For 1990-2009 cars

By using a feature called inadvertent power control, the body control module (BCM) supplies power to all of the following components:

• | The courtesy lamps

• | The dome lamps

• | The rear view mirror reading lamps

• | The instrument panel compartment lamp

• | The rear compartment lamp

The left front door ajar switch turns the interior lamps on through the BCM by grounding CKT 394. When the left front door is open, the switch is closed. This condition provides a ground and a door open input to the BCM. The BCM then grounds the following lamps through CKT 156 in order to turn the lamps on:

• | The courtesy lamps

• | The dome lamp

• | The rearview mirror lamps

The right front door ajar switch and the rear door ajar switches turn the interior lamps on by grounding CKT 395 from the BCM.

When the ignition key is removed from the lock cylinder, the interior lamps remain on for approximately 40 seconds.

The BCM provides an interior lamps-on delay after a door is opened. The lamps remain on for approximately 40 seconds or until the ignition switch is turned to the ON position. The 40 second lamps-on delay reduces to 4 seconds if a door is opened within 2 minutes of the ignition switch being moved from the ON position. The interior lamps immediately turn off when the vehicle begins to move.

The dome lamp OFF-DOOR-ON switch controls the dome lamp. When the switch is in the OFF position, the dome lamp remains off. When the switch is in the DOOR position, the dome lamp lights when a door is opened by the BCM grounding CKT 156. When the switch is in the ON position, ground is supplied through CKT 750. The rear view mirror reading lamps are controlled by the rear view mirror reading lamps switch or through CKT 156 from the BCM.

Voltage is supplied at all times to the BCM through the INT LPS fuse. The BCM supplies voltage to the interior lamps through CKT 1732.

### Battery Run Down Protection

When the ignition switch is in the OFF position, the BCM turns off the power to all of the interior lamps after 18-22 minutes.

The BCM will reset the inadvertent power control relay output when one of the following actions is performed:

• | Open or close a door.

• | Turn the ignition switch to the ON position.

• | Turn off any interior lamps that may be on.

• | Press the power door lock switch/keyfob button.

• | Press the decklid release keyfob button.