Circuit/System Description
WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
Battery voltage is supplied at all times to the body control module (BCM) from the SWITCH DM fuse located in the rear fuse block. The BCM supplies a voltage reference through the instrument panel (I/P) dimming voltage reference circuit to the interior lamp dimmer switch, which is part of the headlamp switch. When the dimmer switch is placed in a desired brightness position, reference voltage is applied through the dimmer switch rheostat and the I/P dimming switch signal circuit to the BCM. The BCM interprets this voltage signal, then applies a variable voltage through the backlight lamp control circuits illuminating the components listed below.
- Headlamp switch
- HVAC control head
- Diver information center (DIC) switch
- Clock
- Radio
- Rear HVAC control
- Steering wheel control switch