GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Remove the bulb from the left/right rear taillamp socket.
  2. Connect a DMM between the WHT wire attached to the bulb socket and chassis ground.

Does the DMM indicate continuity?

--

Go to Step 2

Go to Step 3

2

  1. Disconnect the harness connector from the left/right rear taillamp assembly.
  2. Connect a test lamp between terminal C of the harness connector and chassis ground.
  3. Operate the brake pedal.

Does the test lamp light?

--

Go to Step 4

Go to Step 5

3

  1. Disconnect the taillamp assembly harness connector.
  2. Connect a DMM between terminal E in the taillamp assembly harness connector and chassis ground.

Does the DMM indicate continuity?

--

Go to Step 7

Go to Step 6

4

Repair the open in the RED wire inside the taillamp assembly.

Is the repair complete?

--

System OK

--

5

Repair the open in CKT 18, 134 (YEL) / CKT 19, 135 (GRN) between the turn/hazard flasher module and terminal 5 (left) or 4 (right) in the taillamp assembly harness connector.

Is the repair complete?

--

System OK

--

6

Repair the open in CKT 150 (BLK) between S 402 and terminal E in the taillamp assembly harness connector.

Is the repair complete?

--

System OK

--

7

Repair the open in the white wire inside the taillamp assembly.

Is the repair complete?

--

System OK

--