I have a 2011 MDX which has been experiencing trans problems. Surging at about 40-45 miles an hour 1700 rpm. Took to my local mechanic and he stated that trans was not locking in 4th 5th or 6th gear. Took to the local Acura dealer and their mec also stated that was a trans problem. They talked to Acura and stated they want to do an computer upgrade before replacing trans. Just called and stated that new firmware has fixed prob. Have not driven it yet car has 58,000 miles. Always worked on but Acura dealers till it went out of warranty. Thoughts.

 

Sounds like the torque converter to me. If you search here on AZ you will find threads describing the same surging you mention.

 

Did this firmware upgrade really solve your problem, OP? Hope everything worked out for you.

 

When we had the software update, IMHO all it did was change the shift points and sort of mask the issue.

 

Interesting. Never thought about that.