GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the headlight system check preformed?

--

Go to Step 2

Go to Headlight System Check

2

  1. Check the bulbs for opens.
  2. check the connectors for opens.

Are the bulbs and/or connectors open?

--

Go to Step 3

Go to Step 4

3

  1. Replace bulbs.
  2. Repair connections.

Is the repair complete?

--

Go to Headlight System Check

--

4

  1. Turn the headlamps on.
  2. Turn the headlamp dimmer switch to the High position.
  3. Using a test lamp backprobe the underhood accessory wiring junction block harness connector C3 terminal D11 to ground and also terminal C8 to ground.

Is the test lamp on?

--

Go to Step 5

Go to Step 6

5

Using a test lamp backprobe the underhood accessory wiring junction block harness connector C2 terminal F10 to ground.

Is the test lamp on?

--

Go to Step 7

Go to Step 8

6

Using a test lamp backprobe the underhood accessory wiring junction block harness connector C3 terminal F1 to ground and also terminal F2 to ground.

Is the test lamp on?

--

Go to Step 9

Go to Step 8

7

Using a test lamp backprobe connector C201 terminal L to ground.

Is the test lamp on?

--

Go to Step 11

Go to Step 10

8

Replace the underhood accessory wiring junction block. Refer to Underhood Fuse Block Replacement for service procedure.

Is the repair complete?

--

Go to Headlight System Check

--

9

  1. Repair open in circuit 1201 between the underhood accessory wiring junction block connector C3 terminal E11 to connector C141 terminal G and underhood accessory wiring junction block connector C3 terminal C8 to connector C142 terminal G.
  2. Repair open in circuit 1640 between the underhood accessory wiring junction block connector C3 terminal F1 to connector C141 terminal H.
  3. Repair open in circuit 1740 between the underhood accessory wiring junction block connector C3 terminal F2 to connector C142 terminal H.

Is the repair complete?

--

Go to Headlight System Check

--

10

Repair the poor connection or open in circuit 1201 of the underhood accessory wiring junction block harness connector C2 terminal F10 to Connector C201 terminal L.

Is the repair complete?

--

Go to Headlight System Check

--

11

Replace the headlamp switch. Refer to Multifunction Turn Signal Lever Replacement - On Vehicle for service procedure.

Is the repair complete?

--

Go to Headlight System Check

--