GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Inspect fuses EF13, left-side headlamps, and EF10, right-side headlamps.

Is fuse EF13 or EF10 open?

--

Go to Step 2

Go to Step 3

2

  1. Inspect for a short circuit and repair it, if necessary.
  2. Replace the fuse.

Is the repair complete?

--

System OK

--

3

Inspect the voltage at fuses EF13 and EF10.

Does the voltage available at fuses EF13 and EF10 measure within the specified range?

11-14 V

Go to Step 4

Go to Step 9

4

  1. Disconnect both headlamp connectors.
  2. Turn the headlamps ON.
  3. Select the low beams.

Does the voltage at each headlamp connector terminal 5 measure within the specified range?

11-14 V

Go to Step 6

Go to Step 5

5

Repair the open circuit between fuse EF13 or EF10 and the low beam headlamps.

Is the repair complete?

--

System OK

--

6

  1. Disconnect the headlamp connectors.
  2. Connect an ohmmeter between ground and either headlamp connector terminal 6.

Is the resistance equal to the specified value?

0 ohms

Go to Step 8

Go to Step 7

7

Repair the ground circuit.

Is the repair complete?

--

System OK

--

8

Replace the faulty headlamps.

Is the repair complete?

--

System OK

--

9

Inspect the voltage between fuses EF13 and EF10 and the headlamp relay.

Does the voltage available at fuses EF13 and EF10 measure within the specified range?

11-14 V

System OK

Go to Step 10

10

Repair the open circuit between fuses EF13 and EF10 and the headlamp relay.

Is the repair complete?

--

System OK

--