GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2007 🢒 Lucerne 🢒 DTC 🢒 DTC B2610

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

Backlight Lamp Control

B2610 00

2

1

--

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

Circuit/System Description

The 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 variable voltage through the backlight lamp control circuit illuminating the components listed below:

    • Clock
    • Diver information center (DIC) switch
    • Headlamp switch
    • HVAC control head
    • Rear HVAC control
    • Radio
    • Steering wheel control switch

Conditions for Running the DTC
    • The ignition is ON.
    • The headlamps or park lamps ON.

Conditions for Setting the DTC

The BCM detects a short to ground on the backlight lamp control circuit.

Action Taken When the DTC Sets

The BCM will not DIM or illuminate any backlighting supplied by the backlight lamp control circuits.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists.
    • A history DTC will clear once 100 consecutive malfunction ignition cycles have occurred.

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, adjust the interior lamp dimming switch from dim to full bright. The backlight lamps should dim and then become full bright.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connectors at all components fed by the backlight lamp control circuits listed below.
    2. • Backlight lamp control terminal 18 C3
    • Backlight lamp control terminal 21 C6
  2. Ignition ON, clear the DTC with a scan tool.
  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 circuits for a short to ground. If the circuits test normal, replace the BCM.
  4. Reconnect each component one at a time and verify that the DTC does not reset as current.
    5. ⇒If the DTC resets as current, test or replace the component responsible for setting the DTC.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Driver Information Display Switch Replacement
    •  Steering Wheel Control Switch Assembly Replacement
    •  Control Module References for BCM, HVAC control module, and radio replacement, setup, and programming