Hi all,

I own a 2015 Fit LX CVT, purchased 8 months ago with about 12000 miles on it. Lately I have been experiencing an issue while braking that I was hoping someone could shed some light on.

I tend to drive my car very gently, and usually brake quite delicately. Over the last few months I have noticed what feels like the brakes suddenly engaging with more force and then immediately releasing, usually while traveling at around 10 mph, causing the whole car to “jolt” shortly before stopping. I have found that this jolt always occurs when then engine rpm drops from roughly 1100, to idle at about 750, leading me to believe it is more an issue with the engine or the transmission than the brakes.

The jolt does not always occur with the same intensity. Most of the time a passenger in the car probably would not even notice it unless they were looking for it. Occasionally it is enough to topple items stored in the trunk. I have not found any obvious preference for this occurring while going uphill or downhill.

My hypothesis is that the engine is being used to provide some braking force, which is then diminished once the engine drops to idle, but that does not explain what feels like a sudden increase in braking force, followed immediately by a release.

I have already taken my car to the dealer regarding the issue, and while I was not able to be present for the test drive, they found no obvious mechanical issues. I have never owned a car with a CVT before, but I can’t imagine that this phenomenon is part of its nominal operation. If anyone has any suggestions regarding how to go about diagnosing or solving this issue, it would be greatly appreciated.

Thanks!!

 

Are you aware that a bit below 1000rpm, DFCO (deceleration fuel cut-off) is deactivated which causes the injectors to fire back up and in turn reduces engine braking. This could make it feel a little like the brakes release.

 

Drive it harder.

 

As GoBucky said, the car decelerates more with engine braking because the fuel injectors are shut off. As you're coming to a stop, the transmission is "downshifting" to be ready to take off again as well as to keep the unfiring engine up to speed, and it's more noticeable. To keep the engine running at idle speed below where the torque converter unlocks, the fuel injectors start firing again and that engine braking is lost right before you stop. IOW, it's normal.