GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights 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

  1. Turn OFF the ignition.
  2. Observe the park lamps.
  3. Turn the park lamps ON and OFF.

Do the park lamps operate properly?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with engine OFF.
  3. Verify the park lamps are turned OFF.
  4. With the scan tool, observe the Park Lamp Switch parameter in the Dash Integration Module (DIM) Inputs data list.

Does the Park Lamp Switch data parameter display OFF?

Go to Step 4

Go to Step 5

4

  1. Expose the sunload sensor to a bright light.
  2. Wait more than 20 seconds.
  3. Turn OFF the park lamps.
  4. With a scan tool, command the parking lamps relay ON and OFF from the DIM Special Functions, Output Control data list.

Did all of the park lamps turn ON and OFF?

Go to Step 13

Go to Step 6

5

  1. Turn OFF the ignition.
  2. Disconnect the multifunction, turn signal switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the Park Lamp Switch parameter.

Does the Park Lamp Switch data parameter display OFF?

Go to Step 11

Go to Step 9

6

  1. Turn OFF the ignition.
  2. Disconnect the park lamp relay. Refer to Relay Replacement .
  3. Turn ON the ignition, with the engine OFF.

Do the park lamps turn OFF?

Go to Step 7

Go to Step 14

7

  1. Turn OFF the ignition.
  2. Connect a test lamp between the park lamp relay control circuit of the park lamp relay and the coil side supply voltage circuit of the park lamp relay.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool command the parking lamps relay ON and OFF.

Did the test lamp turn ON and OFF?

Go to Step 12

Go to Step 8

8

Test the control circuit of the park lamp relay for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 18

Go to Step 10

9

Test the park lamp switch on signal circuit of the multifunction, turn signal switch for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 18

Go to Step 10

10

Test the backlight lamps control circuit of the DIM for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 18

Go to Step 13

11

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

Did you find and correct the condition?

Go to Step 18

Go to Step 15

12

Inspect for poor connections at the park lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 18

Go to Step 16

13

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

Did you find and correct the condition?

Go to Step 18

Go to Step 17

14

Repair the short to voltage in the park lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 18

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15

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

Did you complete the replacement?

Go to Step 18

--

16

Replace the park lamp relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 18

--

17

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

Did you complete the replacement?

Go to Step 18

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18

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2