GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Important: A short to ground will cause an open fuse(s). Before performing this diagnostic procedure, inspect the fuse(s) for an open.

1

  1. Place the headlamp switch in the ON position.
  2. Use a test lamp in order to backprobe the underhood junction block between terminal A 12 of connector C3 and ground.

Does the test lamp light?

--

Go to Step  2

Go to Step  3

2

Use a test lamp in order to backprobe the turn/headlamp switch assembly between terminal 34 of the turn/headlamp switch assembly connector C1 and ground.

Does the test lamp light?

--

Go to Step  4

Go to Step  5

3

Replace the underhood junction block. Refer to Relay/Fuse Center Replacement in Wiring Systems

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

4

Test CKT 150 for an open.

Was a condition found?

--

Go to Step  6

Go to Step  5

5

Replace the turn/headlamp switch assembly. Refer to Multifunction Turn Signal Lever Replacement - On Vehicle in Steering Wheel and Column -Tilt.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

6

Repair the open in CKT 150. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

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