Rancher TRX400FA 2006 Stuck in Fail-Safe Mostly

Hi Guys, new to the forum. Found you while searching for a solution to a ECM/shifting problem with a 2006 TRX400FA. This problem seems like one that a person smart on how the system works will know where to start, so I am throwing this out for help. Melsman’s write up gave me a lot of good info and ideas, but I’m hoping someone will just know.

Background, first, the bad: machine is only used for plowing snow in Pittsburgh PA. It sits for 9 months on a battery tender looking lonely and sad. I just like 2-wheeled fun better, but I love how this thing plows my driveway.

The better: It’s only got 800 miles on it. Get’s loving oil changes, tune ups, all the right care. Have a Service Manual and use it.

So it starts fine, but when I shift into Drive (Auto) or Reverse, it shows "- -". It stays in low gear all the time. First time, it had a Code of 11 (ECM Fail-Safe Relay Circuit). Followed the book, which said to reset it. Did that, and it has never come back, but the problem is the same. So now there are no more ECM codes being thrown.

In ESP, no gear number appears and the switches do not function.

Occasionally, once when driving stuck in low and once coming out of N, it started working normally (both D and R), but this was short-lived, next time in N and come back out, stuck in low. I’d say I’ve tried it 30 times at it worked twice.

My thought is trouble shoot the Control Motor and the Angle Sensor, but I can’t figure out why it would go into gear at all if that was the problem, but that could be the "fail-safe" design so it gets you home at 3 MPH. Those of you who understand the system will probably not find that surprising.

Any thoughts will be much appreciated, thanks.

Jeff