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Q: Cannot shift out of park and the engine won't start

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I cannot shift the gear out of park and my engine also cannot start. I suspect this is the problem of bad transmission shift cable or bad transmission range sensor. How to differentiate between these two? Thank you

My car has 131000 miles.
My car has an automatic transmission.

A: Hello. The shift interlock system keeps you...

Hello. The shift interlock system keeps your car in park until you turn the key and step on the brake. It will not release the shifter until these two things occur.

The first thing you need to do is check all your fuses. Not just the fuses that would seem to power the suspected circuits, but all the fuses. We never know if another fuse or multiple fuses may power the suspected fuse that powers the shift interlock system. Check your brake lights. If they are not working, this indicates the brake light switch could be bad. The shift interlock is released when you push on the brake pedal.

The procedures following the brake lights and fuses require a test light, a wiring diagram and knowledge of electrical theory. There are several other components involved in the shift interlock system: the transmission range switch, the shift interlock relay, the shift interlock solenoid, and the ECM.

As far as the engine no crank condition, it is possible that these two are related, but it is also possible they are two different problems.

The transmission range switch could cause both of these problems. There is a small cover that can be removed on the left side of the shifter housing. Remove it, put the key in the ACC position. You can use a screw driver to release the shift interlock system manually.

Once you can move the shifter, put it into neutral and attempt to start the car. If it starts, this is a very strong indication you need a shift transmission range switch, also known as the neutral safety switch. If you can move the shifter freely once you manually unlock it, this confirms if the shift cable has any problems.

It’s important to note that if the motor cranks, then the this is a no start condition with other failures. If the motor does not crank, it is a no crank condition that could be related to the transmission range switch.

If you still require assistance with this, I recommend having a local expert, such as one from YourMechanic, diagnose the stating issue and shifting problem with your car so that both issues can be resolved.

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