via the steering column telescope sensor signal circuit.

Schematic Reference

Tilt/Telescoping Steering Column Schematics

Connector End View Reference

Description and Operation

Steering Wheel and Column Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the scan tool Tilt Up Switch, Tilt Down Switch, Telescope Forward Switch and Telescope Rearward Switch parameters while cycling the tilt/telescope switch between the TILT UP, TILT DOWN, TELESCOPE IN, and TELESCOPE OUT positions. The appropriate parameter should cycle between Active and Inactive.

⇒	If any of the parameters do not cycle between the specified values, refer to Tilt/Telescope Switch Circuit Malfunction.

2. Observe the scan tool Tilt Sensor and Telescope Sensor parameters. Both reading should be between 0.2 and 4.8 volts.

⇒	If not within the specified range, refer to Tilt/Telescope Sensor Circuit Malfunction.

3. Command the column to tilt up and down and telescope in and out using the tilt/telescope switch. The column should move in the commanded direction.

⇒	If the column does not operate as specified, refer to Tilt/Telescope Actuator Circuit Malfunction.

Tilt/Telescope Switch Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the tilt/telescope switch.
2. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 4 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Verify the all the scan tool tilt/telescope switch parameters listed below are Inactive.

•	Tilt Up Switch - signal circuit terminal 5

•	Tilt Down Switch - signal circuit terminal 1

•	Telescope Forward Switch - signal circuit terminal 3

•	Telescope Reverse Switch - signal circuit terminal 2

⇒	If any of the parameters are not the specified value, test the appropriate signal circuit terminal for a short to voltage. If the circuit tests normal, replace the MSM.

4. Install a 3A fused jumper wire between the signal circuit terminals listed below and the B+ circuit terminal 4. Verify the appropriate scan tool tilt/telescope switch parameter is Active.

•	Tilt Up Switch - signal circuit terminal 5

•	Tilt Down Switch - signal circuit terminal 1

•	Telescope Forward Switch - signal circuit terminal 3

•	Telescope Reverse Switch - signal circuit terminal 2

⇒	If not the specified value, test the appropriate signal circuit for a short to ground or 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 Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector X2 at the appropriate tilt/telescope actuator.
2. Ignition OFF, test for less than 2.0 ohms between the low reference circuit terminal A and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal B and ground.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.

4. Verify the appropriate scan tool tilt/telescope sensor parameter is less than 0.2 volt.

⇒	If greater than the specified range, test the signal circuit terminal C for a short to voltage. If the circuit tests normal, replace the MSM.

5. Install a 3A fused jumper wire between the signal circuit terminal C and the 5-volt reference circuit terminal B. Verify the appropriate scan tool tilt/telescope sensor parameter is greater than 4.8 volts.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.

6. If all circuits test normal, test or replace the appropriate tilt/telescope actuator.

Tilt/Telescope Actuator Circuit Malfunction

1. Ignition OFF, disconnect the harness connector X1 at the appropriate tilt/telescope actuator.
2. Install a test lamp between the control circuit terminal A and the control circuit terminal B.
3. Command the column to tilt up and down or telescope in and out using the tilt/telescope switch. The test lamp should illuminate with each command.

⇒	If the test lamp does not illuminate, test both control circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the MSM.

4. If all circuits test normal, test or replace the appropriate tilt/telescoping actuator.

Tilt/Telescope Switch

1. Ignition OFF, disconnect the harness connector at the tilt/telescope switch.
2. Test for infinite resistance between the terminals listed below with the switch in the neutral position:

•	B+ terminal 4 and signal terminal 5

•	B+ terminal 4 and signal terminal 1

•	B+ terminal 4 and signal terminal 3

•	B+ terminal 4 and signal terminal 2

⇒	If less than the specified range, replace the tilt/telescope switch.

3. Test for less than 1 ohm between the B+ terminal 4 and the signal terminal 5 with the switch in the TILT UP position.

⇒	If greater than the specified range, replace the tilt/telescope switch.

4. Test for less than 1 ohm between the B+ terminal 4 and the signal terminal 1 with the switch in the TILT DOWN position.

⇒	If greater than the specified range, replace the tilt/telescope switch.

5. Test for less than 1 ohm between the B+ terminal 4 and the signal terminal 3 with the switch in the TELESCOPE OUT position.

⇒	If greater than the specified range, replace the tilt/telescope switch.

6. Test for less than 1 ohm between the B+ terminal 4 and the signal terminal 2 with the switch in the TELESCOPE IN position.

⇒	If greater than the specified range, replace the tilt/telescope switch.

Tilt/Telescoping Actuator

1. Ignition OFF, disconnect the harness connector X1 at the appropriate tile/telescoping actuator.
2. Test for less than 2.0 ohms between the control terminal A and the control terminal B.

⇒	If greater than the specified range, replace the appropriate tilt/telescoping actuator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.