For 1990-2009 cars

### 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 B2652 00 : Passenger Compartment Dimming 3 Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
INT LAMPS Fuse B+ | B2652 00 | B2652 00 | -- | --

### Circuit/System Description

The up/down dimmer controls located on the headlamp and panel dimmer switch is used to increase and decrease the brightness of the interior backlighting components. Each dimmer control switch provides a voltage signal that will increase as the brightness of the lights are increased and decrease as the brightness of the lights are decreased. The body control module (BCM) supplies each dimmer control switch with a signal circuit. When either the up or down dimmer control switch is placed in the desired position, the dimmed voltage setting is applied from the appropriate dimmer control switch through the dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies the dimmed voltage to the LED backlight dimming control circuit and the interior backlighting components dim to the requested level.

### Conditions for Running the DTC

• | Battery voltage must be between 9-16 volts.

• | Park lamps ON.

### Conditions for Setting the DTC

The DTC will set when the BCM detects a short to ground or an open/high resistance in the INT LAMPS fuse B+ circuit.

### Conditions for Clearing the DTC

• | The condition responsible for setting the DTC no longer exists.

• | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

• | DTC will not clear with a scan tool until the vehicles systems shut down for 10 minutes.

### Reference Information

#### Schematic Reference

Interior Lights Dimming Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Interior Lighting Systems Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. If all circuits test normal, replace the BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming