Pinpoint Test B: The Control Illumination Is Always On - All Hardwired Illumination

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test B: The Control Illumination Is Always On - All Hardwired Illumination

Refer to Wiring Diagram Set 71, Cluster and Panel Illumination for schematic and connector information. Diagrams By Number

Normal Operation

Based on input received from the instrument panel dimmer switch, the Smart Junction Box (SJB) sends a Pulse Width Modulated (PWM) voltage to the hardwired dimmable illumination sources through circuit VLN37 (BU/WH).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- SJB



PINPOINT TEST B: THE CONTROL ILLUMINATION IS ALWAYS ON - ALL HARDWIRED ILLUMINATION

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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B1 CHECK THE EXTERIOR LIGHTING


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

Yes
REFER to Lighting and Horns. Lighting and Horns

No
GO to B2.

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B2 CHECK CIRCUIT VLN37 (BU/WH) FOR A SHORT TO VOLTAGE


- Disconnect: SJB C2280b.
- Ignition ON.
- Do the dimmable backlighted components continue to illuminate?

Yes
REPAIR the short to voltage. CLEAR the DTCs. REPEAT the self-test.

No
GO to B3.

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B3 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. 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. CLEAR the DTCs. REPEAT the self-test.

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