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. Ensure that the hazard flashers are OFF.
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the turn signal lamps and indicators.
  4. Turn ON and OFF the right and left turn signals.

Do the turn signal lamps and indicators operate properly?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Are only the turn signal indicators always ON?

Go to Step 10

Go to Step 4

4

Is only one lamp on at all times?

Go to Step 5

Go to Step 6

5

Test for a short to voltage in the appropriate turn signal supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 8

6

Disconnect the multifunction turn signal switch.

Do the turn signal lamps turn off?

Go to Step 9

Go to Step 7

7

Test for a short to ground in the appropriate turn signal switch signal circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 8

8

Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 11

9

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

Did you find and correct the condition?

Go to Step 14

Go to Step 12

10

Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 13

11

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

Did you complete the replacement?

Go to Step 14

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12

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

Did you complete the replacement?

Go to Step 14

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13

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

Did you complete the replacement?

Go to Step 14

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14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2