The instrument panel (I/P) lamp dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The I/P dimmer switch provides a voltage signal that will increase as the brightness of the lights are increased and decrease as the brightness of the lights are decreased. The body control module (BCM) provides a low reference signal and a B+ voltage reference 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 the dimmed voltage to the I/P lamps supply voltage circuit and the interior backlighting components dim to the requested level. Ground for the I/P dimmer switch is provided at G200.

DTC B2652 00 will set for the following conditions:

The BCM will not DIM or illuminate any I/P lamps supplied by the I/P lamps dimmer switch signal circuit.

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

1. Ignition OFF, disconnect the X2 harness connector at the BCM.
2. Verify a test lamp illuminates between the BCM 7 fuse B+ circuit terminal 2 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Reconnect the X2 harness connector at the BCM.
4. Ignition ON, with a scan tool clear all DTCs.
5. Ignition OFF, disconnect the harness connectors at the following components:

•	Power window switch - left rear

•	Power window switch - right rear

•	PRNDL lamp

•	Sunroof control switch

•	Sunroof shade switch

6. Ignition ON, operate the vehicle within the conditions for running the DTC and verify the DTC does not reset.

⇒	If the DTC resets, test the appropriate signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the BCM.

•	Power window switch - left rear terminal A

•	Power window switch - right rear terminal A

•	PRNDL lamp terminal A

•	Sunroof control switch terminal A

•	Sunroof shade switch terminal A

7. Reconnect each component one at a time and verify the DTC does not reset as current.

⇒	If the DTC resets as current, test or replace the component responsible for setting the DTC.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.