Pinpoint Test E: The Courtesy Lamps Are Inoperative From The Instrument Panel Dimmer Switch

Interior Lighting

Pinpoint Tests

Pinpoint Test E: The Courtesy Lamps Are Inoperative From The Instrument Panel Dimmer Switch

Refer to Wiring Diagram Set 89, Interior Lamps for schematic and connector information. Diagrams By Number

Normal Operation

The Smart Junction Box (SJB) monitors the courtesy lamp request from the instrument panel dimmer switch on circuit CLN28 (GN/BU). Based on input from the instrument panel dimmer switch, the SJB supplies voltage to the courtesy lamps through circuit CLN26 (BU).

This pinpoint test is intended to diagnose the following:

- Dimmable backlighting illumination system concern
- Wiring, terminals or connectors
- Instrument panel dimmer switch
- SJB



PINPOINT TEST E: THE COURTESY LAMPS ARE INOPERATIVE FROM THE INSTRUMENT PANEL DIMMER SWITCH

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 THE DIMMABLE BACKLIGHTING ILLUMINATION


- Ignition OFF.
- Turn the headlamps switch to the PARKING LAMPS ON position.
- Rotate the instrument panel dimmer switch and observe the instrument cluster illumination.
- Does the instrument cluster illumination intensity agree with the instrument panel dimmer switch position?

Yes
GO to E2.

No
REFER to Instrument Panel, Gauges and Warning Indicators to continue diagnosis of the dimmable backlighting illumination.

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E2 CHECK THE INSTRUMENT PANEL DIMMER SWITCH


- Disconnect: Instrument Panel Dimmer Switch C2065.
- Connect a fused jumper wire between the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side and the instrument panel dimmer switch C2065-4, circuit CLN27 (WH/BN), harness side.




- Do the courtesy lamps illuminate?

Yes
REMOVE the jumper wire. INSTALL a new instrument panel dimmer switch. REFER to Instrument Panel, Gauges and Warning Indicators. TEST the system for normal operation.

No
REMOVE the jumper wire. GO to E3.

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E3 CHECK CIRCUIT CLN28 (GN/BU) FOR AN OPEN


- Disconnect: SJB C2280d.
- Measure the resistance between the SJB C2280d-26, circuit CLN28 (GN/BU), harness side and the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to E4.

No
REPAIR the circuit. TEST the system for normal operation.

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E4 CHECK FOR CORRECT SJB OPERATION


- Connect: Instrument Panel Dimmer Switch C2065.
- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new SJB. REFER to Body Control Systems. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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