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Crosstrek sudden acceleration while braking

Why pulling into a parking spot at the local Walmart with the foot on the brake the car suddenly accelerated. Why holding firmly on the brake the car slammed into a concrete base of a light post. The car is A 2014 Subaru Crosstrek. Wondering if anyone else has had a similar problem with there Crosstrek. The air bags never deployed. I feel the should have due to the amount of damage on the front of the car. I am going to be contacting Subaru on the matter at hand.

Good luck with that

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Taking a wild guess…I think that the vacuum hose to the “Brake Booster” became disattached somehow.

As far as the air bags…I have no idea except that you may not have been going fast enough to deploy them.
At least you will only need body work anf not all new air bags!!!


I would think you have full insurance coverage on a 2014 so let your insurance handle this .You will pay the deductible and may get it back some day. During the repair a problem may be found but don’t count on it.

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I don’t belive it would be the brake booster hose… I don’t believe that that would make the motor rev up and the car to take off.

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Actually, it would. But, to be blunt, it is more likely you accidentally hit the gas.


You either stepped on the accelerator or the edge of your foot caught the accelerator when you stepped on the brake. Either way, a car will not accelerate with your foot on the brake.

Your airbag deploys based on readings from a decelerometer sensor. When your rate of deceleration hits a certain threshold the airbags deploy. Despite your heavy collision, the impact did generate enough g-force to trip the sensor, hence no air bag deployment.

Air bag deployment has nothing to do with the amount of damage to the car. In fact, the damage is usually a result of the car absorbing the impact as it was designed to do, as happened in this case.

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Using Walmart where we live is a necessary thing to do . When I go there or anywhere else I park at the far end of the lot and pull through the space. That way I don’t have anyone around me or anything in front of me. That also allows me to drive forward and not have to back up . And the extra walking is good for me.


99% of all cases like this are either floor mats getting jammed or unintentional gas pedal pushing.


I was a passenger in my friend’s Accord sedan in 2008 when it was T-boned by a crazy woman driver in a Lexus SUV. Needless to say, the Accord was totaled, but we escaped serious injuries.

I overheard the cops interviewing that woman after the accident, and she said, “the harder I pressed on the brake, the faster the car went”. The cop muttered… Yeah, that’s what happens when you hit the gas instead of the brake… lists few Subaru stories about “I pressed on the brakes, it ran even faster”, so I read it with a grain of salt, but as former multi-Subaru owner I will tell one of the reasons why I stopped buying them: they changed the design of the lower part of a dashboard the way where my feet would regularly bump into some plastic panel above and end up laying on both brakes&gas pedals, I felt it unsafe

I don’t want to start the whole unintended acceleration thing again but while it is likely a mat, confusion, etc., there are other possibilities. Engine speed is now controlled electronically by the computer and sensors. A computer glitch, dirty idle air control, cruise control activating, and so on could cause the engine to speed up. So I think a check up is needed.

Many years ago, I experienced a slight surge in idle speed when pulling into my garage, and it proved to be a dirty IAC.

Revving of the engine by a faulty IAC, etc. will not overcome properly working brakes.


That is an excellent point.

True if the OP was forcefully applying the brakes. But OP may have been only pushing on brake pedal lightly, bc they were just pulling into a parking spot, not decelerating from freeway speed so to stop at the stoplight at the end of a downhill off-ramp.

Accelerating when stepping on the brake, the car is designed and tested so as to make sure even if a part fails that doesn’t happen, and such a thing rarely does happen fortunately. But no design is perfect and I concur with the above posts, it makes sense to get the car looked at by a pro. They’ll look at the accelerator pedal and brake pedal ass’ys, the throttle’s electronic actuator and relay, at the carpets & mats, old coca cola cans rolling around, assess if something like that was involved, etc, and test/inspect the IAC (or drive by wire ass’ys) and brake booster for anything that might be wrong. My guess, the most likely explanation is the accelerator pedal was pushed by something either directly or indirectly while you were stepping on the brake pedal.

If that happened to me I’d remove all the carpets/mats from the driver’s area, give the whole interior a good clean out and vacuuming (esp under the seats), and remove anything inside the passenger compartment that wasn’t there when the car was purchased new. All the extraneous stuff ( stuff that most of us in our cars), I’d put that all in the trunk for the time being. I’d also probably drive wearing plain ordinary tennis shoes and switch to formal or better shoes when leaving the car. On a temporary basis I mean, untill the problem is eventually discovered.

Re: airbags. Hard to say whether they should have deployed or not. It is quite expensive to replace deployed airbags with new ones, so you avoided a big expense there by them not popping, if you are a “silver lining” sort of person. . If you think the airbag system may be faulty, hire a pro to perform the air bag test procedure.

I don’t know about you, but I adjust the pressure I put on the brake pedal based on how the car is stopping.

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Depends on the dynamics of the situation probably. OP’s car may have only been 2-3 feet from the lamp post when they noticed the unintended acceleration. No disagreement that forcefully stepping on the brake pedal should be able to prevent forward motion even with the throttle engaged.

If you are pulling into a parking stall, you have light pressure on the brakes to come to a slow and even stop. Then if all of a sudden the car lurches forward, it is likely to overcome the light pressure you have on the brake pedal. Normally you want to come to a smooth stop, in fact in driver’s ed back in 1964 we were taught to actually let up on the pedal a little just before you stop in order to avoid the car jerking. Just seems to make sense that if the rpms all of a sudden increased, you wouldn’t be ready for it.

My guess is that both of the OP’s feet were slightly to the right of where she thought they were. When your left foot is under the left edge of the brake pedal and rour right foot if bridging the right edge of the brake pedal and the left edge of the gas pedal, the sensation is exactly as described.

How do I know, It has happened to me with my size 14s and having jobs where I frequently changed cars.

I never hit anything, only because I knew that what I thought I was feeling couldn’t be happening and took corrective action.