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 Diagram Set 71 (Escape/Mariner, Escape Hybrid/Mariner Hybrid), 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 circuit VLN04 (VT/GY) to the clockspring. The voltage passes through the clockspring to the steering wheel control switch harness and on to the steering wheel controls. Ground is supplied through the clockspring and circuit GD112 (BK/GN).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Steering wheel control switch harness
- Steering wheel control switch(es)
- 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.
- Are all the dimmable switches inoperative?

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

No
GO to D2.

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


- Depower the Supplemental Restraint System (SRS). Refer to Air Bag Systems.
- Disconnect: Clockspring C218.
- Connect: Negative Battery Cable.
- Ignition ON.
- 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 negative battery 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 GD112 (BK/GN) FOR AN OPEN


- Disconnect: Negative Battery Cable.
- Measure the resistance between the clockspring C218-7, circuit GD112 (BK/GN), 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 Connector.
- Measure the resistance between the clockspring C218 pin 2, component side and the upper clockspring connector pin 7, component side.




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




- Are the resistances less than 5 ohms?

Yes
GO to D5.

No
INSTALL a new clockspring. INSTALL the driver air bag module. TEST the system for normal operation.

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D5 CHECK THE STEERING WHEEL CONTROL SWITCH HARNESS


- Inspect the steering wheel control switch harness for shorts, opens, or any damage.
- Is the steering wheel control switch harness OK?

Yes
INSTALL new steering wheel controls. INSTALL the driver air bag module. TEST the system for normal operation.

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

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