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 B2625 02: Display Dimming Pulse Width Modulation (PWM) Output Circuit Short to Ground

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Instrument Panel Lamps Dimmer Switch Signal | 1 | 1 | -- | --
Instrument Panel Lamps Control | B2625 02 | 1 | 1 | --
Park Lamp Control | 2 | 2 | 2 | --
Instrument Panel Lamps Dimmer Switch Low Reference | -- | 1 | 1 | --
1. Interior Backlighting Malfunction 2. Park, License, and/or Tail Lamps Malfunction

### Circuit/System Description

The body control module (BCM) receives an input from the instrument panel (I/P) dimmer switch. The BCM provides the I/P dimmer switch with voltage and a low reference. The I/P dimmer switch is a potentiometer that varies the input signal voltage to the BCM. This input determines the intensity level of the backlighting illumination. The driver may change intensity of the backlighting by positioning the I/P dimmer switch between the minimum and maximum settings. The BCM will default to full intensity if the input from the I/P dimmer switch is not within the specified values. The backlighting illumination intensity is controlled by the BCM by varying the pulse width modulation (PWM) voltage that feeds the dimming signal circuits of the individual lamps. All interior backlighting lamps are permanently grounded.

### Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

### Condition for Setting the DTC

DTC B2625 02 will set when the BCM detects a short to ground in the instrument panel lamps supply voltage circuit.

### Action Taken When the DTC Sets

When DTC B2625 02 is present, the interior backlighting will not operate.

### 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. Ignition OFF, disconnect the harness connectors at all components fed by the I/P lamps supply voltage circuit.
2. Verify DTC B2625 02 is not set.

⇒ | If the DTC sets as current, test the I/P lamps control circuit for a short to ground. If the circuit tests normal, replace the BCM.

3. Ignition OFF, connect each component fed by the I/P lamps control circuit one at a time and verify each time that the DTC does is set.

⇒ | If the sets, replace the component that caused the DTC to set.

4. If all circuits test normal, replace the BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Electronic Traction Control Switch Replacement

• | Front Side Door Window Switch Replacement

• | Radio Replacement

• | Instrument Cluster Replacement

• | Fog Lamp Switch Replacement

• | Hazard Warning Switch Replacement

• | Heater and Air Conditioning Control Replacement

• | Power Mirror Switch Replacement

• | Control Module References for BCM replacement, setup, and programming