GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn the ignition switch to the RUN position.
  2. Place the turn signal switch in the LH ON position.
  3. Place the turn signal switch in the RH ON position.

Do the turn signal operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Inspect the T/SIG fuse.

Is the fuse open?

Go to Step 4

Go to Step 5

4

Repair a short to ground in one of the following circuits:

    • CKT 539
    • CKT 1508

Is the repair complete?

Go to Step 15

--

5

  1. Turn the ignition switch to the RUN position.
  2. Use a test lamp in order to backprobe between C201 terminal A2 and ground.

Did the test lamp light?

Go to Step 7

Go to Step 6

6

Repair the following conditions in CKT 539:

    • A faulty connection
    • An open circuit

Is the repair complete?

Go to Step 15

--

7

Use a test light in order to backprobe between connector C201 terminal E1 and ground.

Does the test light illuminate?

Go to Step 9

Go to Step 8

8

  1. Replace the turn signal switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle
  2. Inspect the system.

Is the repair complete?

Go to Step 15

--

9

Use a test light to backprobe the hazard lamp/turn signal flasher between connector terminal A1 and connector terminal B2.

For EXPORT vehicles backprobe the hazard lamp/turn signal flasher between connector terminal 2 and connector terminal 5.

Does the test light illuminate?

Go to Step 11

Go to Step 10

10

Repair the following conditions, as needed:

    • A faulty connection or an open in CKT 1508
    • A faulty connection or an open in CKT 1450 between B2 and ground

Has the repair been made?

Go to Step 15

--

11

  1. Remove the hazard lamp/turn signal flasher.
  2. Domestic: Connect a fused jumper between the hazard lamp/turn signal flasher connector terminal C1 and A1.
  3. Export: Connect a fused jumper between the hazard lamp/turn signal flasher connector terminal 2 and 4.
  4. Place the turn signal switch to the LH ON position.
  5. Place the turn signal switch in the RH ON position.

Do the appropriate turn signals illuminated when the tun signal switch is turned ON?

Go to Step 12

Go to Step 13

12

Replace the turn signal/hazard lamp flasher.

Has the repair been made?

Go to Step 15

--

13

Use a test light in order to backprobe the turn signal switch harness connector C201 terminal A4 to ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 14

14

Repair the faulty connection or the open in CKT 16.

Has the repair been made?

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2