GM Service Manual Online
For 1990-2009 cars only

DTC Descriptor

DTC B2652 00: Passenger Compartment Dimming 3

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

I/P Lamps Supply Voltage

B2652 00

2

1

--

  1. Interior Backlighting Does Not Dim
  2. Interior Backlighting Inoperative

Circuit/System Description

Voltage for the interior backlighting components is supplied from the Panel Dimming Fuse in the rear electrical center to the body control module (BCM).

The BCM applies a voltage reference through the instrument panel (I/P) dimming voltage reference circuit to the interior lamp dimming switch, which is part of the headlamp switch. When the dimming switch is placed in the desired position, the dimmed voltage setting is applied from the interior lamp dimming switch through the I/P dimming return circuit to the BCM. The BCM then applies the dimmed voltage to the I/P lamps supply voltage circuit and they dim to the correct level.

The IP lamps are located in the following components:

    • Cigar Lighter
    • Door Lock Switches
    • Headlamp Switch
    • Hazard Switch
    • I/P Cluster
    • Lumbar Switches
    • Power Window Switch
    • Power Mirror Switches
    • Power Seats Switches
    • PRNDL
    • Sunroof Switch
    • Sunshade Switch
    • TCS Switch
    • Universal Garage Door Opener Switch

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The BCM receives a ground signal on the I/P lamps supply voltage circuit.

Action Taken When the DTC Sets

The I/P lamps are not illuminated

Conditions for Clearing the DTC

The BCM clears this code from current when the fault is removed from the system.

Reference Information

Schematic Reference

Interior Lights Dimming Schematics

Connector End View Reference

Lighting Systems Connector End Views

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

Ignition ON, cover the ambient light sensor, vary the interior lamp dimming switch from dim to full bright. The I/P lamps should dim and then become full bright.

Circuit/System Testing

  1. Clear the DTC. Headlamp switch OFF, disconnect all interior lamps dimming related components. Refer to the circuit/system verification for all components that contain the I/P lamps. Verify the DTC B2652 does not set
  2. If the DTC resets then test for a short to ground in the I/P lamps supply voltage circuit. If the circuit/connections test normal replace the BCM.
  3. Reconnect each component one at a time and test for the DTC B2652.
  4. If the DTC resets, then replace that component.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Ashtray Lamp Bulb Replacement
    •  Headlamp Switch Replacement
    •  Hazard Warning Switch Replacement
    •  Interior Lamp Switch Replacement
    •  Power Seat Switch Replacement
    •  Driver Seat Adjuster Memory Switch Replacement
    •  Headlamp Switch Replacement
    •  Heated and Cooled Seat Switch Replacement
    •  Front Seat Lumbar Control Switch Replacement
    •  Transmission Floor Shift Control Indicator Lamp Replacement
    •  Sunroof Switch Replacement
    •  Garage Door Opener Replacement
    •  Vanity Mirror Lamp Replacement
    •  Driver Information Display Switch Replacement
    •  Control Module References for BCM replacement, setup, and programming