When the interior lamps circuits are closed/enabled, the
courtesy lamp relay is activated by the two following coil circuits:
| • | CKT 690 (GRY/BLK) which is the courtesy lamp enable output
of the body control module (BCM) driving the coil side of the relay. |
| • | CKT 1732 (ORN) which is the coil output side of the relay
going to the potential grounding switches/sources. |
When the courtesy lamp relay is enabled, CKT 156 (WHT) (courtesy
lamp output) is enabled by the closed contact at the relay and then grounded
by CKT 750 (BLK) at G110.
Some of these circuits can also be activated with the headlamp and panel
dimmer switch. When this happens, the coil output side of the inadvertent
power relay is grounded to the body control module (BCM) via CKT 1393
(DK BLU)
CKT 40 (ORN) from the courtesy fuse drives both input sides of
the inadvertent power relay. When the contact is pulled closed, CKT 1732
(ORN) is supplied power, thus driving any lamps/circuits attached that circuit
and providing ground.
The body control module (BCM) also monitors the following four door
inputs:
| • | CKT 49 (DK BLU) -- LH door jamb switch input |
| • | CKT 54 (ORN) -- RH door jamb switch input |
| • | CKT 775 (PNK) -- Side door jamb switch input |
| • | CKT 656 (YEL) -- Rear door jamb switch input/liftgate
strut switch input (depending on option content) |
When the doors are closed, the body control module (BCM) is in a floating
state of 0-2 volts. When the doors are opened, the courtesy lamp relay
is activated, sending power to the courtesy lamps.
The headlamp and panel dimmer switch also activates the following interior
courtesy lamps when the switch is placed in the PARK or HEADLAMP ON positions:
| • | RH power door lock switch |
| • | LH power door lock switch |
| • | LH outside rearview mirror control switch |
| • | Rear radio control head |
The dome lamps can be disabled by closing the dome lamp defeat switch
located on the headlamp and panel dimmer switch.
