GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the entire Headlight Door System Check performed?

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Go to Step  2

Go to Headlight Doors System Check

2

  1. Disconnect the headlamp opening door actuator control module connector C1.
  2. Connect a test light between the headlamp connector terminal E or B and ground.
  3. Turn the headlamp switch to the HEAD position.

Does the test light illuminate?

9 - 14 V

Go to Step  3

Go to Step  4

3

  1. Disconnect the headlamp opening door actuator control module connector C2.
  2. Disconnect C160 (LH) or C165 (RH).
  3. Check for a short to B+ in circuits 576 and 577 (LH) or 578 and 579 (RH).

Is a short to B+ present?

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Go to Step  5

Go to Step  6

4

Check for a short to ground in circuits 576 and 577 (LH) or 578 and 579 (RH).

Is a short to ground present?

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Go to Step  7

Go to Step  8

5

Repair a short to B+.

Is the repair complete?

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Go to Step  13

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6

Check for continuity in circuits 576 and 577 (LH) or 578 and 579 (RH).

Is there continuity?

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Go to Step  9

Go to Step  10

7

Repair the short to ground.

Is the repair complete?

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Go to Step  13

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8

Repair the open in circuit 840 or 740.

Is the repair complete?

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Go to Step  13

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9

  1. Reconnect the headlamp door actuator control module connectors C1 and C2.
  2. Place the headlamp switch in the HEAD position.
  3. Using a test light probe between the inoperative motor connector terminals A and B.

Does the test light illuminate?

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Go to Step  11

Go to Step  12

10

Repair the poor conection or open.

Is the repair complete?

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Go to Step  13

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11

Replace the inoperative headlamp door motor.

Is the repair complete?

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Go to Step  13

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12

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

Is the repair complete?

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Go to Step  13

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13

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

Have all the repairs been made?

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Go to Headlight Doors System Check

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