GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Automatic Transmission Shift Lock Control System Check?

Go to Step 2

Go to Automatic Transmission Shift Lock Control System Check

2

  1. Place the manual selector in Park.
  2. Turn the ignition switch ON.
  3. Depress the brake pedal.
  4. Test for battery voltage at terminal 2 of the stoplamp switch. Refer to Circuit Testing in Wiring Systems.

Is battery voltage present?

Go to Step 10

Go to Step 3

3

Test for battery voltage at terminal 4 of the stoplamp switch. Refer to Circuit Testing in Wiring Systems.

Is battery voltage present?

Go to Step 4

Go to Step 5

4

Replace or adjust the stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

Go to Automatic Transmission Shift Lock Control System Check

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5

Test for battery voltage at terminal 9 of the transaxle range switch. Refer to Circuit Testing in Wiring Systems.

Is battery voltage present?

Go to Step 6

Go to Step 7

6

Repair the open in the ORN/BLK wire between the transaxle range switch and the stoplamp switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Automatic Transmission Shift Lock Control System Check

--

7

Test for battery voltage at terminal 8 of the transaxle range switch. Refer to Circuit Testing in Wiring Systems.

Is battery voltage present?

Go to Step 8

Go to Step 9

8

Replace the transaxle range switch. Refer to Transaxle Range Switch in Automatic Transmission.

Is the repair complete?

Go to Automatic Transmission Shift Lock Control System Check

--

9

Repair the open in the YEL wire between the transaxle range switch and the junction block. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Automatic Transmission Shift Lock Control System Check

--

10

  1. Place the manual selector in Park.
  2. Turn the ignition switch ON.
  3. Depress the brake pedal.
  4. Test for battery voltage at terminal 4 of the shift lock solenoid connector. Refer to Circuit Testing in Wiring Systems.

Is battery voltage present?

Go to Step 12

Go to Step 11

11

Repair the open in the ORN/WHT wire between the stoplamp switch and the shift lock solenoid. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Automatic Transmission Shift Lock Control System Check

--

12

Test for an open in the BLK wire between the shift lock solenoid connector and G400. Refer to Circuit Testing in Wiring Systems.

Is an open present?

Go to Step 13

Go to Step 14

13

Repair the open in the BLK wire between the shift lock solenoid and G400. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Automatic Transmission Shift Lock Control System Check

--

14

Replace the shift lock solenoid. Refer to Shift Lock Solenoid in Automatic Transmission.

Is the repair complete?

Go to Automatic Transmission Shift Lock Control System Check

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