Pinpoint Test C: The Steering Wheel Switch(es) Illumination Is Inoperative

Instrument Cluster and Panel Illumination

Pinpoint Test C: The Steering Wheel Switch(es) Illumination Is Inoperative

Refer to Wiring Diagram Set 71, Cluster and Panel Illumination for schematic and connector information Electrical Diagrams.

Normal Operation

When the parking lamps are on, the Body Control Module (BCM) sends voltage to the clockspring. The voltage passes through the clockspring to the steering wheel switches.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Steering wheel switch(es)

- Steering wheel harness

- Clockspring

PINPOINT TEST C : THE STEERING WHEEL SWITCH(ES) ILLUMINATION IS INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

C1 CHECK THE OTHER DIMMABLE LIGHTING SWITCHES

- Ignition ON.

- Place the headlamp switch in the PARKING LAMPS ON position.

- Press and hold the instrument panel dimmer switch up to the full illumination position and observe other dimmable switches.

Are all the dimmable steering wheel switches inoperative?

Yes
GO to Pinpoint Test A Pinpoint Test A: All Dimmable Non-Networked Illumination Is Inoperative.

No
If all the steering wheel switches illumination is inoperative GO to C2.

If only one steering wheel switch illumination is inoperative GO to C5.

C2 CHECK THE HORN OPERATION

- Press the driver airbag module against the steering wheel.

Does the horn sound?

Yes
GO to C3.

No
REFER to Horn to diagnose the horn is inoperative.

C3 CHECK FOR VOLTAGE TO THE STEERING WHEEL SWITCHES

- Place the headlamp switch in the OFF position.

- Remove the driver air bag module.

- Disconnect: Clockspring C218B.

- Ignition ON.

- Place the headlamp switch in the PARKING LAMPS ON position.

- Press and hold the instrument panel dimmer switch up to the full illumination position.

- Measure the voltage between the clockspring C218B-9, component side and the clockspring C218B-10, component side.






Is the voltage greater than 10 volts?

Yes
INSTALL a new steering wheel. TEST the system for normal operation.

No
GO to C4.

C4 CHECK FOR VOLTAGE TO THE CLOCKSPRING

- Disconnect: Clockspring C218A.

- Measure the voltage between the clockspring C218A-9, circuit VLN04 (VT/GY), harness side and the clockspring C218A-8, circuit GD115 (BK/GY), harness side.






Is the voltage greater than 10 volts?

Yes
INSTALL a new clockspring. TEST the system for normal operation.

No
REPAIR circuit VLN04 (VT/GY) for an open. TEST the system for normal operation.

C5 CHECK THE SUSPECT STEERING WHEEL SWITCH FOR VOLTAGE

- Remove the driver air bag module.

- Disconnect: Suspect Steering Wheel Switch.

- Press and hold the instrument panel dimmer switch up to the full illumination position.

- Measure the voltage between the inoperative illumination source, harness side as follows:

Component Connector-Pin Connector-Pin Steering wheel switch- LH C2998-10 C2998-5 Steering wheel switch- RH C2999-6 C2999-1 Paddle Shift switch- LH (if equipped) C2429-1 C2429-2 Paddle Shift switch- RH (if equipped) C2428-4 C2428-3






Is the voltage greater than 10 volts?

Yes
INSTALL a new component in question. TEST the system for normal operation.

No
INSTALL a new steering wheel. TEST the system for normal operation.