Symptom Chart

SYMPTOM CHART

Condition	Possible Sources	Action
All dimmable illumination is inoperative	Wiring, terminals or connectors Instrument panel dimmer switch Smart Junction Box (SJB)	GO to PINPOINT TEST A .
NOTE: This symptom also diagnoses the auxiliary climate control assembly for Navigator. All dimmable switch illumination is inoperative	Fuse Wiring, terminals or connectors Auxiliary climate control assembly (Navigator) SJB	GO to PINPOINT TEST B .
All dimmable switch illumination is always on	Wiring, terminals or connectors SJB	GO to PINPOINT TEST C .
All dimmable illumination does not dim	Wiring, terminals or connectors Instrument panel dimmer switch SJB	GO to PINPOINT TEST D .
The window control switch illumination is inoperative - Expedition only	Window control switch	CHECK the operation of the power windows. If the power windows operate correctly, INSTALL a new window control switch. REFER to GLASS, FRAMES AND MECHANISMS . TEST the system for normal operation. If the power windows do not operate correctly, REFER to GLASS, FRAMES AND MECHANISMS .
The steering wheel switch illumination is inoperative	Wiring, terminals or connectors Steering wheel switch(es) Steering wheel harness Clockspring	GO to PINPOINT TEST E .
One or more switch illumination is inoperative	Wiring, terminals or connectors Adjustable pedal switch Ashtray receptacle (Navigator) Auxiliary climate control assembly Clock (Navigator) Door lock control switch(es) Floor shifter Four-Wheel Drive (4WD) mode select switch Headlamp switch Message center switch Overhead console Power liftgate/traction control/hazard switch Window control switch(es) (Navigator) SJB	GO to PINPOINT TEST F .
All network controlled illumination does not dim	Medium Speed Controller Area Network(MS-CAN) SJB	CARRY OUT the network test. If the scan tool responds with no communication with the SJB, REFER to MODULE COMMUNICATIONS NETWORK . If the scan tool communicates with the SJB, INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES . TEST the system for normal operation.
The Instrument Cluster (IC) illumination is inoperative/does not dim	MS-CAN IC	CARRY OUT the network test. If the scan tool responds with no communication with the IC, REFER to MODULE COMMUNICATIONS NETWORK . If the scan tool communicates with the IC, INSTALL a new IC. REFER to INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES . TEST the system for normal operation.
The Audio Control Module (ACM) illumination is inoperative/does not dim	MS-CAN ACM	CARRY OUT the network test. If the scan tool responds with no communication with the ACM, REFER to MODULE COMMUNICATIONS NETWORK . If the scan tool communicates with the ACM, INSTALL a new ACM. REFER to INFORMATION AND ENTERTAINMENT SYSTEMS . TEST the system for normal operation.
The HVAC module illumination is inoperative/does not dim	MS-CAN HVAC module	CARRY OUT the network test. If the scan tool responds with no communication with the HVAC module, REFER to MODULE COMMUNICATIONS NETWORK . If the scan tool communicates with the HVAC module, INSTALL a new HVAC module. REFER to CLIMATE CONTROL . TEST the system for normal operation.
The Rear Entertainment Module (RETM) illumination is inoperative/does not dim	MS-CAN RETM	CARRY OUT the network test. If the scan tool responds with no communication with the RETM, REFER to MODULE COMMUNICATIONS NETWORK . If the scan tool communicates with the RETM, INSTALL a new RETM. REFER to INFORMATION AND ENTERTAINMENT SYSTEMS . TEST the system for normal operation.