GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) 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

Do the high beam headlamps operate properly?

Go to Step 3

Go to Headlamps Inoperative - High Beams

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Flash to Pass Switch parameter in the instrument panel module (IPM) inputs list.
  4. Turn the flash to pass switch ON and OFF several times.

Does the Flash to Pass Switch parameter change from ACTIVE to INACTIVE as the switch is cycled?

Go to Step 8

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the C4 harness connector at the turn signal/multifunction switch.
  3. Connect a 3-amp fused jumper wire between the flash to pass switch signal circuit and ground circuit at the turn signal/multifunction switch C4 harness connector.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the Flash to Pass Switch parameter in the IPM inputs list.

Does the scan tool indicate the Flash to Pass Switch parameter is ACTIVE?

Go to Step 7

Go to Step 5

5

Locate and repair an open or high resistance in the flash to pass switch ground circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 6

6

Locate and repair an open, high resistance, or short to voltage in the flash to pass switch signal circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 8

7

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 .

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 IPM. 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 turn signal/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 IPM. 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 2