B1489

B1489-STEERING WHEEL CONTROL AUDIO SWITCH CIRCUIT





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


Theory of Operation


The Steering Wheel Control Audio Switch, when pressed, sends a multiplexed signal to the Right Steering Switch. The switching 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(B) and sends the message to the corresponding module on the bus.


- When Monitored:

Continuously with the ignition on.

- Set Condition:

The Steering Control Module senses that the Steering Wheel Control Audio Switch is in the Set position for greater than 50 seconds.








Diagnostic Test


1. DTC STATUS IS ACTIVE

NOTE: If U1109-LOST COMMUNICATION WITH LIN STEERING WHEEL CONTROLS is set along with this DTC, diagnose the communication DTC first.

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 7



2. (G206) EVIC MUX SIGNAL 2 CIRCUIT SHORT TO (G907) EVIC/NAV MUX RETURN CIRCUIT





Turn the ignition off.

Remove the Driver Airbag to gain access to the Steering Wheel Control Switches.

Disconnect the Left Steering Switch harness connector.

Disconnect the Right Steering Switch harness connector.


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

Measure the resistance between the (G206) EVIC MUX Signal 2 circuit and the (G907) EVIC/NAV MUX Return circuit.

Is the resistance below 5.0 ohms?

Yes

- Repair the (G206) EVIC MUX Signal 2 circuit for a short to the (G907) EVIC/NAV MUX Return circuit.

No

- Go to 3



3. (G206) EVIC MUX SIGNAL 2 CIRCUIT SHORT TO GROUND






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

Measure the resistance between the (G206) EVIC MUX Signal 2 circuit and ground.

Is the resistance below 5.0 ohms?

Yes

- Repair the (G206) EVIC MUX Signal 2 circuit for a short to ground.

No

- Go to 4



4. LEFT STEERING SWITCH





Reconnect the Left Steering Switch harness connector.

Measure the resistance between the (G206) EVIC MUX Signal 2 circuit and the (G907) EVIC/NAV MUX Return circuit at the Right Steering Switch harness connector.

Is the resistance approximately 10.00 Kohms (+/- 10%)?

Yes

- Replace the Left Steering Switch.

No

- Go to 5



5. RIGHT STEERING SWITCH

Replace the Right Steering Switch.

Reconnect the C206 (LIN Bus) connector.

Turn the ignition on.

Press and release the Audio Switch several times.

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

With the scan tool, select Data Display and view the Audio switch data.

While monitoring the Audio switch data, press and release the Audio Switch several times.

Does the Audio switch data change from Set to Not Set as the switch is pressed and released?

Yes

- Test Complete.

No

- Go to 6



6. STEERING CONTROL MODULE (SCM)

View repair.



Repair

- Replace the Steering Control Module (SCM).



7. INTERMITTENT STEERING WHEEL CONTROL AUDIO SWITCH CIRCUIT 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.