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 or Data Communication Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Turn ON the hazard flashers.

Does the system operate normally?

Go to Testing for Electrical Intermittents

Go to Step 3

3

  1. Turn ON the ignition with the engine OFF.
  2. Turn ON each turn signal.

Do the turn signals function properly?

Go to Step 4

Go to Turn Signal Lamps and/or Indicators Inoperative

4

With a scan tool, monitor the Hazard Lamp Switch data parameter in the Body Control Module (BCM) data list while pressing the switch several times.

Does the scan tool display Active and Inactive?

Go to Step 8

Go to Step 5

5

Test the hazard switch signal circuit for an open, high resistance or short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 6

6

Test the ground circuit of the multifunction switch for high resistance or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 7

7

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

Did you find and correct the condition?

Go to Step 11

Go to Step 9

8

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

Did you find and correct the condition?

Go to Step 11

Go to Step 10

9

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

Did you complete the replacement?

Go to Step 11

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10

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

Did you complete the replacement?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3