GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the Exterior Lighting Systems Description and Operation and perform the necessary inspections?

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Go to Step 2

Go to Exterior Lighting Systems Description and Operation

2

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

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

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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 IP cluster inoperative?

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Go to Step 4

Go to Step 6

4

Test the inoperative turn signal switch signal circuit to the IP cluster for an open or high resistance. Refer to Circuit Testing in Wiring Systems.

Did you find a problem?

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Go to Step 14

Go to Step 5

5

  1. Inspect the inoperative bulb/socket in the IP cluster for poor terminal contact or an open filament and replace as necessary. Refer to Instrument Cluster Bulb Replacement .
  2. If a problem is not found, replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console.

Did you complete the repair?

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Go to Step 23

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6

Is only one turn signal lamp inoperative?

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Go to Step 7

Go to Step 8

7

Inspect the inoperative bulb/socket for an internal short, poor terminal contact, or an open filament.

Did you find a problem?

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Go to Step 19

Go to Step 15

8

Inspect the TURN fuse in the IP fuse block.

Is the fuse open?

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Go to Step 13

Go to Step 9

9

  1. Turn the ignition and start switch to the RUN position
  2. Test the ignition 1 voltage circuit to the hazard warning switch for voltage. Refer to Circuit Testing in Wiring Systems.

Is the specified voltage present?

B+

Go to Step 10

Go to Step 16

10

  1. Activate the multifunction turn signal switch.
  2. Test the turn signal flasher control circuit for voltage at the multifunction turn signal switch. Refer to Circuit Testing in Wiring Systems.

Is the specified voltage present?

B+

Go to Step 12

Go to Step 11

11

Test for an open or high resistance in the turn signal flasher control circuit. Refer to Circuit Testing in Wiring Systems.

Did you find a problem?

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Go to Step 17

Go to Step 21

12

  1. Disconnect the multifunction turn signal switch.
  2. Place the multifunction turn signal switch in the inoperative turn position.
  3. Test the multifunction turn signal switch for continuity between the multifunction turn signal switch turn signal flasher control circuit input terminal and the inoperative turn signal switch signal output terminal. Refer to Circuit Testing in Wiring Systems.

Is continuity present?

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Go to Step 21

Go to Step 20

13

Test the following circuits for a short to ground, and refer to Circuit Testing in Wiring Systems:

    • The ignition 1 voltage
    • The turn signal flasher control
    • The left turn signal switch signal
    • The right turn signal switch signal

Did you find a problem?

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Go to Step 18

Go to Step 21

14

Repair the open or high resistance in the inoperative turn signal switch signal circuit to the IP cluster. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

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Go to Step 22

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15

Repair the problem in the supply voltage circuit, or in the ground circuit of the turn signal lamp . Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

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Go to Step 22

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16

Repair the open or high resistance in the ignition 1 voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

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Go to Step 22

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17

Repair the open or high resistance in the turn signal flasher control circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 22

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18

Repair the short to ground found in one of the following circuits, and refer to Wiring Repairs in Wiring Systems:

    • The ignition 1 voltage
    • The turn signal flasher control
    • The left turn signal switch signal
    • The right turn signal switch signal

Did you complete the repair?

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Go to Step 22

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19

Replace or repair the inoperative bulb/socket.

Did you complete the repair?

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Go to Step 22

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20

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

Did you complete the repair?

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Go to Step 22

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21

Replace the hazard warning switch. Refer to Hazard Warning Switch Replacement .

Did you complete the repair?

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Go to Step 22

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22

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3