GM Service Manual Online
For 1990-2009 cars only

LO Beams Inoperative

Step

Action

Value(s)

Yes

No

1

Were you sent here from the DRL Diagnostic System Check?

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Go to Step 2

Go to DRL Diagnostic System Check

2

  1. Turn the headlamp switch to the ON position (headlamps on).
  2. Turn the headlamp dimmer switch to the low beam position.
  3. Use a DMM and backprobe between C209 terminal L and ground.
  4. Measure the voltage at C209 terminal L.

Is the voltage within the specified values?

--

Go to Step 4

Go to Step 3

3

Replace the headlamp switch.

Is the repair complete?

--

Go to DRL Diagnostic System Check

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4

  1. Disconnect the underhood electrical connector C2.
  2. Connect a DMM between the underhood electrical connector C2 terminal D3 and ground.
  3. Turn the headlamp switch to the ON position (headlamps on).
  4. Turn the headlamp dimmer switch to the low beam position.
  5. Measure the voltage at the underhood electrical connector C2 terminal D3.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 6

Go to Step 5

5

Repair the open in CKT 12 between the underhood electrical connector C2 and connector C209.

Is the repair complete?

--

Go to DRL Diagnostic System Check

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6

Replace the underhood electrical center.

Is the repair complete?

--

Go to DRL Diagnostic System Check

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