Circuit Description

The Body Control Module (BCM) controls the interior illumination. The BCM turns on the interior courtesy lamps when the following actions occur.

• Any of the vehicle doors are opened.
• The dimmer switch is turned to the DOME position.
• Exit illumination is active.
• The doors are unlocked through the keyless entry system (BCM type 3 and type 4 only).
• The doors are unlocked using the door key cylinder (BCM type 4 only).

The BCM turns the interior lamps off when all the vehicle doors are closed and the dimmer switch is in the OFF position.

All the vehicle doors contain a door lock ajar switch. When the driver door is open, the left front door lock ajar switch closes and sends a ground signal to the BCM through the driver door switch signal circuit.

When one of the right front, left rear, or right rear doors is open, its corresponding door lock ajar switch closes and sends a ground signal to the BCM through the corresponding door ajar input circuit. The BCM grounds the courtesy lamps low control circuit when detecting a ground signal in any of the following circuits:

• Driver door switch signal circuit
• Sliding door switch signal circuit
• Door open switch signal circuit

When the driver door is closed, the left front door lock ajar switch opens the driver door switch signal circuit. When any door is closed, their corresponding door lock ajar switch opens the corresponding door switch signal circuit. The BCM opens the courtesy lamps low control circuit when all of the door switch signal circuits are open.

The BCM powers the interior lights through the courtesy lamps supply voltage circuit. The BCM deactivates the courtesy lamps supply voltage circuit during inadvertent load battery rundown protection. The BCM also opens the courtesy lamps low control circuit when the inadvertent battery power rundown protection is active.