GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Was A Diagnostic System Check performed?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Inspect the 20 Amp STOP HAZ fuse.

Is the STOP HAZ fuse open?

Go to Step 11

Go to Step 3

3

Use a test lamp in order to backprobe connector C1 of the brake switch connector between terminal A and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp light?

Go to Step 4

Go to Step 5

4

With the brake switch closed, Test for positive battery voltage at terminal B of connector C1. Refer to Circuit Testing in Wiring Systems.

Is voltage present?

Go to Step 6

Go to Step 7

5

Repair the open or short to ground in the Fuse Output-Battery between the fuse block and the brake switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

System OK

--

6

  1. Use a test lamp in order to backprobe the turn/hazard headlamp switch assembly connector C2 terminal A and ground.
  2. Depress the brake pedal.

Does the test lamp light?

Go to Step 8

Go to Step 9

7

Inspect the adjustment of the brake switch. If the adjustment is correct, replace the brake switch.

Is the repair complete?

System OK

--

8

Replace the turn/hazard headlamp switch assembly.

Is the repair complete?

System OK

--

9

Repair the open in Stop Lamp Switch Output between the brake switch and the turn/hazard headlamp switch assembly. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

System OK

--

10

With brake switch open test terminal A of the brake switch for continuity to ground. Refer to Circuit Testing in Wiring Systems.

Is ground present?

Go to Step 11

Go to Step 12

11

Repair short to ground in Fuse Output-Battery Circuit. Refer to Wiring Repairs in Wiring Systems.

Is repair complete?

System OK

--

12

Test the Stop Lamp Switch Output Circuit for continuity to ground. Refer to Circuit Testing in Wiring Systems.

Is ground present?

Go to Step 13

Go to Step 14

13

Repair short to ground in the Stop Lamp Switch Output Circuit. Refer to Wiring Repairs in Wiring Systems.

Is repair complete?

System OK

--

14

Test terminals F,G,B and C on the Hazard Warning Switch for continuity to ground. Refer to Circuit Testing in Wiring Systems.

Is ground present?

Go to Step 15

--

15

Repair short to ground in suspect CKT. Refer to Wiring Repairs in Wiring Systems.

Is repair complete?

System OK

--