| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. | 
Circuit  | Short to Ground  | Open/High Resistance  | Short to Voltage  | Signal Performance  | 
|---|---|---|---|---|
B+, BCM C2 Terminal 2  | B2652 00  | B2652 00  | --  | --  | 
Instrument Panel Lamp Supply Voltage  | B2652 00  | 2  | 1  | --  | 
  | ||||
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 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 illuminating the components listed below:
| • | Headlamp switch | 
| • | Instrument panel cluster (IPC) | 
| • | Driver and passenger window switches | 
| • | Driver and passenger door lock switches | 
| • | Outside rearview mirror switch | 
| • | The ignition is ON. | 
| • | The headlamps or park lamps ON. | 
The BCM detects a short to ground on the instrument panel lamps supply voltage circuit.
The BCM does not attempt to illuminate the instrument panel lamps.
| • | The condition responsible for setting the DTC no longer exists. | 
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. | 
Interior Lights Dimming Schematics
Lighting Systems Connector End Views
Ignition ON, park lamps ON, adjust the dimmer switch from dim to full bright. The I/P lamps should dim and then become full bright.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the supply voltage circuits listed below for a short to ground. | 
| • | Instrument panel lamp supply voltage circuit terminal 3 C2 | 
| • | Instrument panel lamp supply voltage circuit terminal 3 C6 | 
| • | Instrument panel supply voltage circuit -terminal 3 C2 | 
| • | Instrument panel supply voltage circuit -terminal 3 C6 | 
| ⇒ | If the DTC resets, test the instrument panel lamp supply voltage circuit for a short to ground. If the circuit test normal, replace the BCM. | 
| ⇒ | If the DTC resets as current, test or replace the component responsible for setting the DTC. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |