GM Service Manual Online
For 1990-2009 cars only

Daytime Running Lamps (DRL) Inoperative Export

Step

Action

Yes

No

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

1

Did you review the Exterior Lighting System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

  1. Start the engine and allow it to idle.
  2. Place the headlamp switch in the OFF position.

Do the low beam headlamps and tail lamps illuminate?

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

Go to Step 3

3

IS the LOW OIL Pressure indicator ON?

Go to Engine Oil Pressure Indicator Always On in Instrument Panel, Gages and Console

Go to Step 4

4

Are both the low beam headlamps and rear tail lamps inoperative?

Go to Step 7

Go to Step 5

5

Are the low beam headlamps inoperative?

Go to Step 6

Go to Step 12

6

  1. Place the headlamp switch in the HEAD position.
  2. Place the headlamp dimmer switch in the low beam position.

Do the low beam headlamps illuminate?

Go to Step 9

Go to Headlamps Inoperative - Low Beams

7

  1. Place the ignition switch in the OFF position.
  2. Disconnect the Daytime Running Lamp (DRL) control module connector.
  3. Place the ignition switch in the ON position.
  4. Probe the ignition voltage circuit of the DRL control module connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 16

8

Probe the ground circuit of the Daytime Running Lamp (DRL) control module with a test lamp that is connected to battery voltage.

Does the test lamp illuminate?

Go to Step 18

Go to Step 19

9

  1. Place the headlamp switch in the OFF position.
  2. Place the ignition switch in the OFF position.
  3. Disconnect the Daytime Running Lamp (DRL) control module connector.
  4. Probe the exterior lamps OFF input circuit of the Daytime Running Lamp (DRL) control module with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 10

Go to Step 15

10

With a test lamp that is connected to ground, probe the battery positive voltage circuit of the Daytime Running Lamp (DRL) control module connector that is fed by the HEAD LAMP circuit breaker.

Does the test lamp illuminate?

Go to Step 11

Go to Step 20

11

Connect a fused jumper between battery positive voltage and the low beam supply voltage circuit of the Daytime Running Lamp (DRL) control module . Refer to Circuit Testing in Wiring Systems.

Do the low beam headlamps illuminate?

Go to Step 18

Go to Step 21

12

Place the headlamp switch in the PARK position.

Do the tail lamps illuminate?

Go to Step 13

Go to Headlamps Inoperative - Low Beams

13

  1. Place the ignition switch in the OFF position.
  2. Disconnect the Daytime Running Lamp (DRL) control module connector.
  3. Place the ignition switch in the ON position.
  4. Place the headlamp switch in the OFF position.
  5. With a test lamp that is connected to a good ground, probe the battery positive circuit of the Daytime Running Lamp (DRL) control module that is fed by the PARK LP fuse.

Does the test lamp illuminate?

Go to Step 14

Go to Step 22

14

Connect a fused jumper between battery positive voltage and the parklamps supply voltage circuit of the Daytime Running Lamp (DRL) control module . Refer to Circuit Testing in Wiring Systems.

Do the tail lamps illuminate?

Go to Step 18

Go to Step 23

15

Test for a open or high resistance in the exterior lamps OFF input circuit of the Daytime Running Lamp (DRL) control module . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 17

16

Test for a open or high resistance in the ignition voltage circuit of the Daytime Running Lamp (DRL) control module . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 24

17

Inspect for poor connections at the harness connector of the headlamp 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 27

Go to Step 26

18

Inspect for poor connections at the harness connector of the daytime running lamps control module. 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 27

Go to Step 25

19

Repair an open or high resistance in the ground circuit of the Daytime Running Lamp (DRL) control module . Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 27

--

20

Repair an open or high resistance in the battery positive voltage circuit of the Daytime Running Lamp (DRL) control module connector that is fed by the HEAD LAMP circuit breaker. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 27

--

21

Repair an open or high resistance in the headlamp low beam supply voltage circuit of the Daytime Running Lamp (DRL) control module connector. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 27

--

22

Repair an open or high resistance in the battery positive circuit of the Daytime Running Lamp (DRL) control module that is fed by the PARK LP fuse. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 27

--

23

Repair an open or high resistance in the parklamps supply voltage circuit of the Daytime Running Lamp (DRL) control module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 27

--

24

Repair a short to ground the ignition voltage circuit in the Daytime Running Lamp (DRL) control module . Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 27

--

25

Replace the Daytime Running Lamps (DRL) control module. Refer to Daytime Running Lights (DRL) Control Module Replacement .

