GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the left or right turn signal lamps are inoperative.

Do the turn signal lamps operate normally?

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

Go to Step 3

3

  1. Disconnect the inoperative bulb.
  2. Inspect the bulb.
  3. Repeat this test as needed for each inoperative bulb.

Is the bulb open?

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Go to Step 4

Go to Step 5

4

Replace the bulb.

Is the repair complete?

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Go to Step 10

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5

With the Multifunction Switch (Turn Signal Switch) activated, connect a test lamp from ground and terminal A at the inoperative lamp socket. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

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Go to Step 7

Go to Step 6

6

Locate and repair the open, high resistance or short to ground in the Turn Signal Lamp Fused Supply Voltage circuit to the inoperative socket. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 10

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7

  1. Connect a test lamp between terminal A and the ground terminal of the inoperative lamp socket. Refer to Circuit Testing in Wiring Systems.
  2. Turn the ignition switch to the RUN position.
  3. Select the appropriate direction on the Multifunction Switch (Turn Signal Switch).

Does the test lamp illuminate?

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Go to Step 8

Go to Step 9

8

Replace the bulb.

Is the repair complete?

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Go to Step 10

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9

Locate and repair the open or high resistance in the ground circuit to the inoperative lamp socket. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3