• | 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 | B2545 00, B2652 00 | B2652 00 | -- | -- |
B+, BCM C4 terminal 4 | B2545 00, B2652 00 | B2545 00 | -- | -- |
Instrument Panel Lamp Supply Voltage | B2652 00 | 2 | 1 | -- |
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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. |
• | Terminal 3 C2 |
- | Headlamp Switch |
- | Instrument Panel Cluster (IPC) |
• | Terminal 3 C6 |
- | Driver Window Switch |
- | Driver Door Lock Switch |
- | Outside Rearview Mirror Switch |
- | Passenger Window Switch |
- | Passenger Door Lock Switch |
⇒ | If the DTC resets, test the supply voltage circuits for a short to ground. If the circuits 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 |