Pinpoint Test E: The Steering Wheel Switch Illumination Is Inoperative

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test E: 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 voltage to the steering wheel switches for illumination. The voltage passes through the clockspring to the steering wheel harness and on 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 E: 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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E1 CHECK FOR VOLTAGE TO THE CLOCKSPRING


- Ignition OFF.
- 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.
- Rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the clockspring C218a-16, circuit CLN04 (BU/BN), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
TURN the parking lamps off. GO to E2.

No
REPAIR circuit CLN04 (BU/BN) for an open. REPOWER the SRS. REFER to Restraint Systems. TEST the system for normal operation.

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E2 CHECK FOR VOLTAGE TO THE CLOCKSPRING USING THE CONNECTOR GROUND


- Measure the voltage between the clockspring C218a-16, circuit CLN04 (BU/BN), harness side and the clockspring C218a-5, circuit GD143 (BK/VT), harness side.




- Is the voltage greater than 10 volts?

Yes
GO to E3.

No
REPAIR circuit GD143 (BK/VT) for an open. REPOWER the SRS. REFER to Restraint Systems. TEST the system for normal operation.

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E3 CHECK THE CLOCKSPRING FOR AN OPEN


- Remove the driver air bag module. Refer to Restraint Systems.
- Disconnect: Upper Clockspring C218b.
- Measure the resistance between the clockspring C218a pin 16, component side and the upper clockspring C218b pin 7, component side.




- Measure the resistance between the clockspring C218a pin 5, component side and the upper clockspring C218b pin 4, component side.




- Are the resistances less than 5 ohms?

Yes
GO to E4.

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

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E4 CHECK THE STEERING WHEEL HARNESS


- Disconnect: Steering Wheel Switch C203 and Audio/Climate Control Switch C2208.
- Measure the resistance between the upper clockspring, harness side, and the steering wheel switch as follows:









- Are the resistances less than 5 ohms?

Yes
INSTALL a new steering wheel switch. REFER to Fire Suppression System or Accessories and Optional Equipment 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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