GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the headlamp switch to the OFF position.
  2. Turn the ignition switch to the RUN position.
  3. Cover the DRL ambient light sensor with a dark cloth.
  4. Using a test light, backprobe between the DRL control module harness connector C1 terminal A and ground.

Does the test light illuminate?

--

Go to Step 5

Go to Step 2

2

Using a test light, backprobe between the headlamp switch harness connector terminal P and ground.

Does the test light illuminate?

--

Go to Step 8

Go to Step 3

3

Do the exterior lamps function normally with the headlamp switch?

--

Go to Step 4

Go to Exterior Lights System Check

4

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Has the repair been made?

--

Go to Exterior Lights System Check

--

5

Using a test light, backprobe between the DRL control module harness connector C1 terminal H and ground.

Does the test light illuminate?

--

Go to Step 6

Go to Step 7

6

Repair the poor connection or open in circuit 9 between the DRL control module harness connector C1 terminal H and ground.

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--

7

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

--

8

Repair the poor connection or open in circuit 1872.

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--