GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference: Component Connector End Views

1

Inspect the high-beam headlamps in the flash-to-pass mode.

Do the high-beam headlamps work in the flash-to-pass mode?

--

Go to Step 10

Go to Step 2

2

Measure the voltage at the headlamp switch connector terminal 7.

Does the voltage measure within the specified range?

11-14 V

Go to Step 4

Go to Step 3

3

Repair the open circuit between the headlamp switch connector terminal 7 and the fuse Ef12.

Did you complete the repair?

--

System OK

Go to Step 4

4

Inspect fuses Ef15.

Is the fuse open?

--

Go to Step 5

Go to Step 6

5

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

Did you find and correct the condition?

--

System OK

--

6

  1. Turn the high-beam headlamps ON.
  2. Measure the voltage at fuses Ef15.

Does the voltage available at fuses Ef15 measure within the specified range?

11-14 V

Go to Step 7

Go to Step 12

7

  1. Turn the high-beam headlamps ON.
  2. Measure the voltage at headlamp terminal 4 (terminal 2 if hatchback) with high beams selected.

Does the voltage available at the headlamp connector terminal 4 measure within the specified range?

11-14 V

Go to Step 9

Go to Step 8

8

Repair the open circuit between fuse EF16 and the high-beam headlamps.

Did you complete the repair?

--

System OK

--

9

Replace the faulty headlamps.

Did you complete the replacement?

--

System OK

--

10

  1. Disconnect the headlamp combination switch connector.
  2. Put the switch in the high-beam position.
  3. Use an ohmmeter to check the continuity of the headlamp switch between terminals 7 and 4 (terminal 2 if hatchback).

Does the ohmmeter indicate the specified value?

0 Ω

Go to Step 12

Go to Step 11

11

Replace the headlamp combination switch.

Did you complete the replacement?

--

System OK

--

12

Repair the open circuit between headlamp combination switch connector, terminal 4 (terminal 2 if hatchback), and Ef15.

Did you complete the repair?

--

System OK

--