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
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 G200.
Conditions for Running the DTC
* Battery voltage must be between 9-16 volts.
* The Park Lamps are ON.
Conditions for Setting the DTC
* The BCM detects a short to ground in the I/P lamps dimmer switch signal circuit.
* The BCM detects a short to ground or an open/high resistance in the DIM fuse B+ circuit.
Action 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 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 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 inoperative 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 C
* Midgate Window switch terminal D
* Transfer Case Shift Control Switch terminal 6
* Automatic Transmission Shift Lever Position terminal B
* Global Window Switch terminal D
* Rear Window Switch terminal E
• 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 A
* Midgate Window switch terminal E
* Transfer Case Shift Control Switch terminal 5
* Automatic Transmission Shift Lever Position terminal A
* Global Window Switch terminal E
* Rear Window Switch terminal A
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 inoperative 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