Interior Lighting

INTERIOR LIGHTING
The interior lighting system consists of the following.
- Dome lamp
- Instrument panel dimmer switch
- Door ajar switch (located on both the front and rear door latches)
- Smart junction box (SJB)

Principles of Operation

Interior Lighting
When the smart junction box (SJB) detects a request for lighting, it turns on the interior lamp by supplying power to the lamp. The request for lighting can be a 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 door ajar switches are normally open when the doors are closed. All door ajar switches receive voltage from the SJB and each has its own ground circuit. The instrument panel dimmer switch receives voltage from the SJB and has its own ground circuit. The instrument panel dimmer switch provides variable resistance for backlighting the instrument cluster and a toggle on/off function for the courtesy lamp.

The inputs are:
- Ignition switch position
- LH front door ajar switch
- RH front door ajar switch
- LH rear door ajar switch
- RH rear door ajar switch
- RKE unlock signal

For additional door ajar switch information, see SECURITY AND LOCKS.

The output is:
- Interior lamp relay

Illuminated Entry (Option)
The illuminated entry feature requests the interior lamp on when the ignition switch is in the OFF position and the operator activates an external unlock feature (key fob or transmitter key pad). The illuminated entry feature requests the interior lamp off when: 25 seconds have elapsed, the ignition transitions out of the OFF position, or the customer activates an external lock feature.

The inputs are:
- Ignition switch position
- Unlock request to the RKE module The output is:
- Interior lamp relay

Demand Lamps
The demand lamp has its own switch and can be operated independently.
The demand lamps consist of a:
- Dome lamp

The demand lamp is also controlled by the interior lighting arbitrator and the interior lamp relay.

Interior Lighting Arbitrator
The interior lighting arbitrator decides between the interior lighting, the illuminated entry lighting, and the battery saver features to determine which feature has precedence for turning on and off the interior light. This feature is internal in the SJB.

The output is:
- Interior lamp relay

Battery Saver
When the ignition is off, the battery saver timer feature provides timed automatic shut-off of power to the interior lamp and the warning chimes. The battery saver has a time-out period of 5 minutes. The battery saver will restore power to the interior lamp or reset the 5 minute timer if any of the following interactions are detected:
- The ignition is turned to any position other than OFF.
- Any door becomes ajar.
- Any button of a remote or exterior device which provides access to the vehicle is pressed (key fob, keypad).

The inputs are:
- Ignition switch position
- LH front door ajar switch
- RH front door ajar switch
- LH rear door ajar switch
- RH rear door ajar switch
- Any request from the RKE key fob

The outputs are:
- Interior lamp relay
- WARNING chimes (internal to the instrument cluster)