Symptom Chart

Condition	Possible Sources	Action
No communication with the smart junction box (SJB)	Wiring, terminals or connectors SJB	REFER to MODULE COMMUNICATIONS NETWORK article.
The control illumination is inoperative - all hardwired dimmable illumination	Wiring, terminals or connectors Instrument panel dimmer switch SJB	Go to Pinpoint Test A .
The control illumination is inoperative - all non-dimmable illumination	Fuse Wiring, terminals or connectors SJB	Go to Pinpoint Test F .
The control illumination is always on - all hardwired illumination	Wiring, terminals or connectors SJB	Go to Pinpoint Test D .
All control illumination sources do not dim	Wiring, terminals or connectors Instrument panel dimmer switch SJB	Go to Pinpoint Test E .
All network-controlled illumination sources do not dim - hardwired illumination sources operate correctly	Medium speed communication area network (MS-CAN) fault SJB	Using the scan tool, CARRY OUT the network test. If the SJB does not communicate with the scan tool, REFER to MODULE COMMUNICATIONS NETWORK article. If the SJB does communicate with the scan tool, INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES article. TEST the system for normal operation.
One or more (but not all) individual dimmable illumination sources are inoperative	Wiring, terminals or connectors Illumination source Clockspring (steering wheel controls only) SJB	For the steering wheel controls, go to Pinpoint Test B . For all others, go to Pinpoint Test C .
One or more (but not all) non-dimmable illumination sources are inoperative	Wiring, terminals or connectors Illumination source SJB	Go to Pinpoint Test G .
The instrument cluster (IC) illumination is inoperative	IC SJB	VERIFY that the IC is the only inoperative network controlled illumination source. If the IC is the only inoperative network controlled illumination source, INSTALL a new IC. REFER to INSTRUMENT CLUSTER (IC), MESSAGE CENTER, AND WARNING CHIMES article. TEST the system for normal operation. If more than one network controlled illumination source is inoperative, INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES article. TEST the system for normal operation.
The audio control module (ACM) illumination is inoperative	ACM SJB	VERIFY that the ACM is the only inoperative network controlled illumination source. If the ACM is the only inoperative network controlled illumination source, INSTALL a new ACM. REFER to INFORMATION AND ENTERTAINMENT SYSTEMS article. TEST the system for normal operation. If more than one network controlled illumination source is inoperative, INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES article. TEST the system for normal operation.
The heating ventilation air conditioning (HVAC) module - electronic automatic temperature control (EATC) illumination is inoperative	HVAC module-EATC SJB	VERIFY that the HVAC module-EATC is the only inoperative network controlled illumination source. If the HVAC module-EATC is the only inoperative network controlled illumination source, INSTALL a new HVAC module-EATC. REFER to HVAC module in CLIMATE CONTROL article. TEST the system for normal operation. If more than one network controlled illumination source is inoperative, INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES article. TEST the system for normal operation.