GM Service Manual Online
For 1990-2009 cars only

Headlamps On in Daylight Conditions Domestic

Step

Action

Value(s)

Yes

No

1

Was the entire DRL system check performed?

--

Go to Step 2

Go to Daytime Running Lights (DRL) System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Make sure the headlamps are off.
  3. Disconnect the headlamp switch.

Do the headlamps turn off?

--

Go to Step 3

Go to Step 4

3

Replace the headlamp switch. Refer to Headlamp Switch Replacement

Is the repair complete?

--

Go to Step 13

--

4

Disconnect the ambient light sensor.

Do the headlamps turn off?

--

Go to Step 5

Go to Step 6

5

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

Is the repair complete?

--

Go to Step 13

--

6

Disconnect the the DRL module.

Do the headlamps turn off?

--

Go to Step 7

Go to Step 8

7

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

Is the repair complete?

--

Go to Step 13

--

8

Disconnect the headlamp dimmer switch.

Do the headlamps turn off?

--

Go to Step 9

Go to Step 10

9

Check for a short to B+ in circuit 10.

Is a short to B+ present?

--

Go to Step 11

Go to Step 12

10

Repair a short to B+ in circuit 12.

Is the repair complete?

--

Go to Step 13

--

11

Repair a short to B+ in circuit 10.

Is the repair complete?

--

Go to Step 13

--

12

Replace the headlamp dimmer switch.

Is the repair complete?

--

Go to Step 13

--

13

  1. Turn the ignition switch to the OFF position.
  2. Reconnect all connectors/components removed.

Have all repairs been made?

--

Go to Daytime Running Lights (DRL) System Check

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