Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Shift Interlock Systems: Description
The transmission shift interlock system prevents driver from moving gear selector from Park unless ignition switch is turned to ON position, and prevents ignition key from being removed until gear selector is returned to Park. On models equipped with Brake Transmission Shift Interlock (BTSI) solenoid, gear selector cannot be moved from Park while ignition is on until brake pedal is depressed. This prevents accidental movement of gear selector from Park while engine is running. BTSI solenoid is located in steering column or center console.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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