Revving rpm issue when braking

[JuliaBoston]

Hi,
I have 2015 CX-5 and about a month ago had an issue when breaking or neutral gear RPM went up at every stop and when break was released it shakes and moves forward with all force. When RPM went up there was a sound as if I am pressing a gas pedal which I was not. I took it to mechanic and he reset the computer and the issue went away. First when I took it to autozone the issue appeared something to do with air filter but after the reset it was all good.
A month later the same issue is occurring and I took it back to the mechanic and his computer is not showing any issues so we are not sure what to fix.
Anyone had similar issues? Mazda dealerships dont have any appointments for several days and I am scared to drive it thanks!

 

[craigo]

It's normal during some braking for RPM's to go up - the transmission downshifts and uses engine vacuum to help slow the car, leading to better stopping performance and longer brake pad life. This kind of engine braking is common with manual transmissions but relatively new in the world of automatics.

That said it would be unusual to see it at every stop. I wonder if a sensor is on the fritz and reporting bad data, leading to this engaging when it should not. You may need to end up at the Mazda dealer, or someone with a lot of experience on these vehicles to track it down.

 

[JuliaBoston]

Thank you! Yes, I guess it could be some system bug and taking to a dealership is the only option but wanted to check if someone also experienced such issue.
When RPMs go up its load and seems to be out of our control and its scary to release the brakes at the stop lights as I dont know how fast if will go

 

[craigo]

It sounds like the issue is more like rising RPM's at idle than to do with braking. Could be a vacuum leak.

 

[GAXIBM]

Make sure you don't have a floormat or something on top of the gas pedal giving it gas without your foot pressing.

 

[Jwassall]

The idle on my 2015 CX-5 rises to about 1,500 rpms sometimes when I am stopped at a light. I have taken it to 2 dealers and talked to Mazda USA about it and they say it is normal.

 

[Chris_Top_Her]

get it documented by the dealer b4 your warranty is up rip