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 in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Depress the brake pedal.

Do all of the stop lamps illuminate?

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

Go to Step 3

3

Is only one lamp inoperative?

Go to Step 4

Go to Step 7

4

  1. Disconnect the imperative lamp.
  2. Using a test lamp connected to ground, probe the stop lamp supply voltage circuit.
  3. Depress the brake pedal.

Does the test lamp illuminate?

Go to Step 6

Go to Step 5

5

Test for a poor connection, open, or a short to ground in the stop lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

6

Test for a poor connection or an open in the ground circuit of the inoperative stop lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

7

  1. Disconnect the brake pedal position sensor.
  2. Using a test lamp connected to the battery positive voltage, probe the brake pedal position sensor low reference circuit.

Does the test lamp illuminate?

Go to Step 10

Go to Step 8

8

Test for a poor connection or an open in the low reference circuit of the brake pedal position sensor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

9

Replace the inoperative stop lamp. Refer to High Mount Stop Lamp Replacement or Tail Lamp, Turn Signal Lamp, High Mount Stop Lamp, License Lamp, Backup Lamp Replacement - Rear .

Did you complete the repair?

Go to Step 11

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10

Replace the body control module (BCM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the repair?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3