U1109

U1109-LOST COMMUNICATION WITH LIN STEERING WHEEL CONTROLS





For a complete wiring diagram, refer to the wiring information Electrical Diagrams.

Theory of Operation

The Steering Wheel Control Switch status is transferred to the Steering Control Module (SCM) by way of the LIN bus, a serial sub-bus. The SCM converts the data to CAN and sends the messages to the corresponding module(s) on the bus.

- When Monitored:
Continuously with the ignition on.

- Set Condition:
There is no response from the Steering Column Control (LIN) Switch for 10 ms.





1. DTC IS ACTIVE

NOTE: If P0562-BATTERY VOLTAGE LOW or P0563-BATTERY VOLTAGE HIGH is set along with this DTC, diagnose the battery voltage DTC first.

1. Turn the ignition on.
2. With the scan tool, read SCM DTCs.

Is this DTC active?

Yes

- Go To 2

No

- The condition that caused this code to set is not present at this time. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. LIN BUS WIRING AND CONNECTORS
1. Turn the ignition off.
2. Remove the Driver Airbag.

NOTE: Before proceeding, thoroughly inspect the wiring harness and connectors between the Clockspring and the Right Steering Switch for a short to ground or any other circuit.

3. Disconnect the Right Steering Switch harness connector.
4. Disconnect the SCM C4 harness connector.
5. Measure the resistance of the following LIN Bus circuits:
- The (D500) LIN Bus circuit between the Right Steering Switch harness connector and the SCM C4 harness connector (Steering Pad side).
- The (D501) LIN Bus Slave Return circuit between the Right Steering Switch harness connector and the SCM C4 harness connector (Steering Pad side).
- The (D502) LIN Bus Slave Feed circuit between the Right Steering Switch harness connector and the SCM C4 harness connector (Steering Pad side).

Is the resistance above 5.0 Ohms for any of the LIN Bus circuits?

Yes

- Repair the LIN Bus circuit(s) for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. CLOCKSPRING
1. Remove the Clockspring.
2. Measure the resistance of the following LIN Bus circuits:
- The (D500) LIN Bus circuit between the Clockspring connector to the SCM and the SCM C4 harness connector (Clockspring side).
- The (D501) LIN Bus Slave Return circuit between the Clockspring connector to the SCM and the SCM C4 harness connector (Clockspring side).
- The (D502) LIN Bus Slave Feed circuit between the Clockspring connector to the SCM and the SCM C4 harness connector (Clockspring side).

Is the resistance above 5.0 Ohms for any of the LIN Bus circuits?

Yes

- Repair the LIN Bus circuit(s) for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. RIGHT STEERING SWITCH
1. Replace the Right Steering Switch.
2. Reconnect the Clockspring.
3. Reconnect the C206 (LIN Bus) connector.
4. Turn the ignition on.
5. With the scan tool, select Clear Stored DTCs in the Steering Control Module.
6. With the scan tool, select View DTCs in the Steering Control Module.

Does the DTC reset?

Yes

- Go To 5

No

- Test complete.

5. STEERING CONTROL MODULE (SCM)

Repair

- Replace the Steering Control Module (SCM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.