Inspection and Verification

Visually inspect for obvious signs of mechanical or electrical damage.

VISUAL INSPECTION CHART

Mechanical	Electrical
Instrument panel dimmer switch	Smart junction box (SJB) fuse 6 (5A) Miniature bulb(s) Circuitry Accessory delay relay Instrument cluster Headlamp switch

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
If the cause is not visually evident, connect the diagnostic tool to the data link connector (DLC) and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
- check that the program card is correctly installed.
- check the connections to the vehicle.
- check the ignition switch position.
If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
Carry out the diagnostic tool data link test. If the diagnostic tool responds with:
- CAN circuits fault; all electronic control units no response/not equipped, refer to MODULE COMMUNICATIONS NETWORK .
- No response/not equipped for the SJB, refer to MULTIFUNCTION ELECTRONIC MODULES .
- No response/not equipped for the instrument cluster, refer to INSTRUMENT CLUSTER .
- System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs, and carry out self-test diagnostics for the SJB and the instrument cluster.
If the DTCs retrieved are related to the concern and are from the SJB, go to the SMART JUNCTION BOX (SJB) DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
If the DTCs retrieved are related to the concern and are from the instrument cluster, refer to INSTRUMENT CLUSTER .
If no DTCs related to the concern are retrieved, GO to SYMPTOM CHART .

SMART JUNCTION BOX (SJB) DIAGNOSTIC TROUBLE CODE (DTC) INDEX

DTC	Description	Source	Action
B1247	Instrument Panel Dimmer Switch Circuit Open	SJB	GO to PINPOINT TEST B .
B1342	ECU is Faulted	SJB	DOCUMENT and CLEAR the DTCs. REPEAT the self-test. If DTC B1342 is retrieved again, INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES .
B2027	LED Backlighting Output Circuit Failure	SJB	GO to PINPOINT TEST C .
B2132	Dimmer Switch Circuit Short To Ground	SJB	GO to PINPOINT TEST B .
B2477	Module Configuration Failure	SJB	DOCUMENT and CLEAR the DTCs. REPEAT the self-test. If DTC B2477 is retrieved again, REFER to MODULE CONFIGURATION .
U1900	CAN Communication Bus Fault - Receive Error	SJB	DOCUMENT and CLEAR the DTCs. REPEAT the self-test. If DTC U1900 is retrieved again, REFER to MODULE COMMUNICATIONS NETWORK .
All Other DTCs	-	SJB	REFER to MULTIFUNCTION ELECTRONIC MODULES .