Interior Lamps Dimming
This group of interior lighting includes lamps which may be dimmed. This group
uses a combination of class 2 controlled illumination and incandescent lamps:
| • | Driver information center (DIC) switch |
| • | Head up display (HUD) switch |
| • | HVAC control assembly |
| • | Instrument panel cluster (IPC) |
| • | Steering wheel controls |
| • | Traction control switch |
For the interior lighting to be dimmed the following conditions must be met:
| • | A low light level has been detected by the dash integration module (DIM) |
| • | Headlamp switch is placed in to the PARK or HEAD position |
| • | Ignition switch is placed in the ON position |
Then all class 2 displays and all incandescent back lighting will
be illuminated to the level set by the instrument panel (I/P) dimmer switch. When
the I/P dimmer switch is moved from MIN to MAX, all class 2 displays
and all incandescent back lighting respond from minimum intensity to maximum
brightness.
The DIM supplies battery positive voltage to the coil side of the PRK LP relay
in the rear fuse block.
When the I/P dimmer switch is moved from MIN to MAX, then the instrument panel
module (IPM), W/CJ2, or climate control panel (CCP), W/C67, applies a message to the
class 2 communication circuit to the DIM. The DIM then applies a ground to
the park lamp relay control circuit. This energizes the PRK LAMP relay and allows
battery positive voltage to be applied through the DIMR fuse to the DIM. The DIM then
illuminates the following incandescent lamps through the incandescent dimming output
circuit:
| • | HVAC control assembly |
| • | Steering wheel controls |
The DIM also applies a message to the following class 2 controlled illumination
components:
| • | Drivers door module (DDM) |
| • | HVAC control assembly |
The DDM will then send a message through the simple bus interface (SBI) to the
RH front door module (RFDM). The door modules will then illuminate the following components
through the incandescent dimming output circuit:
| • | Heated seat switch (W/KA1) |
| • | Memory function switch (W/A45) |
| • | Passenger heater A/C control (W/CJ2) |
| • | Power door lock switch |
The ground for these components are provided from the DDM and RFDM.
The following components are grounded at G200:
| • | HVAC control assembly |
| • | Steering wheel controls |
The following components are grounded at G201:
Battery Rundown Protection
Battery positive voltage is applied at all times to the INT LP fuse and to the
coil side of the INT LAMP relay in the rear fuse block. The rear integration module
(RIM) supplies a ground through the INT lamp control circuit to the INT LAMP relay
coil. This energizes the INT LAMP relay and applies battery positive voltage to all
the interior lamps. This relay provides a parasitic load protection and the RIM will
keep this relay active for 10 minutes following the ignition being turned to
the OFF position and retained accessory power (RAP) being deactivated or timed out.
The 10 minutes is reduced to 3 minutes if mileage of the vehicle is
less then 22.5 km (14 mi).
