Pinpoint Test D: All Dimmable Switch Illumination Does Not Dim

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test D: All Dimmable Switch Illumination Does Not Dim

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) supplies a pulse-width modulated voltage signal to the dimmable illumination sources on 2 separate circuits, based on input from the instrument panel dimmer switch when the parking lamps are on.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- SJB



PINPOINT TEST D: ALL DIMMABLE SWITCH ILLUMINATION DOES NOT DIM

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 EXTERIOR LIGHTING


- Ignition OFF.
- Place the headlamp switch in the OFF position.
- Observe the exterior lighting components.
- Are any exterior lighting components illuminated?

Yes
REFER to Lighting and Horns.

No
GO to D2.

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D2 CHECK THE DIMMABLE LIGHTING OUTPUT FOR A SHORT TO VOLTAGE


- Disconnect: SJB C2280c.
- Ignition ON.
- Do any dimmable backlighting components continue to illuminate?

Yes
REPAIR circuit CLN04 (BU/BN) for a short to voltage. TEST the system for normal operation.

No
GO to D3.

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D3 CHECK FOR CORRECT SJB OPERATION


- 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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