For 1990-2009 cars

### 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 Backlight Lamp Control | B2610 00 | 2 | 1 | --
1. Interior LED Backlighting Does Not Dim 2. Interior LED Backlighting Inoperative

### 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 variable voltage through the LED backlight lamp control circuit illuminating the components listed below, if equipped:

• | Clock

• | Console flood lamp

• | Diver information center (DIC) switch

• | Driver window switch

• | Headlamp switch

• | Head up display (HUD) Switch

• | Heated seat switches

• | HVAC control head

• | I/P switch assembly

• | Radio

• | Rear seat audio (RSA) control

• | Rear video/HVAC control

• | 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 LED backlight lamp control circuit.

### Action Taken When the DTC Sets

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

### Conditions for Clearing the DTC

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

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, command LED Dimming ON with a scan tool. The LED Dimming Relay Command parameter should display On and the LED Dimming should illuminate.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors at all components fed by the LED backlight lamp control circuits listed below.

• | LED backlight lamp control terminal 18 X3

• | LED backlight lamp control terminal 21 X6

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.

⇒ | 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.

⇒ | 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.

• | Clock Replacement

• | Driver Information Display Switch Replacement

• | Head Up Display Switch Replacement

• | Radio Control Switch Replacement - Rear

• | Driver or Passenger Seat Heater Switch Replacement

• | Steering Wheel Replacement

• | Control Module References for BCM, HVAC control module, and radio replacement, setup, and programming