The interior lighting system consists of 2 subsystems
- Courtesy lamps
- Demand lamps
The courtesy lamps are controlled by the smart junction box (SJB). The courtesy lamp subsystem consists of the interior dome lamps. The SJB controls the courtesy lamps by providing power to the lamps. The SJB also provides the ground circuit for the courtesy lamps. The courtesy lighting feature will request the courtesy lamps to be illuminated when any of the vehicle doors are opened or become ajar and the vehicle speed is less than 15 km/h (9 mph). The courtesy lamps will turn off, when the doors are closed or the vehicle speed reaches 15 km/h (9 mph). The courtesy lamps can also be turned on by rotating the instrument panel dimmer switch to the highest point. The theatre dimming option raises the courtesy lamps over 0.7 seconds when courtesy lamp activation is requested, and lowers the courtesy lamps over 1.7 seconds when courtesy lighting deactivation is requested.
The demand lamp subsystem consists of the map lamps and the luggage compartment lamp. Map lamps are switched individually and share a common ground circuit. The luggage compartment lamp is illuminated when the trunk is opened.
The bussed electrical center (BEC) supplies power to the interior lighting system through the SJB. The SJB will set DTCs if certain circuit failures exist with the interior lighting system.
Refer to INTERIOR LIGHTS for schematic and connector information.
SPECIAL TOOL CHART 73III Automotive Meter 105-R0057 or equivalent Worldwide Diagnostic System (WDS) Vehicle Communication Module (VCM) with appropriate adapters, or equivalent diagnostic tool
Principles of Operation
When the smart junction box (SJB) detects a request for lighting, it turns on the interior lamps by supplying power to the lamps. The request for lighting can be an open door signal from a door ajar switch, an interior lighting on command from the instrument panel dimmer switch or an unlock command from a remote keyless entry (RKE) transmitter.
The door ajar switches are hard-wired directly to the SJB. The 2 door ajar switches are normally closed when the doors are closed. The luggage compartment lid ajar switch is normally closed when the luggage compartment lid is closed. All door ajar switches receive voltage from the SJB and each has its own ground circuit.
The instrument panel dimmer switch receives a ground signal from the SJB. The instrument panel dimmer switch provides variable resistance for backlighting the instrument cluster and a toggle on/off function for the courtesy lamps.
The RKE receiver is contained inside the SJB. When the SJB receives an unlock request from an RKE transmitter, it unlocks the doors and turns on the courtesy lamps.
Normal Operation
Power is supplied to the courtesy lamps through the bussed electrical center (BEC) fuse 67 (30A) to the smart junction box (SJB). When a door is opened, the ajar switch opens, signaling the SJB. The SJB monitors the ajar circuits, and based on the ajar status, the SJB will supply voltage to the courtesy lamps on circuit 53 (BK/LB). Ground for the courtesy lamps is supplied by the SJB through circuit 54 (LG/YE).
When a door is open, the ajar switch opens the circuit to the smart junction box (SJB). The SJB monitors the ajar circuits, and based on the ajar status, the SJB will supply voltage to the courtesy lamps on circuit 53 (BK/LB).
The smart junction box (SJB) monitors the dimmer control switch status on circuit 2085 (VT/YE) to determine if the courtesy lamps are requested. Based on the dimmer control switch status, the SJB supplies voltage to the courtesy lamps through circuit 53 (BK/LB).
When a door is opened, the door ajar circuits 1312 (LG/BK) or 1314 (YE/GN) to the smart junction box (SJB) open. When the SJB identifies that the circuit is open, the SJB provides voltage to the courtesy lamps through circuit 53 (BK/LB). The door ajar switches are grounded through circuit 1205 (BK). When the dimmer control switch is rotated to the interior lamps ON position, the SJB receives a signal through circuit 2085 (VT/YE) requesting the courtesy lamps.
The smart junction box (SJB) provides voltage to the demand lamps through circuit 53 (BK/LB). Ground for the demand lamps is provided through circuit 1205 (BK).
When the luggage compartment lid is open, circuit 1351 (TN) to the smart junction box (SJB) opens. When the SJB identifies that the circuit is open, the SJB provides voltage to the luggage compartment lamp through circuit 707 (WH/YE). The luggage compartment lid ajar switch is grounded through circuit 1205 (BK).
When the luggage compartment lid is open, circuit 1351 (TN) to the smart junction box (SJB) opens. When the SJB identifies that the circuit is open, the SJB provides voltage to the luggage compartment lamp through circuit 707 (WH/YE). The luggage compartment lid ajar switch is grounded through circuit 1205 (BK).
The illuminated entry provides courtesy lighting whenever the smart junction box (SJB) receives a doors unlock request from the RKE transmitter. The SJB provides voltage on circuit 53 (BK/LB) for the courtesy lamps.
See also:
• COMPONENT TESTING