GM Service Manual Online
For 1990-2009 cars only

Stop Lamps Inoperative Pickup/Utility Except Export

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the stoplamps are inoperative.

Do the stop lamps operate normally?

--

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

Go to Step 3

3

Inspect the STOP LP 20A fuse in the Underhood Fuse Block.

Is the fuse open?

--

Go to Step 4

Go to Step 5

4

Locate and repair short to ground in CKT 1540 (ORN), 17 (WHT), 1418 (YEL/BLK) or 1419 (DK GRN/WHT). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 10

--

5

  1. Remove the Stoplamp Switch and install a fused jumper between the connector terminal A and terminal B.
  2. Connect a test lamp from ground to terminal E7 or terminal E6 of connector C211. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 6

6

Test for open or high resistance in CKT 17 (WHT) or CKT 1540 (ORN). Refer to Circuit Testing in Wiring Systems.

Was a problem found?

--

Go to Step 8

Go to Step 9

7

Adjust or replace the Stoplamp Switch.Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair Complete?

--

Go to Step 10

--

8

Repair the open or high resistance in CKT 17 (WHT) or CKT 1540 (ORN). Refer to Wiring Repairs in Wiring Systems.

Is the repair Complete?

--

Go to Step 10

--

9

Replace the Multifunction Switch (Turn Signal Switch). Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Standard or Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle Steering Wheel and Column - Tilt.

Is the repair Complete?

--

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3

Stop Lamps Inoperative Export

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the stoplamps are inoperative.

Do the stop lamps operate normally?

--

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

Go to Step 3

3

Does the High Mount Stop Lamp operate properly?

--

Go to Step 4

Go to Stop Lamps Inoperative - Center High Mounted

4

Inspect the bulb for an open filament.

Was a problem found?

--

Go to Step 5

Go to Step 6

5

Replace the defective bulb.

Is the repair complete?

--

Go to Step 9

--

6

Connect a test lamp from ground to terminal A of either inoperative Tail/Stoplamp socket and apply the service brake. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 8

7

Locate and repair the open or high resistance in CKT 1350 (BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

8

Locate and repair the open or high resistance in CKT 1320 (LT BLU). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3