Battery positive voltage (B+) is applied at all times through the INDVERT Fuse to the switch side of the inadvertent power relay. Battery positive voltage (B+) is also applied at all times through the MIRROR Fuse to the coil side of the inadvertent power relay. When the ignition switch is turned to the RUN position, the body control module (PZM) will activate the inadvertent power relay by grounding the relay coil via CKT 247 (BRN). When the inadvertent power relay is active, battery positive voltage (B+) is supplied via CKT 65 (PPL) to the underhood fuse block INT LPS Fuse, CIG LTR 1 Fuse, and CIG LTR 2 Fuse. The PZM will deactivate the inadvertent power relay ten minutes after the ignition switch is removed from the RUN position. With the ignition switch in the OFF or ACCY position, the PZM will also deactivate the inadvertent power relay ten minutes after any of the following conditions occur:

The instrument cluster monitors the ambient light conditions through the ambient light sensor. The ambient light sensor is a variable resistor whose resistance changes as the ambient light level around it changes. As the ambient light decreases, the resistance of the ambient light increases. The value of the input voltage will be between 0 and 5 volts. The voltage level at the instrument cluster light input increases as the ambient light sensor resistance increases.

When the ambient light sensor indicates darkness, the illuminated entry activates the courtesy lamps when the keyless entry transmitter is used to unlock the vehicle, when a front door is unlocked using a key, or a door is opened. After unlocking the vehicle with the keyless entry transmitter or unlocking a front door using a key, the PZM will turn on the courtesy lamps for twenty seconds with no other inputs. The courtesy lamps will remain ON for 20 seconds after all of the doors are closed. The PZM controls the time delay. If the ignition switch is turned to the RUN position before twenty seconds has elapsed, the PZM will immediately turn OFF the courtesy lamps.

Battery positive voltage (B+) is applied during inadvertent power through the INT LPS Fuse to the courtesy lamps and the coil side of the courtesy relay. When the PZM receives a signal to activate the courtesy lamps, ground is provided for the coil of the courtesy relay. The coil is energized, closing the switch contacts. Ground is then provided via CKT 1495 (DK BLU/WHT) for the courtesy lamps. The lamps will then illuminate.

The body control module (PZM) controls the following:

The door position is monitored through the door lock actuators by the PZM. When a door is opened, the respective door lock actuator closes and grounds the door open input to the PZM. When a door is closed, the door lock actuator opens and removes ground from the PZM. When a front door is manually unlocked, the respective door lock cylinder switch closes and grounds the door unlock input to the PZM.

The courtesy lamps can be turned on by the interior lamp switch regardless of ambient light conditions, door position, or ignition state. When the interior lamps switch is enabled, the instrument cluster interior lamps switch input is grounded through the headlamp switch. In response to this input, the instrument cluster sends a request via the Class 2 serial data line to the PZM to activate the courtesy lamps.

The PZM receives a Class 2 message from the remote function actuator (RFA) when the keyless entry transmitter is used to unlock the vehicle.

Some courtesy/reading lamps may be turned on by pressing the lamp. When this is done, the courtesy/reading lamp switch grounds the lamp to G401 via CKT 1250 (BLK). The lamps will only illuminate when battery positive voltage (B+) is being supplied during inadvertent power through the INT LP Fuse.

The PZM will activate the courtesy lamps 15 seconds after receiving a message that the airbags have been deployed. The courtesy lamps will deactivate when the ignition switch is removed from the RUN position or after any action that would activate or deactivate the courtesy lamps, such as the interior lamp switch or opening a door.