GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

    • Ensure that the ignition switch is in RUN.
    • Ensure that the gear selector is in park.
    • Ensure that stoplamp/BTSI switch connector C1 is disconnected.
    • Press the brake pedal and hold.
    • Move the gear selector to NEUTRAL.

Does the gear selector shift to neutral?

--

Go to Step 3

Go to Step 2

2

    • Ensure that the shift interlock actuator is disconnected.
    • Connect the test lamp between terminal A (DK GRN/WHT) and ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems.

Does the test lamp light?

--

Go to Step 7

Go to Step 5

3

    • Test stoplamp/BTSI switch connector C1 for proper terminal contact.
    • Repair the connector as necessary. Refer to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step  4

--

4

Replace the stoplamp/BTSI switch. Refer to Brake Transmission Shift Interlock Replacement in Automatic Transmission - 4T65-E or to Brake Transmission Shift Interlock Solenoid Replacement in Automatic Transmission - 4T80-E.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

5

    • Test shift interlock actuator connector for proper terminal contact.
    • Repair the connector as necessary. Refer to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 6

--

6

Replace shift interlock actuator.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

7

Repair a short to B+ in CKT 1135 (DK GRN/WHT). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

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