Volt

DTC B2610

The instrument panel dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The instrument panel 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 instrument panel dimmer switch. When the instrument panel dimmer switch is placed in the desired position, the dimmed voltage setting is applied from the instrument panel dimmer switch through the instrument panel dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies a pulse width modulated (PWM) voltage through the light emitting diode (LED) dimming control circuits illuminating the interior backlighting to the requested level of brightness.

DTC B2610 01

The BCM detects a short to battery in the LED backlight dimming control circuit terminal 8 X2 or the LED backlight dimming control circuit terminal 9 X7.

DTC B2610 02

The BCM detects a short to ground in the LED backlight dimming control circuit terminal 8 X2 or the LED backlight dimming control circuit terminal 9 X7.

DTC B2610 04

The BCM detects an open/high resistance in the LED backlight dimming control circuit terminal 8 X2 or the LED backlight dimming control circuit terminal 9 X7.

The BCM will disable the LED backlight dimming control circuits.

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

Scan Tool Reference

Control Module References for scan tool information

Note: Each component supplied by the LED backlight dimming control circuits may need to be disconnected to isolate the short to ground. Use the schematics to identify the following:

1. Vehicle OFF, disconnect the harness connector at any component with inoperative backlighting.
2. Vehicle OFF, scan tool disconnected, all doors closed, all accessories OFF, and wait 2 minutes. Test for less than 10 Ω between the appropriate ground circuit terminal listed below and ground:

•	A20 Radio/HVAC Controls - terminal 17

•	S16 Driver Information Centre Switch - terminal 4

•	E37F Dome/Reading Lamps - Front - terminal 6

•	S25 Garage Door Opener switch - terminal 3

•	S48B Multifunction Switch - Overhead Console amber LED - terminal 6

•	S70R Steering Wheel Controls Switch - Right - terminal 5

•	S70L Steering Wheel Controls Switch - Left - terminal 7

•	S91 Hand Brake Control Switch - terminal 8

•	S48B Multifunction Switch - Overhead Console - terminal 2

•	S52 Outside Wing Mirror Switch - terminal 11

•	S113 Charge Port Door Open Request Switch - terminal 4

•	S117 Refuel Request Switch - terminal 4

•	S83 Vehicle On/Off Switch - terminal 4

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

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

•	A20 Radio/HVAC Controls - terminal 18

•	S16 Driver Information Centre Switch - terminal 3

•	E37F Dome/Reading Lamps - Front - terminal 3

•	S25 Garage Door Opener switch - terminal 2

•	S48B Multifunction Switch - Overhead Console amber LED - terminal 3

•	S70L Steering Wheel Controls Switch - Left - terminal 6

•	S70R Steering Wheel Controls Switch - Right - terminal 4

•	S91 Hand Brake Control Switch - terminal 6

•	S48B Multifunction Switch - Overhead Console - terminal 1

•	S52 Outside Wing Mirror Switch - terminal 1

•	S113 Charge Port Door Open Request Switch - terminal 5

•	S117 Refuel Request Switch - terminal 5

•	S83 Vehicle On/Off Switch - terminal 8

4. Vehicle in Service Mode, command the LED Backlight Dimming ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 Body Control Module.

5. If all circuits test normal, replace the component with inoperative backlighting.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.