GM Service Manual Online
For 1990-2009 cars only

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Action

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Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

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. Observe the turn signal lamps and indicators.
  3. Turn ON and OFF the right and left turn signal lamps.
  4. Turn OFF the ignition.

Do the turn signal lamps and indicators operate properly?

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

Go to Step 3

3

Are only the turn signal indicators always ON or flashing?

Go to Step 6

Go to Step 4

4

Test the turn signal lamps supply voltage circuit of the always ON or flashing turn signal bulb for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 5

5

  1. Disconnect the turn signal/hazard flasher module.
  2. Connect a test lamp between the always ON or flashing turn signal cornering lamp supply voltage circuit of the turn signal/hazard flasher module and a good ground.
  3. Turn OFF the always ON or flashing turn signal.

Does the test lamp illuminate?

Go to Step 7

Go to Step 8

6

  1. Disconnect the component with the always ON or flashing turn signal indicator.
  2. Connect a test lamp between the turn signal lamps supply voltage circuit of the always ON or flashing turn signal indicator and the ground circuit of the always ON or flashing turn signal indicator.
  3. Turn OFF the always ON or flashing turn signal.

Does the test lamp illuminate?

Go to Step 12

Go to Step 11

7

Test the always ON or flashing turn signal cornering lamp supply voltage circuit of the turn signal/hazard flasher module for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 10

8

Test the ignition voltage circuit 1 of the turn signal/multifunction switch for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 9

9

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 16

Go to Step 13

10

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 14

11

Inspect for poor connections at the harness connector of the component with the always ON or flashing turn signal indicator. 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 the short to voltage in the turn signal lamps supply voltage circuit of the always ON or flashing turn signal indicator. 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/hazard flasher module. Refer to Hazard Lamp Flasher Replacement .

Did you complete the replacement?

Go to Step 16

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14

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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15

Replace the component with the always ON or flashing turn signal indicator. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console and Outside Rearview Mirror Glass Replacement in Doors.

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 2