Daytime Running Lamps (DRL) Inoperative (Domestic)

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Step	Action	Yes	No
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
1	Did you perform the Lighting Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Lighting Systems
2	Block the drive wheels. Turn the ignition ON, with the engine OFF. Place the gear selector in the DRIVE position. Ensure the headlamp switch is in the AUTO position. Ensure the ambient light sensor is not covered or has no obstruction to daylight. Does the system operate normally?	Go to Testing for Electrical Intermittents in Wiring Systems	Go to Step 3
3	Is only one daytime running lamp (DRL) inoperative?	Go to Step 4	Go to Step 5
4	Test the supply and ground circuits of the affected lamp for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 16	Go to Step 15
5	Ensure the park brake is not set. Install a scan tool. Turn ON the ignition, with the engine OFF. With the scan tool, observe the park brake switch parameter in the Body Control Module (BCM) data list. Does the scan tool display RELEASED?	Go to Step 7	Go to Step 6
6	Test the signal circuit of the park brake switch 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 16	Go to Step 10
7	Turn OFF the ignition. Remove the DRL relay. Connect a 3-amp fused jumper wire between battery positive voltage and the DRL supply voltage circuit of the DRL relay. Do the DRL illuminate?	Go to Step 8	Go to Step 11
8	Test the DRL relay control circuit of the DRL relay for a ground signal. Refer to Circuit Testing in Wiring Systems Is a ground signal present?	Go to Step 14	Go to Step 9
9	Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 16	Go to Step 12
10	Inspect for poor connections at the harness connector of the park brake switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 16	Go to Step 13
11	Repair the DRL supply voltage circuit. Refer to Wiring Repairs in Wiring Systems Did you complete the repair?	Go to Step 16	-
12	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 16	-
13	Replace the park brake switch. Refer to Park Brake Warning Lamp Switch Replacement in Park Brake. Did you complete the replacement?	Go to Step 16	-
14	Replace the DRL relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement?	Go to Step 16	-
15	Replace the inoperative DRL. Did you complete the replacement?	Go to Step 16	-
16	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 3