GM Service Manual Online
For 1990-2009 cars only

Low/High Beam Headlamps Inoperative

Step

Action

Value(s)

Yes

No

1

Were you sent here from the DRL System Check?

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Go to Step 2

Go to DRL System Check

2

  1. Disconnect connector C209.
  2. Connect a DMM between connector C209 terminal W and ground.
  3. Measure the voltage at connector C209 terminal W.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 9

Go to Step 3

3

  1. Remove the HDLP Circuit Breaker #53 from the instrument panel electrical center.
  2. Connect a DMM between the instrument panel electrical center terminal A and ground.
  3. Measure the voltage at the instrument panel electrical center terminal A.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 4

Refer to Power Distribution

4

Connect a fused jumper (20 A) between the instrument panel electrical center terminals A and B which is used for the HDLP Circuit Breaker #53.

Does the 20 A fuse in the fused jumper open immediately?

--

Go to Step 5

Go to Step 6

5

Repair a short to ground in CKT 842.

Is the repair complete?

--

Go to DRL System Check

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6

  1. Leave the jumper in place.
  2. Connect a DMM between the headlamp switch connector C209 terminal W and ground.
  3. Measure the voltage at the headlamp switch connector C209 terminal W.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 8

Go to Step 7

7

Repair an open in CKT 842.

Is the repair complete?

--

Go to DRL System Check

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8

Replace the HDLP Circuit Breaker #53.

Is the repair complete?

--

Go to DRL System Check

--

9

  1. Reconnect connector C209.
  2. Using a DMM, backprobe connector C209 terminal L with the positive lead.
  3. Connect the negative lead to ground.
  4. Turn the headlamp switch to the ON position (headlamps on).
  5. Turn the dimmer switch to the low beam position.
  6. Measure the voltage at connector C209 terminal L.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 11

Go to Step 10

10

Replace the headlamp switch.

Is the repair complete?

--

Go to DRL System Check

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11

  1. Disconnect the underhood electrical center connector C2.
  2. Connect a DMM between the underhood electrical center connector C2 terminal D10 and ground.
  3. Measure the voltage at the underhood electrical center connector terminal D10.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 12

Go to Step 13

12

Replace the underhood electrical center .

Is the repair complete?

--

Go to DRL System Check

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13

Repair an open in CKT 11 and CKT 12.

Is the repair complete?

--

Go to DRL System Check

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