Car jumping while in drive and stopped

[Lightz39]

So this has only happened twice and not for a while but I'm kind of curious. Twice now I've been in drive with the brakes on and my car will start to jump like a manual is about to stall. (Automatic) To fix the problem I throw it into park and back into drive. Any ideas on what it could be and if its serious?

[Jim Frye]

What year and model is it? Have you had it in for any software refreshes?

[Higgs Boson]

How fast are you going when you apply the brakes? How hard are you applying the brakes? What is the road surface when you apply the brakes?

Or are you stopped, like at a stop light/sign and the car begins to idle rough? What do you mean jumping? To me, that indicates the car is leaving the ground repeatedly. Is that the case?

[yabayb]

I'm having the same issue on my 2012 LT. It happenes when I'm stopped or just rolling (no gas), runs rough as if it's about to stall. Dropping it off tonight at the dealership and I'm back in a rental... AGAIN!

Just had the struts replaced in March, alignment fixed and rotors machined in May, not even @12,000 kms! Really?!?!?!

I've had too many problems on this BUY BACK!!

[Lightz39]

How fast are you going when you apply the brakes? How hard are you applying the brakes? What is the road surface when you apply the brakes?

Or are you stopped, like at a stop light/sign and the car begins to idle rough? What do you mean jumping? To me, that indicates the car is leaving the ground repeatedly. Is that the case?

Guess I could have put more details. I'm talking like stopped at a light. It just starts rocking similar to how a standard feels when its about to stall.

[Chevy Customer Service]

So this has only happened twice and not for a while but I'm kind of curious. Twice now I've been in drive with the brakes on and my car will start to jump like a manual is about to stall. (Automatic) To fix the problem I throw it into park and back into drive. Any ideas on what it could be and if its serious?

Lightz39,
I would suggest that you contact your local dealership and have them look into this for you. If you would like me to contact your dealer and set up an appointment for you please send me a PM with your name, phone number, VIN, dealer and the days and times that you are available. Either way, please keep me posted. If you have any questions please feel free to contact me anytime.
Thank you,
Stacy Chevrolet Customer Service

[Higgs Boson]

Does it do it with the AC on and off or just on? May people have noticed the AC compressor "vibrates" sometimes when it cycles on for a while. My car does it too. Of course, I can't say for sure what yours is doing. My keyboard can only check spark timing, not driveability concerns.

[Patman]

If it does it with the AC on, there is a sensor that increases the idle when the AC is turned on so the engine does not stall under the added load of the AC compressor. It is possible there is a problem with the sensor that adjusts the idle when the AC kicks on. On old carburated cars
the sensor advanced the throttle a little more.

Does it do it with the AC on and off or just on? May people have noticed the AC compressor "vibrates" sometimes when it cycles on for a while. My car does it too. Of course, I can't say for sure what yours is doing. My keyboard can only check spark timing, not driveability concerns.

[Bohdan]

Sounds like the torque converter may be binding.

[Higgs Boson]

If it does it with the AC on, there is a sensor that increases the idle when the AC is turned on so the engine does not stall under the added load of the AC compressor. It is possible there is a problem with the sensor that adjusts the idle when the AC kicks on. On old carburated cars
the sensor advanced the throttle a little more.

well, these days, that sensor is the ECU itself, and all it does it open the throttle blade a bit more to add a few grams of airflow. ;-)