GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you review the Exterior Lights Circuit Description and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

Verify that the stoplamps are inoperative.

Are the stoplamps inoperative?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Test for battery voltage at terminal 1 of the stoplamp switch.

Is battery voltage present?

Go to Step 5

Go to Step 4

4

Repair the open in the GRN wire between the stoplamp switch and S241. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 10

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5

Test for battery voltage at terminal 2 (M/T) or terminal 3 (A/T, M/T w/cruise) of the stoplamp switch.

Is battery voltage present with the brake pedal depressed?

Go to Step 7

Go to Step 6

6

Adjust or replace the stoplamp switch. Refer to Stop Lamp Switch Adjustment or Stop Lamp Switch Replacement in Hydraulic brakes.

Is the repair complete?

Go to Step 10

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7

  1. Disconnect C205.
  2. Test for battery voltage at terminal 9 with the brake pedal depressed.

Is battery voltage present?

Go to Step 9

Go to Step 8

8

Repair the open in the GRN/WHT wire between the stoplamp switch and C205. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 10

--

9

Repair the open in the GRN/WHT wire between the C205 and S304. Refer to Wiring Repairs in Wiring Systems.

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