Diagnostic Instructions
| • | 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. |
DTC Descriptor
DTC B2625 00: Display Dimming Pulse Width Modulation (PWM) Output CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
LED Indicator Dimming Supply | B2625 00, 1, 2 | 2 | 1 | -- |
1. Interior Backlighting Does Not Dim 2. Interior Backlighting Inoperative | ||||
Circuit/System Description
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 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 LED dimming supply circuit illuminating the components listed below to the requested level.
| • | Clock |
| • | DIC switches |
| • | Headlamp switch |
| • | HVAC control module |
| • | Telltale assembly info center |
| • | Rear HVAC module |
| • | Left and right rear heated seat switch indicators |
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The BCM detects a short to ground on the LED dimming supply circuit.
Action Taken When the DTC Sets
The BCM will not attempt to illuminate the LED indicator lamps.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear once 100 consecutive malfunction ignition cycles have occurred. |
Reference Information
Schematic Reference
Interior Lights Dimming Schematics
Connector End View Reference
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
Ignition ON, cover the ambient light sensor, vary the interior lamp dimming switch from dim to full bright. The LED lamps should dim and then become full bright.
Circuit/System Testing
- Ignition OFF, disconnect the harness connectors at all components fed by the LED backlight dimming supply circuit terminals listed below.
- Ignition ON, clear the DTC with a scan tool.
- Operate the vehicle within the conditions for running the DTC and verify the DTC does not reset.
- Reconnect each component one at a time and verify that the DTC does not reset as current.
| • | Terminal 25 X3 |
| • | Terminal 25 X7 |
| ⇒ | If the DTC resets, test the LED dimming supply 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM and HVAC control module replacement, setup, and programming |
