What would the electrical problem be

 

Does it shift properly, by manually shifting, as noted above?

 

No it does not

 

Came to the site looking for answers and found this post. I’m having similar issues. I have a 08 h3 with 146K. I did transmission and filter change around 100k. I only have problems up shifting from 3 to 4, according to the diagram from the earlier post. I feel a small vibration and sometimes a jerk as it shifts. Sometimes the jerk is pronounce and sometimes it’s not. I can say it starts at around 45mph and stops when it shifts around 50. Any thoughts or help is appreciate as I want my hummer to last a long time!

TIA

 

This could also be caused by an engine performance issue. Any codes stored? Did you check fluid level at operating temp? Do you still feel the vibration driving in 3rd at 45-50mph? Did you check the color of the trans fluid?

 

Add a can of seafoam to the transmission, make sure to check fluid level at operating temp, drive for awhile, then get a transmission fluid flush.

https://seafoamsales.com/product/tra...uid-treatment/

 

Will try the Seafoam. No codes and the vibration only happens sometimes.

 

Also monitor the color of the trans fluid on a paper towel, as I posted above. Seafoam is a great cleaner, then flush it out. I've corrected many trans shifting issues this way. GL

 

So, I'm back. My transmission fluid seem fine as it was still red in color. I took your advice and put some seafoam in and flush the fluid. Also, changed out the filter while I was there. It seemed better since then and would rarely jerk or vibrate during shifting. Yesterday as I was during, felt the vibration again and got the CEL. I'm now throwing 2 codes. A P0700 Transmission Cntrl system malfunction and the other is P0741 Torque Converter Ckt Perf/Stuck Off. Any thoughts? I read it may be 2 solenoids in the transmission, the transmission control module, or the torque converter. Any help on where to start?

Thanks All!

 

Transmission is low on fluid.