Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference: Lighting Systems Connector End Views or Body Control System Connector End Views in Body Control System

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

Verify that the low or high beam headlamps are always on.

Do the low and high beam headlamps operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Does the wiper activated headlamp (WAH) function of the wiper system operate normally?

Go to Step 6

Go to Step 4

With the key in RUN and the wiper switch in the OFF position, use the scan tool to monitor the Front Wipers Active input parameter.

Does the scan tool parameter display Inactive?

Go to Step 13

Go to Step 5

Test the windshield wiper switch signal 1 circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 20

Can you illuminate both low and high beam headlamps at the same time when activating the headlamp dimmer switch?

Go to Step 15

Go to Step 7

1. Turn the ignition ON with the engine OFF.
2. With a scan tool, observe the Headlamp On Switch and Headlamp OFF Switch data parameters in the Body Control Module (BCM) data list while cycling the headlamp switch between positions.

Does the scan tool change from Inactive to Active?

Go to Step 10

Go to Step 8

1. Disconnect the headlamp and panel dimmer switch. Refer to Headlamp Switch Replacement .
2. Place a fused jumper between the headlamp switch headlamps on and off signal circuits and the low reference circuit terminals.

Does the scan tool change from Inactive to Active?

Go to Step 14

Go to Step 9

Test for an open, high resistance, or short to ground in one of the following headlamp and panel dimmer switch circuits. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct a condition?

Go to Step 21

Go to Step 13

Remove the headlamp relay. Refer to Relay Replacement in Wiring Systems.

Do the low or high beam headlamps remain always on?

Go to Step 16

Go to Step 11

Test for a ground signal at the headlamp relay control circuit connector terminal. Refer to Circuit Testing and Electrical Center Identification Views in Wiring Systems.

Is a ground control signal present?

Go to Step 12

Go to Step 18

Test for a short to ground in the headlamp relay control circuit. Refer to Circuit Testing and Electrical Center Identification Views in Wiring Systems.

Did you find and correct a condition?

Go to Step 21

Go to Step 13

Inspect for poor connections at the harness connector of the Body Control Module (BCM). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 17

Inspect for poor connections at the harness connector of the headlamp and panel dimmer switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 19

Repair the short to ground in the right or left low or high beam headlamp ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

Repair the short to voltage in the right or left low beam headlamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

Important: Perform the setup procedure for the BCM.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 21

--

Replace the headlamp relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

Replace the headlamp and panel dimmer switch. Refer to Headlamp Switch Replacement .

Did you complete the repair?

Go to Step 21

--

Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.

Did you complete the repair?

Go to Step 21

--

1. Use the scan tool in order to clear any induced DTCs.
2. Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3