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 Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Verify that the park, license and tail lamps are inoperative.

Do the park, license and tail lamps operate normally?

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

Go to Step 3

3

Are all park, license, and tail lamps inoperative?

Go to Step 6

Go to Step 4

4

Test the supply circuit of the inoperative lamp for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 5

5

Test the ground circuit of the inoperative lamp for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 14

6

  1. Remove the park lamp relay.
  2. Install a jumper between the coil side supply circuit and the switch side circuit of the park lamp relay.

Do the park lamps illuminate?

Go to Step 7

Go to Step 13

7

  1. Remove the jumper.
  2. Reinstall the park lamp relay.
  3. Disconnect the body control module (BCM) connector C1.
  4. At the BCM connector, install a jumper between the park lamp relay control circuit and ground.

Do the park lamps illuminate?

Go to Step 9

Go to Step 8

8

Test for a poor connection or a short to battery positive voltage open in the park lamp relay control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 15

9

  1. Reconnect the BCM connector C1.
  2. Disconnect the multifunction turn signal switch.
  3. At the multifunction switch connector, install a jumper between the park lamp switch ON signal circuit and ground.

Do the park lamps illuminate?

Go to Step 10

Go to Step 11

10

Inspect for poor connections at the harness connector of the multifunction turn signal switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 16

11

Test for a poor connection, open, or a short to ground in the park lamp switch on the signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 12

12

Inspect for poor connections at the harness connector of the BCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 17

13

Repair a short to ground, open, or a poor connection in the park lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 18

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14

Replace the inoperative bulb.

Did you complete the replacement?

Go to Step 18

--

15

Replace the park lamp relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the repair?

Go to Step 18

--

16

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

Did you complete the repair?

Go to Step 18

--

17

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 18

--

18

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3