Hello, i have a 2
2007 3.5l chevy nalibu, i have a problem with the transmission shifting pretty hard. Its not all the time either, the past couple days it has been acting up more then usual. Today after about a 10 minute drive it started shifting very hard, it was jerking the whole car. I park wait a couple minutes and turn my csr back on. Shift into drive and it feels fine, turn the car off and turn it back on again and go back intro drive and then it shifts really hard again. Im thinking it has to do something with electrical? Trans fluid is looking good aswell. Any help would be much appreciated. Thanks!

 

check engine light on? If yes, have the codes read and post them.

if the car detects a slipping trans it will up the line pressure to protect the transmission...this creates hard shifts.

 

no cel, however when this problem happens the traction control light turns on. I find it weird though how it will fix itself if i just turn the car off and on. Could it be a sensor of some sort?

(EDIT) The car just threw two codes, u0073 and a p0171.

 

https://www.obd-codes.com/p0171
https://www.obd-codes.com/u0073

 

the loss of com code could put the trans into a failsafe mode. You need to post not only the code but what module the code is setting in and what module the code is setting for. ie pcm detects loss of com with tcm.