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 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 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 instrument panel lamp supply voltage circuit illuminating the components listed below:
* Headlamp Dimmer Switch
* Tow/Haul Switch
* Traction Control Switch
* HVAC Control Module
* Driver Window Switch
* Driver Door Lock Switch
* Auxiliary Blower Motor Switch
* Passenger Window Switch
* Passenger Door Lock Switch
* Auxiliary Front HVAC Control Assembly
* Auxiliary Rear HVAC Control Assembly
Conditions for Running the DTC
* Ignition ON.
* The headlamps or park lamps ON.
Conditions for Setting the DTC
The BCM detects a short to ground on the instrument panel lamps supply voltage circuit.
Action Taken When the DTC Sets
The BCM does not attempt to illuminate the instrument panel 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-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 Verification
Ignition ON, park lamps ON, adjust the dimmer switch from dim to full bright. The I/P lamps should dim and then become full bright.
Circuit/System Testing
1. Ignition OFF, disconnect the X2 harness connector at the BCM.
2. 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. Ignition OFF, connect the X2 harness connector at the BCM.
4. Disconnect the harness connectors at all components fed by the BCM control circuit terminal 3 X2.
5. Ignition ON, clear the DTC with a scan tool.
6. Operate the system within the Conditions for Running the DTC and verify the DTC does not reset.
• If the DTC resets, test the control circuits for a short to ground. If the circuits test normal, replace the BCM.
7. Reconnect each component one at a time and verify that the DTC does not reset.
• If the DTC resets, test or replace the component responsible for setting the DTC.
8. If all circuits test normal, replace the BCM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Headlamp Switch Replacement (Service and Repair)
* Auxiliary Blower Motor Switch Replacement (Service and Repair)
* Auxiliary Heater and Air Conditioning Control Replacement - Front (Auxiliary Heater and Air Conditioning Control Replacement - Front)
* Auxiliary Heater and Air Conditioning Control Replacement - Rear (Auxiliary Heater and Air Conditioning Control Replacement - Rear)
* Front Side Door Window Switch Replacement (Service and Repair)
* Door Lock Switch Replacement (Service and Repair)
* Heater and Air Conditioning Control Replacement (Heater and Air Conditioning Control Replacement)
* Tow/Haul Switch Replacement (4L60-E/4L65-E/4L70-E - Automatic Transmission)
* Instrument Panel Inflatable Restraint Module Switch Replacement (Service and Repair)
* Electronic Traction Control Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming