GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Is the DRL always in the daylight mode (the low beam headlights ON at a reduced intensity)?

--

Go to Step 2

Go to Step 7

2

Disconnect the DRL ambient light sensor.

Does the DRL change modes?

--

Go to Step 3

Go to Step 4

3

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

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--

4

Inspect for a short to ground in circuit 1137.

Is there a short to ground in circuit 1137.

--

Go to Step 5

Go to Step 6

5

Repair a short to ground in circuit 1137

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--

6

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

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--

7

  1. Disconnect the DRL ambient light sensor.
  2. Attach a 3A fused jumper between the ambient light sensor harness connector terminal A and terminal B.

Does the DRL change modes?

--

Go to Step 3

Go to Step 8

8

Inspect for a poor connection or an open in circuit 1138.

Is there a poor connection or an open in circuit 1138?

--

Go to Step 9

Go to Step 10

9

Repair a poor connection or open in circuit 1138.

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--

10

Inspect for a poor connection or open in circuit 1137.

Is there a poor connection or an open in circuit 1137?

--

Go to Step 11

Go to Step 6

11

Repair a poor connection or open in circuit 1137.

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--