GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Park Avenue 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Daytime Running Lamps (DRL) Always On

Step

Action

Yes

No

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

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Important:: Vehicle shift lever must be out of the PARK position and the parking brake disengaged in order for the daytime running lamps (DRL) to operate.

  1. Verify the headlamp switch is in the OFF position.
  2. Turn ON the ignition, with the engine OFF.
  3. Place the twilight switch to the MAX position.
  4. Depress and hold the brake pedal.
  5. Move the gear selector out of PARK position.
  6. Verify the parking brake is disengaged.
  7. Expose the ambient light sensor to a bright light.
  8. Wait about 20 seconds.
  9. Observe the DRL lamps.
  10. Cover the ambient light sensor.
  11. Wait about 20 seconds.
  12. Observe the DRL lamps.
  13. Place the gear selector in the PARK position.
  14. Release the brake pedal.

Did the DRL operate properly?

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

Go to Step 3

3

Do the low beam headlamps operate properly?

Go to Step 4

Go to Headlamp Low or High Beams Always On

4

Does the twilight sentinel operate properly?

Go to Step 5

Go to Twilight Sentinel Inoperative

5

Test for an open circuit in the PARK/NEUTRAL position switch park signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 6

6

Inspect for poor connections at the harness connector of the lighting control module (LCM). 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 8

Go to Step 7

7

Replace the LCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2