GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views or Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gages, and Console

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the turn signal lamps and/or indicators are inoperative.

Do the turn signal lamps and/or indicators operate normally?

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

Go to Step 3

3

Are only the turn signal indicators in the instrument panel cluster (IPC) inoperative?

Go to Step 4

Go to Step 5

4

Test the inoperative turn signal supply voltage circuit to the IP cluster 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 18

Go to Step 11

5

Is only 1 turn signal lamp inoperative?

Go to Step 6

Go to Step 7

6

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

Did you find and correct the condition?

Go to Step 18

Go to Step 15

7

Inspect the IGN E fuse and the FLASHER fuse in the underhood fuse block.

Is either fuse open?

Go to Step 10

Go to Step 8

8

Test for an open or high resistance in the following circuits. Refer to Circuit Testing and Wiring Repairs in Wiring Systems:

    • The turn/hazard flasher battery positive supply voltage
    • The turn/hazard flasher ground
    • The turn signal switch ignition 1 supply voltage

Did you find and correct the condition?

Go to Step 18

Go to Step 9

9

  1. Disconnect the multifunction switch turn signal switch.
  2. Test the multifunction turn signal switch for continuity between the multifunction turn signal switch ignition 1 voltage input terminal and the left or right turn signal switch signal output terminal in each respective position. Refer to Circuit Testing in Wiring Systems.

Is continuity present?

Go to Step 10

Go to Step 12

10

Test the following circuits for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems:

    • The multifunction turn signal switch ignition 1 voltage
    • Left or right turn signal indicator lamp supply voltage
    • Left or right front turn signal lamp supply voltage
    • Left or right mirror turn signal lamp supply voltage
    • Left or right rear turn signal lamp supply voltage
    • Left or right rear stop/turn lamp supply voltage
    • Left or right DRL/turn supply voltage
    • Left or right turn signal switch signal
    • Turn/hazard flasher module battery positive voltage

Did you find and correct the condition?

Go to Step 18

Go to Step 13

11

Inspect for poor connections at the IPC. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 14

12

Inspect for poor connections at the multifunction turn signal switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 16

13

Inspect for poor connections at the turn/hazard flasher. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 17

14

Important: Perform the set up procedure for the IPC.

Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console.

Did you complete the repair?

Go to Step 18

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15

Replace or repair the inoperative bulb/socket.

Did you complete the repair?

Go to Step 18

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16

Replace the multifunction turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.

Did you complete the repair?

Go to Step 18

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17

Replace the hazard/turn flasher. Refer to Hazard and Turn Signal Flasher Replacement .

Did you complete the repair?

Go to Step 18

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18

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3