Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Voltage for the interior backlighting components is supplied from the Panel Dimming Fuse in the rear electrical center to the body control module (BCM).

The BCM applies a voltage reference through the instrument panel (I/P) dimming voltage reference circuit to the interior lamp dimming switch, which is part of the headlamp switch. When the dimming switch is placed in the desired position, the dimmed voltage setting is applied from the interior lamp dimming switch through the I/P dimming return circuit to the BCM. The BCM then applies the dimmed voltage to the I/P lamps supply voltage circuit and they dim to the correct level.

The I/P lamps are located in the following components:

The ignition is ON.

The BCM receives a ground signal on the I/P lamps supply voltage circuit.

The I/P lamps are not illuminated.

The BCM clears this code from current when the fault is removed from the system.

Schematic Reference

Interior Lights Dimming Schematics

Connector End View Reference

Lighting Systems Connector End Views

Electrical Information Reference

Scan Tool Reference

Ignition ON, cover the ambient light sensor, vary the interior lamp dimming switch from dim to full bright. The I/P lamps should dim and then become full bright.

1. Clear the DTC. Headlamp switch OFF, disconnect all interior lamps dimming related components. Refer to the circuit/system verification for all components that contain the I/P lamps. Verify DTC B2652 does not set.

⇒	If the DTC resets, then test for a short to ground in the I/P lamps supply voltage circuit. If the circuit/connections test normal, replace the BCM.

2. Reconnect each component one at a time and test for the DTC B2652.

⇒	If the DTC resets, then replace that component.

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.