Horn Switch Stuck - With EVIC

B2339-HORN SWITCH STUCK - WITH EVIC

For a complete wiring diagram refer to the Wiring Information. Electrical Diagrams

Theory of Operation

The Horn Switch is connected 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 Interior BUS 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 Horn Switch is in the Set position for greater than 50 seconds.





1. DTC IS ACTIVE
1. Ignition on, engine not running.
2. 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

- 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.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. (X3) HORN SWITCH SENSE CIRCUIT SHORT TO (X920) RADIO CONTROL MUX RETURN CIRCUIT




1. Turn the ignition off.
2. Remove the Driver Airbag.
3. Disconnect the Horn Switch harness connector.
4. Disconnect the Right Steering Switch harness connector.

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

5. Measure the resistance between the (X3) Horn Switch Sense circuit and the (X920) Radio Control Mux Return circuit.

Is the resistance below 5.0 ohms?

Yes

- Repair the (X3) Horn Switch Sense circuit for a short to the (X920) Radio Control Mux Return circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. (X3) HORN SWITCH SENSE CIRCUIT SHORT TO GROUND





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

1. Measure the resistance between the (X3) Horn Switch Sense circuit at the harness connector to the Right Switch and ground (include the metal casing at the back side of the Airbag).

Is the resistance below 5.0 ohms?

Yes

- Repair the (X3) Horn Switch Sense circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. HORN SWITCH
1. Measure the resistance between the (X3) Horn Switch circuit and the (X920) Radio Control Mux Return circuit at the harness connector to the horn switch.

Is the resistance below 5.0 ohms?

Yes

- Replace the Horn Switch.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 5

5. RIGHT STEERING SWITCH
1. Turn the ignition off.
2. Replace the Right Steering Switch.
3. Turn the ignition on.
4. Press and release the Horn Switch several times.
5. With the Scan Tool, Clear Stored DTCs in the Steering Control Module.
6. With the Scan Tool, select Data Display and view the Horn switch data.
7. While monitoring the Horn switch data, press and release the Horn Switch several times.

Does the Horn switch data change from Set to Not Set when the switch is pressed and released?

Yes

- Test Complete.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

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