GM Service Manual Online
For 1990-2009 cars only

Headlight Doors Inoperative-One Door

Step

Action

Value(s)

Yes

No

DEFINITION: One or both headlamp opening door actuators are inoperative.

1

Has the Headlight Doors System Check been performed?

--

Go to Step 2

Go to Headlight Doors System Check

2

Remove and inspect the inoperative headlamp door actuator fuse for an open.

    • HDLP MOT LH #4
    • HDLP MOT RH #3

Is the fuse open?

--

Go to Step 13

Go to Step 3

3

  1. Disconnect the headlamp opening door actuator control module connector C1.
  2. Connect a test light from the connector terminal,
  3. • B to ground. (LH inop.)
    • E to ground. (RH inop.)

Does the test light illuminate?

--

Go to Step 4

Go to Step 12

4

  1. Reconnect the headlamp opening door actuator control module connector C1.
  2. Disconnect the inoperative headlamp opening door assembly connector.
  3. Connect a test light between the harness side connector terminal A and ground.
  4. Turn the headlamp switch on and off.

When the headlamp switch is turned off, does the test light illuminate?

--

Go to Step 5

Go to Step 6

5

  1. Connect a test light between the harness side headlamp opening door assembly connector terminal B and ground.
  2. Turn the headlamp switch on.

When the headlamp switch is turned on, does the test light illuminate?

--

Go to Step 11

Go to Step 7

6

  1. Disconnect the headlamp opening door actuator control module connector C2.
  2. Connect a DMM from the inoperative headlamp opening door assembly connector terminal A, to the headlamp opening door actuator control module connector C2,
  3. • terminal B. (LH inop.)
    • terminal C. (RH inop.)
  4. Measure the resistance of the door actuator up feed circuit.

Is the resistance within specified values?

0-2 ohms

Go to Step 7

Go to Step 8

7

  1. Connect a DMM from the inoperative headlamp opening door assembly connector terminal B, to the headlamp opening door actuator control module connector C2,
  2. • terminal A. (LH inop.)
    • terminal D. (RH inop.)
  3. Measure the resistance of the door actuator down feed circuit.

Is the resistance within specified values?

0-2 ohms

Go to Step 10

Go to Step 9

8

Repair the open or high resistance in circuit,

    • 577. (LH inop.)
    • 579. (RH inop.)

Is the repair complete?

--

Go to Headlight Doors System Check

--

9

Repair the open or high resistance in circuit,

    • 576. (LH inop.)
    • 578. (RH inop.)

Is the repair complete?

--

Go to Headlight Doors System Check

--

10

Replace the headlamp opening door control module. Refer to Headlamp Control Module Replacement .

Is the repair complete?

--

Go to Headlight Doors System Check

--

11

Replace the inoperative headlamp opening door actuator assembly. Refer to Headlamp Motor/Actuator Replacement .

Is the repair complete?

--

Go to Headlight Doors System Check

--

12

Repair the open or high resistance in circuit,

    • 2940. (LH inop.)
    • 3040. (RH inop.)

Is the repair complete?

--

Go to Headlight Doors System Check

--

13

Repair the short to ground in circuit,

    • 2940. (LH inop.)
    • 3040. (RH inop.)

Is the repair complete?

--

Go to Headlight Doors System Check

--