GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition to the OFF position.
  2. Turn the headlamp switch to the OFF position.
  3. Disconnect the daytime running lamps (DRL) control module.
  4. Using a test light, in probe between the DRL control module harness connector C1 terminal H and ground.

Does the test light illuminate?

--

Go to Step 5

Go to Step 2

2

  1. Reconnect the DRL control module.
  2. Attach a 3A fused jumper between the DRL ambient light sensor harness connector terminal A and terminal B.
  3. Turn the ignition switch to the RUN position.

Do the park lamps turn ON?

--

Go to Step 3

Go to Step 4

3

  1. Inspect for a poor connection or open in circuit 1137.
  2. Inspect for a poor connection or an open in circuit 1138.
  3. If the circuit is OK, 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

--

4

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

--

5

  1. Disconnect the headlamp switch connector.
  2. Using a test light, probe between the headlamp switch connector terminal R and ground.

Does the test light illuminate?

--

Go to Step 6

Go to Step 7

6

Repair a short to B+ in circuit 9.

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--

7

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Has the repair been made?

--

Go to Daytime Running Lights (DRL) System Check

--