U1109

U1109-LOST COMMUNICATION WITH LIN STEERING WHEEL CONTROLS

For a complete wiring diagram Refer to Diagrams/Electrical. 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.








Diagnostic Test


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.

Ignition on, engine not running.

With the Scan Tool, select View DTCs in the Steering Control Module.

Is the DTC status Active at this time?

Yes

- Go to 2

No

- Go to 6



2. LIN BUS WIRING AND CONNECTORS

Turn the ignition off.

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.

Disconnect the Right Steering Switch harness connector.

Disconnect the C206 harness connector.

Measure the resistance of the following LIN Bus circuits:
- The (D500) LIN Bus circuit between the Right Steering Switch harness connector and the C206 harness connector (Steering Pad side).
- The (D501) LIN Bus Slave Return circuit between the Right Steering Switch harness connector and the C206 harness connector (Steering Pad side).
- The (D502) LIN Bus Slave Feed circuit between the Right Steering Switch harness connector and the C206 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.

No

- Go to 3



3. CLOCKSPRING

Remove the Clockspring.

Measure the resistance of the following LIN Bus circuits:
- The (D500) LIN Bus circuit between the Clockspring connector to the SCM and the C206 harness connector (Clockspring side).
- The (D501) LIN Bus Slave Return circuit between the Clockspring connector to the SCM and the C206 harness connector (Clockspring side).
- The (D502) LIN Bus Slave Feed circuit between the Clockspring connector to the SCM and the C206 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.
-

No

- Go to 4



4. RIGHT STEERING SWITCH

Replace the Right Steering Switch.

Reconnect the Clockspring.

Reconnect the C206 (LIN Bus) connector.

Turn the ignition on.

With the scan tool, select Clear Stored DTCs in the Steering Control Module.

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)

View repair.



Repair

- Replace the Steering Control Module (SCM).



6. INTERMITTENT LOST COMMUNICATION WITH LIN STEERING WHEEL CONTROLS DTC

The conditions necessary to set this DTC are not present at this time.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.

Look for the data to change or for the DTC to reset during the wiggle test.

Were any problems found?

Yes

- Repair as necessary.

No

- Test complete.