GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

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

DTC Descriptor

DTC B2610 00: Passenger Compartment Dimming 1 Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

LED Dimming Control

B2610 00

1

1

--

1. Interior Backlighting Malfunction

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 brightness 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 LED dimming control circuit illuminating the components listed below:

    • Radio
    • Inflatable Restraint I/P Module Disable Switch
    • Driver Information Center (DIC) Switch
    • Steering Wheel Control Switches

Conditions for Running the DTC

    • Ignition ON.
    • The headlamps or park lamps are ON.

Conditions for Setting the DTC

The BCM detects a short to ground on the LED dimming control circuit.

Action Taken When the DTC Sets

The BCM does not attempt to illuminate the LED 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

Connector End View Reference

Component Connector End Views

Description and Operation

Interior Lighting Systems Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

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

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connectors at all components fed by the BCM LED backlight lamp control circuit terminal 18 X3.
  2. Ignition ON, with a scan tool, clear the DTC.
  3. Operate the vehicle within the conditions for running the DTC and verify the DTC does not reset.
  4. If the DTC resets, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
  5. Reconnect each component one at a time and verify the DTC does not reset as current.
  6. If the DTC resets as current, replace the component responsible for setting the DTC.
  7. If all circuits test normal, replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Steering Wheel Control Switch Assembly Replacement
    •  Instrument Panel Inflatable Restraint Module Switch Replacement
    •  Control Module References for BCM or radio replacement, setup, and programming