How Long Does a Shifter Interlock Solenoid Last?

Moving the gear shift from park to drive or reverse lets you move the car when you’re ready, but what happens if you bump the shifter accidentally and aren’t ready to roll? In older cars, this was a very real problem. However, newer models don't have that problem thanks to the shifter interlock solenoid.

Basically, the shifter interlock solenoid is a switch designed to lock your transmission into park unless the brake pedal is pushed. If you try to shift your car out of park without also holding the brake pedal down, you’ll find that it won’t move. This is a safety precaution and is installed on all automatic transmission cars manufactured in the last few decades (classic cars don’t have this feature).

The shifter interlock solenoid should last for the life of your vehicle, but premature failure is not that uncommon. When it happens, the shifter won’t move out of park, even with your foot on the brake. As a note, the same thing will happen if your brake light switch fails, or if something happens to your brake light circuit. It’s illegal and very unsafe to drive without brake lights, so a safeguard has been built into your car to prevent that from happening (note that this won’t do anything if the brake light bulb burns out – it only applies to the circuit itself). If the brake light switch fails (and it does happen), then the shifter interlock solenoid will prevent you from putting the car in drive.

Given the importance of the shifter interlock solenoid, it’s important that you know the signs to watch for that may indicate it’s about to fail, or has already given up the ghost. These include:

  • Shifter won’t move out of park (can indicate a failed solenoid, or a failed brake light switch)

  • Shifter is hard to move out of park (indicates a problem with the solenoid, but not complete failure)

  • You have to use the interlock bypass to get the transmission out of park

If you suspect that your shifter interlock solenoid is about to fail, or has already failed, the mobile mechanics at YourMechanic can help. A mechanic will come to your location, inspect and replace the shifter interlock solenoid, the brake light switch and other components if needed.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How Long Does an Evaporator Temperature Sensor (Switch) Last?
If If you have air conditioning in your vehicle, which pretty much all modern vehicles have, then you have an evaporator temperature sensor (switch). This switch plays an important role in making sure the correct temperature is attained, and that...
How to Replace an AC Pressure Switch
The AC pressure switch protects the AC system from pressure that's too high or low. Common signs of failure include a bad compressor or lack of AC.
How to Replace a Front Axle Engagement Switch on Most Cars
The switch that engages the front axle fails when it gets stuck, does not activate the four-wheel drive, or is difficult to engage.

Related questions

How do I open and close the sun roof?
If your car is equipped with a sun roof, then it is opened and closed via a switch on the overhead console. The sun roof has two switches on the overhead console: the switch closest to the driver controls the...
Key locked in ignition
Hi, over time the tumblers in the lock cylinder can wear out or get debris lodged preventing rotation. The notches on the key also wear out over time which doesn't fully unlock all of the tumblers preventing the key from...
Performance issues when driving and idling, RPM dropping abruptly
The symptoms you are describing are almost always caused by a bad catalytic converter (https://www.yourmechanic.com/services/catalytic-converter-replacement). When this fails it clogs the exhaust, which causes these problems to occur. Do a back pressure test on the exhaust first. If that is...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com