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

INADV/PWR/LED Fuse B+ Terminal 2 X3

1

1

--

--

Panel Dimmer Switch DIM Up Signal

2

2

2

--

Panel Dimmer Switch DIM Down Signal

2

2

2

--

Incandescent Backlight Dimming Control Terminal 3 X2

1

1

1

--

LED Backlight Dimming Control Terminal 18 X3

B2610 00

1

1

--

LED Backlight Dimming Control Terminal 25 X3

B2625 00

1

1

--

Automatic Transmission Shift Lever Ground

--

1

--

--

Cigar Lighter Console Ground

--

1

--

--

Cigar Lighter Front Ground

--

1

--

--

Dome/Reading Lamps Ground

--

1

--

--

Door Lock/Window Switch Ground

--

1

--

--

Headlamp and Panel Dimmer Switch Ground

--

2

--

--

Multifunction Switch - Center Console Ground

--

1

--

--

Steering Wheel Control Switch Ground

--

1

--

--

1. Interior Backlighting Malfunction

2. Dimmer Switch Malfunction

Circuit/System Description

The up/down dimmer controls located on the headlamp and panel dimmer switch is used to increase and decrease the brightness of the interior backlighting components. Each dimmer control 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) supplies each dimmer control switch with a signal circuit. When either the up or down dimmer control switch is placed in the desired position, the dimmed voltage setting is applied from the appropriate dimmer control switch through the dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies the dimmed voltage to the LED backlight dimming control circuit and the interior backlighting components dim to the requested level.

Conditions for Running the DTC

    • Battery voltage must be between 9-16 volts.
    • Park lamps ON.

Conditions for Setting the DTC

DTC B2610 00 will set when the BCM detects a short to ground in the LED backlight dimming control circuit.

Actions Taken When the DTC Sets

The BCM will not dim or illuminate any indicators supplied by the LED backlight dimming control circuit.

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 Testing

  1. With a scan tool clear the DTC.
  2. Ignition OFF, disconnect the harness connectors at the following components.
  3. • Door lock/window switch
    • Headlamp and panel dimmer switch
    • Steering wheel controls
    • Multifunction switch - center console
    • Automatic transmission shift lever
    • Dome/reading lamps - front
    • Dome/reading lamps - rear
  4. Operate the vehicle within the conditions for running the DTC and verify the DTC does not reset.
  5. If the DTC resets, test the control circuit terminal 18 X3 for a short to ground. If the circuits test normal, replace the BCM.
  6. Reconnect each component one at a time and verify the DTC does not reset as current.
  7. 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.

    •  Headlamp Switch Replacement
    •  Cigar Lighter Receptacle or 12-Volt Accessory Power Receptacle Replacement
    •  Power Mirror Switch Replacement
    •  Control Module References for BCM replacement, setup, and programming