Pinpoint Test D: The Steering Wheel Switch Illumination Is Inoperative

Instrument Cluster and Panel Illumination

Pinpoint Test D: The Steering Wheel Switch Illumination Is Inoperative

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

Normal Operation

The Smart Junction Box (SJB) provides voltage to the steering wheel switches based on input from the instrument panel dimmer switch. The voltage passes through the clockspring to the steering wheel harness and then to the steering wheel switches.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Steering wheel harness
- Steering wheel switches
- Clockspring

PINPOINT TEST D: THE STEERING WHEEL SWITCH 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.

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D1 CHECK THE OTHER DIMMABLE LIGHTING SWITCHES

- Ignition OFF.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Rotate the instrument panel dimmer switch to the full illumination position and observe other dimmable switches.
- Are all the dimmable switches inoperative?

Yes
GO to Pinpoint Test B. Pinpoint Test B: All Dimmable Switch Illumination Is Inoperative

No
GO to D2.

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D2 CHECK FOR VOLTAGE TO THE CLOCKSPRING

- Place the headlamp switch in the OFF position.
- Depower the Supplemental Restraint System (SRS). Refer to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Clockspring C218a.
- Connect: Negative Battery Cable.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Increase the backlighting brightness to the highest setting.
- Measure the voltage between the clockspring C218a-16, circuit VLN37 (BU/WH), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to D3 .

No
REPAIR circuit VLN37 (BU/WH) for an open. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering. TEST the system for normal operation.

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D3 CHECK THE CLOCKSPRING GROUND FOR AN OPEN

- Measure the voltage between the clockspring C218a-16, circuit VLN37 (BU/WH), harness side and the clockspring C218a-5, circuit GD114 (BK/BU), harness side.




- Is the voltage greater than 10 volts?

Yes
GO to D4.

No
REPAIR circuit GD114 (BK/BU) for an open. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering. TEST the system for normal operation.

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D4 CHECK THE CLOCKSPRING FOR AN OPEN

- Remove the driver air bag module. Refer to Supplemental Restraint System Driver Air Bag Module.
- Disconnect: Upper Clockspring C218b.
- Measure the resistance between the clockspring C218a pin 5, component side and the upper clockspring C218b pin 4, component side.




- Measure the resistance between the clockspring C218a pin 16, component side and the upper clockspring C218b pin 7, component side.




- Are the resistances less than 5 ohms?

Yes
INSTALL a new steering wheel. REFER to Steering Column Removal and Replacement. TEST the system for normal operation.

No
INSTALL a new clockspring. INSTALL the driver air bag module. REFER to Supplemental Restraint System Driver Air Bag Module. TEST the system for normal operation.

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