GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Is the problem the left side turn signals?

--

Go to Step 2

Go to Step 9

2

Remove and inspect the lt TURN fuse.

Is the fuse open?

--

Go to Step 3

Go to Step 4

3

Locate and repair CKT 2114 (LT BLU) for a short to ground.

Is the repair complete?

--

System OK

--

4

  1. Re-install the fuse.
  2. Turn ignition to the ON position.
  3. Turn left turn signal on.
  4. Connect a scan tool.
  5. Using the scan tool, read the left turn signal input in the body control module (BCM).

Does the scan tool show ON?

--

Go to Step 5

Go to Step 6

5

Locate and repair the open in CKT 2114 (LT BLU) between the mid bussed electrical center (MBEC) and the LT TURN fuse.

Is the repair complete?

--

System OK

--

6

Connect a test lamp (back probe) from terminal A7 of C201A to ground.

Does the test light/flash?

--

Go to Step 8

Go to Step 7

7

Replace the turn/hazard switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt.

Is the repair complete?

--

System OK

--

8

Locate and repair the open in CKT 14 (LT BLU) between the switch and the MBEC.

Is the repair complete?

--

System OK

--

9

Remove and inspect the RT TURN fuse.

Is the fuse open?

--

Go to Step 10

Go to Step 11

10

Locate and repair CKT 2115 (DK BLU) for a short to ground.

Is the repair complete?

--

System OK

--

11

  1. Re-install the fuse.
  2. Turn ignition to the ON position.
  3. Turn right turn signal on.
  4. Connect a scan tool.
  5. Using the scan tool, read the right turn signal input in the BCM.

Does the scan tool show ON?

--

Go to Step 12

Go to Step 13

12

Locate and repair the open in CKT 15 (RT BLU) between MBEC and the RT TURN fuse.

Is the repair complete?

--

System OK

--

13

Connect a test lamp (back probe) from terminal A6 of C201A to ground.

Does the test light/flash?

--

Go to Step 15

Go to Step 14

14

Replace the turn/hazard switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt.

Is the repair complete?

--

System OK

--

15

Locate and repair the open in CKT 15 (RT BLU) between switch and MBEC.

Is the repair complete?

--

System OK

--