B2652

DTC B2652

Diagnostic Instructions

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



DTC Descriptor
DTC B2652 00
- Passenger Compartment Dimming 3




Diagnostic Fault Information






Circuit/System Description

The instrument panel (I/P) lamp dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The I/P dimmer 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) provides a low reference signal and a B+ voltage reference to the I/P dimmer switch. When the I/P dimmer switch is placed in the desired position, the dimmed voltage setting is applied from the I/P dimmer switch through the I/P dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies the dimmed voltage to the I/P lamps supply voltage circuit and the interior backlighting components dim to the requested level. Ground for the I/P dimmer switch is provided at G201.


Conditions for Running the DTC

* Battery voltage must be between 9-16 volts.
* Park lamps ON.



Conditions for Setting the DTC

The BCM detects a short to ground in the I/P lamps dimmer switch signal circuit.


Actions Taken When the DTC Sets

The BCM will not DIM or illuminate any I/P lamps supplied by the I/P lamps dimmer switch signal 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.



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 Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Testing

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

* Headlamp Switch terminal 8
* Sunroof switch terminal 5
* Front door lock switch terminal B - w/o AN3
* Driver window switch terminal A X2 - w/o AN3
* Front passenger window switch terminal F - w/o AN3
* OSRVM switch terminal G - w/o AN3
* Transfer case shift control switch terminal 6
* Roof beacon switch terminal 1
* Sliding rear window switch terminal D
* Rear window switch terminal F


• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the listed backlighting control circuit terminal and ground.

* Headlamp Switch terminal 7
* Sunroof switch terminal 3
* Front door lock switch terminal A - w/o AN3
* Driver window switch terminal 1 X1 - w/o AN3
* Front passenger window switch terminal B - w/o AN3
* OSRVM switch terminal E - w/o AN3
* Transfer case shift control switch terminal 5
* Roof beacon switch terminal 2
* Sliding rear window switch terminal E
* Rear window switch terminal B

4. Command the Dimming Test high to low with a scan tool. The test lamp should turn from bright to dim when changing between the commanded states.

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

5. If all circuits test normal, test or replace the appropriate component.



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 (Programming and Relearning) for BCM replacement, setup, and programming