Pinpoint Test D: The Steering Wheel Control Illumination Is Inoperative

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test D: The Steering Wheel Control Illumination Is Inoperative

Refer to Wiring Diagrams 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 voltage to the steering wheel controls through circuit VLN04 (VT/GY) to the clockspring. The voltage passes through the clockspring to the steering wheel harness and on to the steering wheel control switches. Ground is provided through the clockspring and circuit GD134 (BK/VT).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Steering wheel control switch
- Steering wheel harness
- Clockspring



PINPOINT TEST D: THE STEERING WHEEL CONTROL 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.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.

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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 (headlamp switch for example).
- Are all the dimmable switches inoperative?

Yes
Go To Pinpoint Test A. Pinpoint Test A: The Control Illumination Is Inoperative

No
GO to D2.

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D2 CHECK CIRCUIT VLN04 (VT/GY) FOR AN OPEN


- Place the headlamp switch in the OFF position.
- Depower the Supplemental Restraint System (SRS). Refer to Air Bag Systems.
- Disconnect: Clockspring C218.
- Connect: Negative Battery Cable.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the clockspring C218-2, circuit VLN04 (VT/GY), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
TURN the headlamp switch off. GO to D3.

No
DISCONNECT the battery ground cable. REPAIR the circuit. REPOWER the SRS. REFER to Air Bag Systems. TEST the system for normal operation.

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D3 CHECK CIRCUIT GD134 (BK/VT) FOR AN OPEN


- Disconnect: Negative Battery Cable.
- Measure the resistance between the clockspring C218-7, circuit GD134 (BK/VT), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to D4.

No
REPAIR the circuit. REPOWER the SRS. REFER to Air Bag Systems. TEST the system for normal operation.

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D4 CHECK THE CLOCKSPRING FOR AN OPEN


- Remove the driver air bag module.
- Disconnect: Upper Clockspring.
- Measure the resistance between the clockspring C218 pin 2, component side and the upper clockspring pin 7, component side.




- Measure the resistance between the clockspring C218 pin 7, component side and the upper clockspring pin 4, component side.




- Are the resistances less than 5 ohms?

Yes
GO to D5.

No
INSTALL a new clockspring. TEST the system for normal operation.

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D5 CHECK THE STEERING WHEEL HARNESS


- Disconnect: Steering Wheel Control Switches.
- Inspect the steering wheel harness for damage or shorts.
- Is the steering wheel harness OK?

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

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

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