GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the Exterior Lighting System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

Place the hazard switch in the ON position.

Do the hazard signals operate properly?

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

Go to Step 3

3

  1. Turn the ignition 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 signals operate?

Go to Step 10

Go to Step 4

4

Inspect the T/SIG fuse and the HAZARD fuse for an open.

Are the T/SIG fuse and the HAZARD fuse open?

Go to Step 17

Go to Step 5

5

  1. Turn the ignition to the OFF position.
  2. Disconnect the hazard lamp/turn signal flasher.
  3. Place the hazard flasher switch in the ON position.
  4. Probe the supply voltage circuit of the hazard lamp/turn signal lamp flasher connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 7

6

Probe the ground circuit of the hazard lamp/ turn signal flasher connector with a test lamp that is connected to battery voltage.

Does the test lamp illuminate?

Go to Step 8

Go to Step 18

7

Backprobe the turn/hazard module supply voltage circuit of the C201 connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 15

Go to Step 13

8

Install a fused jumper between the supply voltage circuit and the signal circuit of the hazard lamp/ turn signal flasher connector. Refer to Circuit Testing in Wiring Systems.

Do the turn signal lamps illuminate?

Go to Step 12

Go to Step 9

9

  1. Leave the fused jumper connected.
  2. Backprobe the turn signal flasher signal circuit of the C201 connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 13

Go to Step 14

10

Using a test lamp connected to ground, backprobe the battery positive voltage circuit of the C201 connector that is fed by the HAZARD fuse.

Does the test lamp illuminate?

Go to Step 13

Go to Step 11

11

Test for an open or high resistance in the battery positive voltage circuit of the C201 connector that is fed by the HAZARD fuse. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 16

12

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

Did you find and correct the condition?

Go to Step 21

Go to Step 19

13

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

Did you find and correct the condition?

Go to Step 21

Go to Step 20

14

Repair an open or high resistance in the turn signal flasher circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

15

Repair an open or high resistance in the turn/hazard module supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

16

Repair the short to ground in the battery positive voltage circuit of the C201 connector that is fed by the HAZARD fuse. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

17

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

    • The turn/hazard module supply voltage circuit
    • The turn signal flasher signal circuit
    • The front turn signal switch signal circuit Domestic
    • The turn lamp supply voltage circuit

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

18

Repair the open or high resistance in the ground circuit of the hazard lamp/turn signal flasher. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

19

Replace the hazard lamp/turn signal flasher.

Has the repair been made?

Go to Step 21

--

20

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

Is the repair complete?

Go to Step 21

--

21

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2