Pinpoint Test A: The Control Illumination Is Inoperative - All Hardwired Illumination
Instrument Cluster and Panel Illumination
Pinpoint Tests
Pinpoint Test A: The Control Illumination Is Inoperative - All Hardwired Illumination
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) sends a Pulse Width Modulated (PWM) voltage to the dimmable components through circuit VLN04 (VT/GY). Ground is provided through circuits GD111 (BK/BU), GD133 (BK), and GD147 (BK/VT).
- DTC B2A32 (LED Backlighting Output Circuit Open) - an on-demand DTC that sets when the SJB detects an open on the backlighting output circuit.
- DTC B2A33 (LED Backlighting Output Circuit Short To Ground) - a continuous and on-demand DTC that sets when the SJB detects a short to ground on the backlighting output circuit. The DTC also sets as a result when fuse 10 (15A) has failed or is removed.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Instrument panel dimmer switch
- SJB
PINPOINT TEST A: THE CONTROL ILLUMINATION IS INOPERATIVE - 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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A1 CHECK FOR RECORDED SJB DTCs FROM THE ON-DEMAND SELF-TEST
- Use the recorded results from the SJB self-test.
- Is DTC B2A32 or B2A33 recorded?
Yes
GO to A3.
No
GO to A2.
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A2 CHECK THE INSTRUMENT PANEL DIMMER SWITCH
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Monitor the SJB dimmer switch PID (DIM_SW_3) while rotating the instrument panel dimmer switch from the lowest setting to the highest setting.
- Does the PID indicate the switch is operating correctly?
Yes
GO to A4.
No
INSTALL a new instrument panel dimmer switch. REFER to Instrument Panel Dimmer Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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A3 CHECK THE ILLUMINATION OUTPUT CIRCUIT VLN04 (VT/GY)
NOTE: If the fuse in the jumper wire fails, Refer to the Wiring Diagrams to identify the possible causes of the short circuit.
- Ignition OFF.
- Disconnect: SJB C2280b.
- Connect a fused jumper wire between the SJB C2280b-39, circuit VLN04 (VT/GY) and battery positive.
- Do the backlighting components illuminate?
Yes
REMOVE the jumper wire. GO to A4.
No
REMOVE the jumper wire. VERIFY the SJB fuse 10 (15A) is OK. REPAIR the circuit. RUN the on-demand self-test (required to clear certain DTCs). CORRECT any unresolved DTCs.
CLEAR all DTCs. TEST the system for normal operation.
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A4 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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