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

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Ensure that the brake pedal is not depressed.

Do the stop lamps remain OFF?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Disconnect the body control module (BCM) connector C2.

Does one stop lamp stay illuminated?

Go to Step 5

Go to Step 4

4

Test for a short to voltage in the stop lamp supply voltage circuit of the electronic brake control module (EBCM). Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 7

Go to Step 6

5

Repair a short to battery positive voltage in the voltage supply circuit of the illuminated stop lamp. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 7

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6

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 7

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7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3