1. Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
2. Review Strategy Based Diagnosis for an overview of the diagnostic approach.
3. Diagnostic Procedure Instructions provides an overview of each diagnostic category.

The headlamp switch is supplied with ground at all times. When the headlamp switch is placed in either the park or low beam position, ground is applied to the license plate lamp signal circuit to the body control module (BCM). The BCM responds by applying battery voltage to the license plate lamp control circuit. This energizes the left and right license lamp.

B3883 01

B3883 02 or B3883 04

Headlamp switch in park or low beam position

B3883 01

The BCM detects a short to voltage on the control circuit.

B3883 02

The BCM detects a short to ground on the control circuit.

B3883 04

The BCM detects an open control circuit.

The condition for setting the DTC is no longer present.

Schematic Reference

Exterior Lights Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exterior Lighting Systems Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, perform the License Plate Lamps Command test. The license plate lamps should be ON / OFF.

1. Ignition OFF, disconnect the appropriate harness connector at the license plate lamps listed below:

•	E7L License Lamp - Left

•	E7R License Lamp - Right

2. Test for less than 5 Ω between the appropriate license plate lamp ground circuit harness connector terminal 2 and ground.

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

3. Connect a test lamp between the appropriate control circuit harness connector terminal 1 and ground.
4. Command the License Plate Lamp test with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	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 (BCM).

⇒	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 (BCM).

5. If all circuits test normal, test or replace the appropriate license plate lamp.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.