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

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test C: 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

When the headlamp switch is placed in the PARKING or HEADLAMP ON position, the Smart Junction Box (SJB) supplies either a Pulse-Width Modulation (PWM) signal or 12 volts to the various backlighting sources in the instrument panel, doors and console.

- DTC B2027 (LED Backlighting Output Circuit Failure) - is a continuous and on-demand DTC that sets when the SJB detects a short to voltage on the LED backlighting circuits.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- SJB



PINPOINT TEST C: 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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C1 CHECK FOR RECORDED SJB DTCs FROM THE ON-DEMAND SELF-TEST


- Use the recorded results from the SJB self-test.
- Is DTC B2027 recorded?

Yes
GO to C2.

No
GO to C3.

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C2 CHECK CIRCUITS 1403 (BK/WH), 19 (LB/RD), 293 (OG/RD), 203 (OG/LB), 2023 (YE/LB), 2030 (YE/WH) AND 1425 (GY/WH) FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: SJB C2280b.
- Disconnect: SJB C2280e.
- Disconnect: SJB C2280f.
- Ignition ON.
- Do the dimmable backlighted components continue to illuminate?

Yes
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.

No
GO to C3.

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C3 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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