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Daytime Running Lamps (DRL) Inoperative

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Daytime Running Lamps (DRL) Inoperative Diagnostic Test

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 Systems Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - Lighting Systems 
2 Verify that the daytime running lamps (DRL) are inoperative.
Do the DRL operate normally?		 Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems Go to Step 3 
3 Do the low beam headlamps operate normally? Go to Step 4  Go to Symptoms - Lighting Systems 
4
  1. Ensure that the park brake is not SET.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. With a 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 6  Go to Step 5 
5 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 a condition?		 Go to Step 12  Go to Step 8 
6
  1. Remove the headlamp driver module (HDM).
  2. Install a test lamp between the headlamp driver module connector battery positive voltage circuit terminal and the headlamp driver module control circuit terminal. Refer to Circuit Testing in Wiring Systems.
  3. Use the scan tool to command the DRL ON while observing the test lamp.
Does the test lamp illuminate at slightly less than full intensity?		 Go to Step 11  Go to Step 7 
7 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 12  Go to Step 9 
8 Inspect for poor connections at the harness connector of the park brake switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 12  Go to Step 10 
9
IMPORTANT: Perform the setup procedure for the BCM.
Replace the body control module (BCM). Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement?		 Go to Step 12  -
10 Replace the park brake switch. Refer to Park Brake Warning Lamp Switch Replacement in Park Brake.
Did you complete the replacement?		 Go to Step 12  -
11 Replace the headlamp driver module (HDM). 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 12  -
12
  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 
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