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

1

Did you perform the Lighting System 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 left and right turn signals.

Do the turn signals operate properly?

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

Go to Step 3

3

Are only the left side turn signals or only the right side turn signals inoperative?

Go to Step 9

Go to Step 4

4

Is one of the turn signal indicators inoperative?

Go to Step 6

Go to Step 5

5

Place the hazard switch to the ON position.

Do the hazard lamps operate properly?

Go to Step 12

Go to Step 8

6

  1. Disconnect the instrument panel cluster (IPC).
  2. Turn ON the ignition, with the engine OFF.
  3. Probe the voltage supply circuit of the inoperative indicator with a test lamp that is connected to a good ground.
  4. Place the turn signal switch to operate the turn signals of the inoperative side.

Does the test lamp illuminate and flash?

Go to Step 10

Go to Step 7

7

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

Did you find and correct the condition?

Go to Step 16

Go to Step 11

8

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

Did you find and correct the condition?

Go to Step 16

Go to Step 11

9

Inspect for poor connections at the harness connector of the turn signal multifunction 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 16

Go to Step 13

10

Inspect for poor connections at the harness connector of the IPC. 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 16

Go to Step 14

11

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 15

12

Repair an open or high resistance in the turn/hazard request circuit between splice 270 and the turn signal multifunction switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

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13

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

Did you complete the replacement?

Go to Step 16

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14

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

Did you complete the replacement?

Go to Step 16

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15

Important: Perform the set up procedure for the Body Control Module (BCM). Refer to Body Control Module (BCM) Programming/RPO Configuration Body Control System.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 16

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16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3