GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Headlight Doors Diagnostic System Check?

--

Go to Step 2

Go to Headlight Doors System Check

2

  1. Turn OFF the headlamp switch.
  2. Disconnect the headlamp opening door actuator control module connector C1.
  3. Measure the voltage between the headlamp opening door actuator control module connector C1 terminal C and ground.

Is the voltage within the specified range?

10.0-14.0V

Go to Step 3

Go to Step 6

3

Test for continuity in CKT 150 between the headlamp opening door actuator control module connector C1 terminal D and ground.

Is continuity present in CKT 150 to ground?

--

Go to Step 5

Go to Step 4

4

Repair the open in CKT 150.

Is the repair complete?

--

Go to Headlight Doors System Check

--

5

Replace the headlamp opening door actuator control module.

Is the replacement complete?

--

Go to Headlight Doors System Check

--

6

  1. Disconnect the underhood electrical center connector C3.
  2. Test CKT 306 for continuity between the underhood electrical center connector C3 terminal B6 and the headlamp opening door actuator control module connector C1 terminal C.

Is continuity present in CKT 306 between these connectors?

--

Go to Step 7

Go to Step 10

7

  1. Disconnect the underhood electrical center connector C2.
  2. Measure the voltage between the underhood electrical center connector C2 terminal E6 and a good ground.

Is the voltage within the specified range?

10.0-14.0V

Go to Step 8

Go to Step 9

8

Replace the underhood electrical center.

Is the repair complete?

--

Go to Headlight Doors System Check

--

9

  1. Disconnect connector C209.
  2. Test for continuity in CKT 306 between the underhood electrical center connector C2 terminal E6 and connector C209 terminal T.

Is continuity present in CKT 306 between these connectors?

--

Go to Step 11

Go to Step 10

10

Repair the open in CKT 306.

Is the repair complete?

--

Go to Headlight Doors System Check

--

11

Replace the headlamp switch.

Is the replacement complete?

--

Go to Headlight Doors System Check

--