For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle

• | Review Strategy Based Diagnosis

• | Diagnostic Procedure Instructions

### DTC Descriptor

DTC B2610 02: Passenger Compartment Dimming 1 Circuit Short to Ground

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
LED Interior Backlighting Control (X2) Terminal 8 | B2610 02 | 2 | 1 | --
LED Interior Backlighting Control (X7) Terminal 9 | B2610 02 | 2 | 1 | --
Backlighting Ground | -- | 2 | -- | --

1. Interior Backlighting at Full Intensity and Cannot be Dimmed
2. Interior Backlighting do not Illuminate

### Circuit/System Description

The body control module (BCM) supplies a voltage reference through the instrument panel cluster dimming voltage reference circuit to the instrument panel cluster lamps 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 instrument panel cluster lamps dimmer switch signal circuit to the BCM. The BCM interprets this voltage signal, then applies a pulse width modulated (PWM) voltage through the instrument panel lamp control circuit, the backlight lamp control circuit, and the LED dimming control circuit illuminating the LEDs and instrument panel cluster lamps and the components listed below, if equipped:

• | Heated seat control module - driver

• | Dome/reading lamps

• | Dome/reading lamps - row

• | Sunroof switch

• | Sunroof sunshade switch

• | Rear window sunshade switch

• | Sunroof ventilation switch

• | Intrusion sensor defeat switch

• | Outside rearview mirror switch

• | Window switch - driver

• | Rear compartment lid release switch - interior

• | Window switch - passenger

• | Window switch - left rear

• | Window switch - right rear

• | Steering wheel control switch

• | Headlamp switch

• | Park brake control switch

• | Ignition mode switch

• | Automatic transmission shift lever

• | Hazard warning switch

• | Multifunction switch - I/P 1

• | Multifunction switch - I/P 2

### 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

• | 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

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

### Circuit/System Verification

Ignition ON, command the LED Interior Ambient Lighting 1 Duty Cycle test with a scan tool. The commanded brightness by the scan tool should correspond the brightness of the illumination.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors at the appropriate inoperative backlighting component.
2. Test for less than 5 Ω between the black wire of the appropriate component and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect a test LED between the control circuit of the appropriate component and ground.
4. Command with the scan tool the Interior Ambient Lighting 1 Command to full intensity and back again.

⇒ | If the LED cannot be dimmed test the control circuit for a short to voltage or replace the K9 Body Control Module (BCM).

⇒ | If the LED do not emit at all test the control circuit for open/high resistance or replace the K9 Body Control Module (BCM).

5. If all circuit test normal, test or replace the appropriate inoperative backlighting component.

### Repair Instructions

Perform the Diagnostic Repair Verification

• | Dome Lamp Replacement

• | Sunroof Switch Replacement

• | Outside Remote Control Rearview Mirror Switch Replacement

• | Front Side Door Window Switch Replacement

• | Rear Side Door Window Switch Replacement

• | Rear Compartment Lid Release Switch Replacement

• | Steering Wheel Inflatable Restraint Module Replacement

• | Headlamp Switch Replacement

• | Parking Brake Indicator Switch Replacement

• | Steering Column Lock and Ignition Switch Cylinder Replacement

• | Hazard Warning Switch Replacement

• | Instrument Panel Multifunction Switch Replacement

• | Body Control Module Replacement

• | Control Module References