GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn the ignition switch to the ON position.
  2. Place the turn signal switch in the LH ON position.
  3. Place the turn signal switch in the RH ON position.
  4. Determine if any of the turn signals or turn signal indicators are inoperative.

Are the turn signals and indicators operating properly?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Are all of the turn signals and indicators inoperative?

Go to Step 4

Go to Step 5

4

Press the hazard switch to the ON position.

Do all of the hazard lamps operate?

Go to Step 6

Go to Step 14

5

Are only the instrument panel (I/P) turn signal indicators inoperative?

Go to Step 12

Go to Step 8

6

  1. Disconnect the turn signal switch.
  2. Install a jumper between the turn signal switch ground circuit and the left turn signal switch circuit.

Do the left turn signal lamps illuminate?

Go to Step 13

Go to Step 7

7

Test for an open, poor connection, or a short to battery positive voltage in the ground circuit of the turn signal switch. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 15

8

Are only the hazard lamps inoperative?

Go to Hazard Lamps Inoperative

Go to Step 9

9

Are both the front and rear turn signal lamps inoperative on one side?

Go to Step 10

Go to Step 16

10

  1. Disconnect the multifunction turn signal switch connector C2.
  2. Install a jumper between the turn signal switch ground circuit and the inoperative side turn signal switch circuit.

Do the turn signal lamps illuminate?

Go to Step 13

Go to Step 11

11

Test for a poor connection, an open, or a short to battery positive voltage in inoperative turn signal switch circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 21

Go to Step 15

12

Replace the instrument panel cluster (IPC). Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 21

--

13

Replace the multifunction turn signal switch. Refer to Turn Signal Multifunction Switch Replacement .

Is the replacement complete?

Go to Step 21

--

14

Test for a poor connection, an open, or a short to ground in the LT and RT T/SIG fuse circuit of the body control module (BCM). Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 21

Go to Step 15

15

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the repair?

Go to Step 21

--

16

  1. Disconnect the inoperative turn signal lamp.
  2. Place the turn signal switch to the inoperative side.
  3. Using a test lamp connected to ground, probe the turn signal supply voltage circuit.

Does the test lamp flash?

Go to Step 17

Go to Step 19

17

Using a test lamp connected to the turn signal supply voltage circuit, probe the turn signal lamp ground circuit.

Does the test lamp flash?

Go to Step 20

Go to Step 18

18

Repair a poor connection, an open, or a short to battery positive voltage in the ground circuit of the turn signal lamp. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 21

--

19

Test for a poor connection, an open, or a short to ground in the turn signal lamp voltage supply circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 21

Go to Step 15

20

Replace the inoperative turn signal lamp.

Did you complete the repair?

Go to Step 21

--

21

  1. Connect all connectors and components that were previously disconnected.
  2. Verify that the turn signal lamps and indicators operate properly.

Do the turn signal lamps and indicators operate properly?

System OK

Go to Step 3