GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Jimmy - 2WD 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Daytime Running Lights (DRL) System Check

Daytime Running Lights (DRL) System Check Standard

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Turn the ignition switch to the OFF position.

    2. Do not set the park brake.

  2. For autmoatic transmission, place the transmission in PARK.

    3. For manual transmission, place the transmission in NEUTRAL. Block the wheels.

  3. Place the headlamp switch in the AUTO position.
  4. Ensure that a sufficient amount of light reaches the ambient light sensor. Use a trouble light if necessary.
  5. Turn the ignition switch to the ON position. Do not start the engine.
    • The DRLs are ON.
    • All of the other exterior lamps are OFF.
    • Headlamps On in Daylight Conditions

2
  1. Turn the ignition switch to the OFF position.
  2. Set the park brake.
  3. For automatic transmission, place the transmission in PARK.

    4. For manual transmission, place the transmission in NEUTRAL. Block the wheels.

  4. Place headlamp switch in the AUTO position.
  5. Turn the ignition switch to the ON position. Do not start the engine.
    • The DRLs are OFF.
    • All of the other exterior lamps are OFF.

Headlamps, DRL On With Park Brake Applied

3
  1. Cover the ambient light sensor in order to prevent any light from reaching the sensor.
  2. For automatic transmission, place the transmission in DRIVE, then in PARK.

    3. For manual transmission, place the transmission in NEUTRAL. Block the wheels. Do not set the park brake.

  3. Place headlamp switch in the AUTO position.
  4. Turn the ignition switch to the ON position. Do not start the engine.
    • The DRLs are OFF.
    • The headlamps are ON.
    • All of the other exterior lamps are ON.

4

Place the headlamp switch in the HEAD position.
    • The DRLs are OFF.
    • The headlamps are ON.
    • All of the other exterior lamps are ON.

*Refer to the appropriate symptom diagnostic table for the applicable abnormal result.

Daytime Running Lights (DRL) System Check Envoy

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Turn the ignition switch to the OFF position.

    2. Do not set the park brake.

  2. Ensure that a sufficient amount of light reaches the ambient light sensor.

    3. If necessary, place a trouble light above the ambient light sensor.

The DRLs turn ON.

2

Place the headlamp switch in the HEAD position.
    • The HID headlamps turn ON immediately with a bright flash and remain ON.
    • The DRLs turn OFF.

3
  1. Place headlamp switch in the AUTO position.
  2. Remove the trouble light. Cover the ambient light sensor in order to prevent any light from reaching the sensor.
  3. Turn the ignition switch to the ON position.
    • The HID headlamps turn ON with a bright flash within 1 minute and remain ON.
    • The DRLs turn OFF.

Headlamps Inoperative - Headlamp Switch in AUTO Position

4

Using the multifunction switch lever, select HIGH BEAMS.
    • The high beams turn ON.
    • The HID headlamps remain ON.

5
  1. Place a trouble light above the ambient light sensor.
  2. Turn ON the HID headlamps for at least 3 minutes.
  3. Turn the HID headlamps OFF, then immediately ON. This action is referred to as a hot re-strike.

The HID headlamps turn ON immediately with a bright flash and remain ON.

Headlamps Flash Momentarily, Then Turn Off

6
  1. Place the headlamp switch in the HEAD position.
  2. Observe the color of each HID headlamp.

Both headlamps are the same bluish color.

Headlamps are Different Colors

*Refer to the appropriate symptom diagnostic table for the applicable abnormal result.