We purchased this 2016 Pilot with 101000 miles in March of this year from a VW dealer. We had the car 3 days when we were caught in stop and go traffic. After about 15 minutes the trans would slam in and out of 3rd to 4th gear 2 or three times and finally stop slamming once the car was going over 25mph. It happened 5 or six times until we got home. I called the VW dealer and they arranged to have the car checked at the Honda dealer the next day and gave us a loaner. I found two service bulletins about flushing the trans fluid 3x and updating the firmware. I printed these and brought them to the Honda dealer. The next morning the car was fine on the drive to the dealer. I also had Honda replace the timing belt and install a trans fluid cooler since we planned to tow a travel trailer. The dealer was not able to duplicate the problem and there were no trouble codes, so they did the trans flush and firmware update and gave the car back. We drove the car for 6 weeks with no problem, even towed the travel trailer, then out of the blue it happened again. The Honda dealer said bring it back and again gave us a loaner. The dealer tried to duplicate the problem for a week with no success. The second service bulletin for this transmission said to again flush the fluid 3x and make sure the firmware was updated. The dealer finally agreed to do this again and gave us the car. Fast forward two months, towing the travel trailer on I75 through Atlanta we hit stop and go traffic that lasted for over an hour. 10 minutes into this delay the problem started and never stopped. I finally had the chance to troubleshoot the problem. I’m hoping someone who knows how this transmission works can figure out what’s going on. First the slamming in and out of gear starts when you try to accelerate from a stopped position. The slam is from 3rd to fourth gear, 2 or three times with a second or two interval between slams. I put the trans into L and no slamming, the shift from stop to 3rd is working. The instant I put the trans into D the trans slams into 4th, every time. I drove like this for 20 min and when the traffic finally started moving, 5th and 6th gear were gone. The trans wouldn’t shift out of 4th gear. The D4 button didn’t do a thing. The D4 displayed on the dash but the trans refused to shift out of 4th. This lasted 2 hours until we got to the destination. The next morning the trans was back to normal operation, no check engine trouble code or any indication of a problem. How is this possible? Please help!!!