Interior Lamps Dimming

WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

The second group includes lamps which may be dimmed. This group may use a combination of vacuum fluorescent (VF) illumination and of incandescent lamps.

Adjustable pedal position switch
Door switches and window switches
Fog lamp switch
Heated seat switches
HVAC control head assembly
Hazard switch
Outside rearview mirror switch
Power sunroof switch assembly
Radio
Rear compartment lid release switch
Rear seat audio module
Steering wheel radio controls
The instrument panel cluster (IPC)
Traction control switch

When the ignition switch is turned to the ON position, the VF displays (radio) turn ON at maximum brightness. When the park lamps are ON and the ambient light sensor indicates low light conditions, all incandescent back lighting turns ON at the dimming level indicated by the instrument panel (I/P) dimmer switch. At the same time all VF displays dim to match the indicated dimming level. The body control module (BCM) is responsible for the dimming of the interior lights. The BCM receives a varying signal from the I/P dimmer switch. Based on the position of the I/P dimmer switch, the BCM then supplies the appropriate amount of voltage to the interior lamps. When the headlight switch is turned to the PARK or HEADLAMP position, all incandescent back lighting, with the exception of the I/P backlighting, turns ON at the dimming level indicated by the I/P dimmer switch. When the I/P dimmer switch is moved from MIN to MAX, all VF displays, as well as all incandescent back lighting, respond from minimum intensity to maximum brightness in response to the I/P dimmer switch position. The I/P backlight is not integrated in the headlamp switch. The automatic lamp control system must determine if it's dark enough to turn the I/P backlights on. Once the I/P backlighting is turned on, the brightness is controlled by the I/P dimmer switch. In rainy weather, etc., the customer may comment that they manually turned on the headlamps, however, the I/P lights did not come on. It is important to note that the I/P backlight will only turn on when indicated by the Automatic Lamp Control's light sensor. This condition is not related to the headlamp switch function, BCM or I/P function. This is considered a normal condition and no parts should be replaced.