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Home >> Chevrolet >> 2007 >> Impala SS >> Repair and Diagnosis >> External Pages >> Different car >> Section 249 (Lighting Systems) >> Diagnostic Information and Procedures >> Interior Backlighting Malfunction >> Circuit/System Description
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Circuit/System Description

WARNING: This page is about a different car, the 2006 Chevrolet Monte Carlo and 2006 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

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 lamps dimmer switch signal circuit to the BCM. The BCM interprets this voltage signal, then applies a pulse width modulated (PWM) voltage through the instrument panel lamp supply voltage circuit, the backlight lamp control circuit, and the LED dimming supply circuit illuminating the LED and I/P panel lamps. For more detailed information concerning interior lamp operation refer to Interior Lighting Systems Description and Operation .