2005 Honda Rancher Reverse Shift Popping

I own a 2005 Honda Rancher TRX400A5. it's well used but I'm running into a problem. When I shift it into reverse then throttle it up it won't move and the system "pops" several popping noises per min. the "ESP" lamp is flashing once then twelve times befor starting the process over again. I have changed all for of the wheel sensors (like the dealer said) I also have a set of directions to syncronize them

1. turn unit key to "on"
2. hold BOTH shift switches for ten seconds
3. hold in the "UP SHIFT" button for 10 seconds.
3. hold the "down shift" button for the same
4. rev eng for 10 seconds.

That doesn't work.
What now??

I'll see if I can get some suggestions from a friend of mine who has a Rancher.

* I added the year, make, and model of atv into your thread, to get better responses.

thank you for the edit AJMboy.

I should have mentioned that all the sensors have been replaced and she rides just fine going forward. however if I start and need to go in reverse it doesn't like that so much. it'll move, but not at all very well. Honda says something is out of tune. The calibration directions they gave me just don't work.

I bought it localy from a shop but he doesn't have the knowlege or desire to fix my problem. Not having a trailer is proving to be a problem.

I know that some machines have a rev limiter that keeps the vehicle from running too fast in reverse, if yours has one, it could be part of the problem, just an outside thought. Or maybe one of the new wheel sensors is faulty. I would double check every thing you have done, make sure all connections are solid.

Dognight5, did you ever find a solution for this?