B2652

DTC B2652

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC B2652 00
- Passenger Compartment Dimming 3 Circuit

Diagnostic Fault Information






Circuit/System Description

The body control module (BCM) applies a 12 V reference voltage through the headlamp and panel dimmer switch 12 V reference circuit to the headlamp and panel dimmer switch. When the dimming switch is placed in the desired position, the dimmed voltage setting is applied from the headlamp and panel dimmer switch through the instrument panel (I/P) lamp dimming switch signal circuit to the BCM. The BCM then applies the dimmed voltage to the I/P lamp dimming control circuit and the components on the circuit.

Conditions for Running the DTC

* Battery voltage must be between 9-16 V.
* The ignition must be ON.

Conditions for Setting the DTC

The BCM receives an open, voltage, or ground signal on the I/P lamp dimming control circuit.

Action Taken When the DTC Sets

The I/P lamps are not illuminated.

Conditions for Clearing the DTC

* The conditions for setting the DTC are no longer present.
* A history DTC clears after 100 malfunction-free ignition cycles.
* The BCM receives the clear code command from the scan tool.

Reference Information
Schematic Reference

Interior Lights Dimming Schematics Interior Lights Dimming Schematics
Connector End View Reference

Component Connector End Views Connector Views
Description and Operation

Interior Lighting Systems Description and Operation Interior Lighting Systems
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

Note: Each back lighted component may need to be disconnected to isolate a short to voltage or short to ground. Use the schematic to identify the following:

* Back lighted components the vehicle is equipped with.
* Component locations on the back lighting dimming control circuit
* Each component's control and ground circuit terminals

1. Ignition OFF, disconnect the harness connector at any component with inoperative backlighting.
2. Ignition OFF, scan tool disconnected, interior lamps OFF, doors CLOSED, test for less than 5 ohm between the ground circuit and ground.

• If greater than the specified value, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the control circuit and ground.
4. Command the Incandescent Dimming Control ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, replace the component with the inoperative backlighting.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Refer to the appropriate replacement procedure for the component causing the condition.
* Control Module References Control Module References for BCM replacement, setup, and programming