GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics and Interior Lights Schematics

1

Did you review Blackout (B/O) Lighting Description and Operation?

Go to Step 2

Go to Blackout Lighting Circuit Operation

2

  1. Place the blackout (B/O) service switch in blackout (B/O) mode.
  2. Connect a test lamp at cavity C of the blackout (B/O) switch and ground.

Does the test lamp illuminate?

Go to Step 3

Go to Step 6

3

  1. Disconnect the blackout (B/O) service switch connector from the switch.
  2. Connect a test lamp at cavity C of the connector and ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4

Replace the blackout (B/O) service switch. Refer to Blackout Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 9

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5

Locate and repair the short to voltage on circuit 912 (OG).

Did you complete the repair?

Go to Step 9

___

6

Remove the DRL interrupt relay from the relay module.

Are the DRLs illuminated?

Go to Step 8

Go to Step 7

7

Replace the DRL relay.

Did you complete the replacement?

Go to Step 9

___

8

Locate and repair the short to voltage on circuit 592 (L GN/BK).

Did you complete the repair?

Go to Step 9

___

9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2