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B2625




DTC B2625

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B2625 01
- Display Dimming Pulse Width Modulation Output Circuit Short to Battery

DTC B2625 02
- Display Dimming Pulse Width Modulation Output Circuit Short to Ground

DTC B2625 04
- Display Dimming Pulse Width Modulation Output Circuit Open

Diagnostic Fault Information






Circuit/System Description

The instrument panel (I/P) dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The I/P dimmer switch provides a voltage signal to the body control module (BCM) that will increase as the brightness of the lights are increased and decrease as the brightness of the lights are decreased. The BCM provides a low reference, signal, and B+ voltage reference circuits to the I/P dimmer switch. When the I/P dimmer switch is placed in the desired position, the dimmed voltage setting is applied from the I/P dimmer switch through the I/P dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies a pulse width modulated (PWM) voltage through the LED backlight dimming control circuit illuminating the LED backlighting to the requested level of brightness.

Conditions for Running the DTC

* Battery voltage must be between 9-16 V.

* Park lamps ON.

Conditions for Setting the DTC

The BCM detects a short to ground in the LED backlight dimming control circuit terminal 5 X1.

Actions Taken When the DTC Sets

The LED backlight dimming control circuit driver is shut down.

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 Interior Lights Dimming Schematics

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

Interior Lighting Systems Description and Operation Interior Lighting Systems

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors at the components listed below.

* S48C multifunction switch 1 - instrument panel

* S48D multifunction switch 2 - instrument panel

* S32LR seat heating switch - left rear

* S32RR seat heating switch - right rear

2. Connect a test lamp between the appropriate control circuit terminal listed below and ground.

* S48C multifunction switch 1 - instrument panel terminal 3

* S48D multifunction switch 2 - instrument panel terminal 3

* S32LR seat heating switch - left rear terminal 6

* S32RR seat heating switch - right rear terminal 6

3. Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool.

If the test lamp is always OFF

1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module.

2. Test for infinite resistance between the control circuit and ground.

If less than infinite resistance, repair the short to ground on the circuit.

If infinite resistance

3. Test for less than 2 ohms in the control circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, replace the K9 body control module.

If the test lamp is always ON

1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON.

2. Test for less than 1 V between the control circuit terminal and ground.

If 1 V or greater, repair the short to voltage on the circuit.

If less than 1 V, replace the K9 body control module.

If the test lamp turns ON and OFF

4. Test or replace the appropriate component with the inoperative backlighting.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Rear Seat Heater Switch Replacement Rear Seat Heater Switch Replacement

* Control Module References Control Module References for BCM replacement, programming, and setup