Courtesy Lamp: Description and Operation

GENERAL INFORMATION
The Body Control Module (BCM) illuminates the courtesy lamps whenever a door is opened. When the last door is closed, the BCM "fades-to-OFF" the courtesy lamps in five seconds. If a door is left ajar, the courtesy lamps remain on for a maximum of one hour when ignition switch is OFF. After one hour, the BCM "fades-to-OFF" the courtesy lamps.

NOTE: If the dome lamp switch is in the ON position, the BCM will not turn oft the dome lamp. This switch is connected directly to the lamp.

CIRCUIT OPERATION
Overhead Map/Courtesy Lamps
The overhead map/courtesy lamps are powered by the 10 amp fuse, located in the junction block, on the M1 circuit. This fuse is the Ignition-Off Draw (IOD) fuse and is located in cavity 13. This circuit is HOT at all times.

Ground for the lamps is provided in three ways.

One way is when the operator turns the lamp ON by CLOSING the switch. A ground path is completed on circuit Z1. This ground terminates at the Airbag Control Module (ACM) bracket.

The second way is when any door is opened through the Body Control Module (BCM) and the door ajar switches. When the door is OPENED, the door ajar switch CLOSES completing a path to ground. The BCM then process this information and grounds the M2 circuit, which is the ground circuit for the lamps.

The third way is through the dimmer control switch in the instrument panel. When the dimmer control is moved to the high end of travel, past the detent, the interior lamps and map/courtesy lamps are turned ON. This is accomplished when the switch in the control is CLOSED connecting circuits L7 and M32. Circuit M32 connects from the switch to the BCM.

The BCM, after receiving this input from the switch, grounds the M2 circuit. The M2 circuit is spliced and connects to all the interior lamps and the door courtesy lamps.

Rear Reading/Courtesy Lamps
The rear reading/courtesy lamps are powered by the 10 amp fuse, located in the junction block, on the M1 circuit. This fuse is the Ignition-Off Draw (IOD) fuse and is located in cavity 13. This circuit is HOT at all times.

Ground for the lamps is provided in three ways.

One way is when the operator turns the lamp ON by closing the switch. A ground path is completed on circuit Z1. This ground terminates at the Airbag Control Module (ACM) bracket. Base vehicles are not equipped with a switch.

The second way is when any door is opened through the Body Control Module (BCM) and the door ajar switches. When the door is opened, the door ajar switch CLOSES completing a path to ground. The BCM then process this information and grounds the M2 circuit, which is the ground circuit for the lamps.

The third way is through the dimmer control switch in the instrument panel. When the dimmer control is moved to the high end of travel, past the detent, the interior lamps and map/courtesy lamps are turned ON. This is accomplished when the switch in the control is CLOSED connecting circuits L7 and M32. Circuit M32 connects from the switch to the BCM.

The BCM, after receiving this input from the switch, grounds the M2 circuit. The M2 circuit is spliced and connects to all the interior lamps and the rear courtesy lamps.