Pinpoint Test D: The Steering Wheel Switch Illumination Is Inoperative

Instrument Cluster and Panel Illumination

Pinpoint Tests

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) sends a Pulse Width Modulated (PWM) voltage to the steering wheel controls through 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 harness
- Steering wheel switch(es)
- 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.
- Push the instrument panel dimmer switch to the full illumination position and observe the 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 Restraint Systems.
- Disconnect: Clockspring C218a.
- Connect: Negative Battery Cable.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Push the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the clockspring C218a-16, circuit VLN04 (VT/GY), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to D3.

No
REPAIR circuit VLN04 (VT/GY) for an open. REPOWER the SRS. REFER to Restraint Systems. TEST the system for normal operation.

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D3 CHECK FOR VOLTAGE TO THE CLOCKSPRING USING THE CONNECTOR GROUND


- Measure the voltage between the clockspring C218a-16, circuit VLN04 (VT/GY), harness side and the clockspring C218a-5, circuit GD116 (BK/VT), harness side.




- Is the voltage greater than 10 volts?

Yes
GO to D4.

No
REPAIR circuit GD116 (BK/VT) for an open. REPOWER the SRS. REFER to Restraint Systems. 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 Restraint Systems.
- Disconnect: Upper Clockspring Connector.
- Measure the resistance between the clockspring C2274 pin 5, component side and the upper clockspring connector pin 4, component side.




- Measure the resistance between the clockspring C2274 pin 16, component side and the upper clockspring connector pin 7, component side.




- Are the resistances less than 5 ohms?

Yes
GO to D5.

No
INSTALL a new clockspring. REFER to Restraint Systems. TEST the system for normal operation.

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D5 CHECK THE STEERING WHEEL HARNESS


- Inspect the steering wheel harness for opens.
- Is the steering wheel harness OK?

Yes
INSTALL a new steering wheel control switch. REFER to Fire Suppression System (cruise control switch) or Accessories and Optional Equipment (audio control switch) as necessary. INSTALL the driver air bag module. REFER to Restraint Systems. TEST the system for normal operation.

No
REPAIR or INSTALL a new steering wheel harness. INSTALL the driver air bag module. REFER to Restraint Systems. TEST the system for normal operation.

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