• | 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 X2 Terminal 2 | B2652 00 | B2652 00 | -- | -- |
I/P Lamps Supply Voltage | B2652 00 | 2 | 1 | -- |
1. Interior Backlighting Does Not Dim 2. Interior Backlighting Inoperative |
The body control module (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, supplied by the SWITCH DM Fuse located in the rear fuse block, through the instrument panel lamp supply voltage circuits illuminating the components listed below.
• | Ashtray Lamp |
• | Headlamp Switch |
• | Hazard Switch |
• | I/P Cluster |
• | Power Window Switches-Rear Doors |
• | Sunroof Switch |
• | TCS Switch |
• | Reverse Lockout Solenoid |
• | Garage Door Opener Transmitter |
• | 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
Interior Lighting Systems Description and Operation
Control Module References for Scan Tool Information
Ignition ON, cover the ambient light sensor, vary the interior lamp dimming 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 X2 |
• | Instrument panel lamp supply voltage circuit terminal 3 X6 |
• | Instrument panel lamp supply voltage circuit terminal 3 X2 |
• | Instrument panel lamp supply voltage circuit terminal 3 X6 |
⇒ | 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, 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 |