GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you perform the Lighting Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn ON the ignition, with the engine OFF.
  2. Operate the turn signal switch in both the left and right hand turn signal positions.

Does the turn signal system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

3

Are all turn signal lamps inoperative?

Go to Step 7

Go to Step 4

4

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

Go to Step 14

Go to Step 5

5

Is only the turn signal indicators inoperative?

Go to Step 15

Go to Step 6

6

Is only one turn signal lamp inoperative?

Go to Step 16

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7

Operate the hazard switch.

Are the hazard lamps inoperative?

Go to Step 8

Go to Step 11

8

With the multifunction switch still connected, connect a test lamp between the turn/hazard module signal circuit of the multifunction switch and a good ground.

Does the test lamp flash on and off?

Go to Step 19

Go to Step 9

9

Test the ground circuit of the turn/hazard flasher for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 10

10

Test the turn/hazard module signal circuit for high resistance, an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 17

11

Connect a test lamp between the turn/hazard module 2 supply voltage circuit of the turn/hazard flasher and a good ground.

Does the test lamp illuminate?

Go to Step 17

Go to Step 12

12

Test the turn/hazard module 2 supply voltage circuit of the turn/hazard flasher for high resistance, an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 13

13

Test the ignition 1 voltage circuit of the turn/hazard switch for high resistance, an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 19

14

Test the appropriate turn signal circuit for high resistance, an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 19

15

  1. Disconnect the instrument cluster connector.
  2. Connect a test lamp between the appropriate turn signal indicator lamp supply voltage circuit and a good ground.
  3. Turn ON the ignition, with the engine OFF.
  4. Turn the turn signal switch to the appropriate turn signal on position.

Does the test lamp illuminate with the turn signal?

Go to Step 18

Go to Step 20

16

Test the appropriate turn signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 21

17

Inspect for poor connections at the harness connector of the turn hazard flasher connector. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 22

18

Inspect for poor connections at the harness connector of the instrument cluster connector. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 23

19

Inspect for poor connections at the harness connector of the turn/hazard switch. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 24

20

Repair the high resistance or an open in the turn signal indicator lamp circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

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21

Replace the turn signal lamp assembly. Refer to Parking and Turn Signal Lamp Replacement or Tail/Turn Signal Lamp Replacement .

Did you complete the replacement?

Go to Step 25

--

22

Replace turn/hazard flasher.

Did you complete the replacement?

Go to Step 25

--

23

Replace the lamp or the instrument cluster as necessary.

Refer to Instrument Cluster Bulb Replacement or Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 25

--

24

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

Did you complete the replacement?

Go to Step 25

--

25

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3