Is the repair complete?

Go to Step 27

--

26

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Is the repair complete?

Go to Step 27

--

27

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Daytime Running Lamps (DRL) Inoperative Domestic

Step

Action

Yes

No

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

1

Did you review the Exterior Lighting System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

  1. Place the ignition switch in the OFF position.
  2. Engage the park brake.
  3. Place the headlamp switch in the OFF position.
  4. Turn ON the ignition, with the engine OFF.
  5. Place the turn signal switch in the RH ON position.
  6. Place the turn signal switch in the LH ON position.

Do the front turn signals operate properly?

Go to Step 3

Go to Turn Signal Lamps and/or Indicators Inoperative

3

  1. Release the park brake.
  2. Apply a bright incandescent light to the DRL ambient light sensor.
  3. Place the turn signal switch in the OFF position.

Do the front turn signals lamps illuminate?

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

Go to Step 4

4

Is the park brake indicator in the instrument panel cluster (IPC) ON?

Go to Brake Warning Indicator Always On in Hydraulic Brakes

Go to Step 5

5

Are both the headlamps and park lamps illuminated?

Go to Step 6

Go to Step 7

6

  1. Turn OFF the ignition.
  2. Disconnect the DRL ambient light sensor.
  3. Place a fused jumper across the DRL ambient light sensor connector. Refer to Circuit Testing in Wiring Systems.
  4. Turn ON the ignition, with the engine OFF.

Do the turn signal lamps illuminate?

Go to Step 19

Go to Step 12

7

  1. Turn OFF the ignition.
  2. Disconnect the daytime running lamp (DRL) module connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 3 voltage circuit of the DRL module connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 15

8

Probe the ignition 1 voltage circuit of the DRL module connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 9

Go to Step 16

9

Probe the ground circuit of the DRL module connector with a test lamp that is connected to battery voltage.

Does the test lamp illuminate?

Go to Step 10

Go to Step 18

10

Connect a fused jumper between the park brake switch signal of the DRL module connector and ground. Refer to Circuit Testing in Wiring Systems.

Does the park brake indicator in the instrument panel cluster (IPC) illuminate?

Go to Step 14

Go to Step 11

11

  1. Place the ignition switch in the OFF position.
  2. Engage the park brake.
  3. Turn ON the ignition, with the engine OFF.

Is the park brake indicator in the instrument panel cluster (IPC) ON?

Go to Step 17

Go to Brake Warning Indicator Inoperative in Hydraulic Brakes

12

Test the low reference circuit of the DRL ambient light sensor for the following:

    • An open or a high resistance
    • A short to ground
    • A short to battery voltage

Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 13

13

Test the signal circuit of the DRL ambient light sensor for the following:

    • An open or a high resistance
    • A short to ground
    • A short to battery voltage

Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 14

14

Inspect for poor connections at the daytime running lamps DRL module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 20

15

Repair the open or high resistance in the ignition 3 voltage circuit of the DRL module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

16

Repair the open or high resistance in the ignition 1 voltage circuit of the DRL module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

17

Repair the open or high resistance in the park brake signal circuit of the DRL module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

18

Repair the open or high resistance in the ground circuit of the DRL module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

19

Replace the DRL ambient light sensor. Refer to Daytime Running Lamp (DRL) Ambient Light Sensor Replacement .

Did you complete the replacement?

Go to Step 21

--

20

Replace the DRL module. Refer to Daytime Running Lights (DRL) Control Module Replacement .

Did you complete the replacement?

Go to Step 21

--

21

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2