I tired sending this to Gimpster, but his box is full and he has not been here for awhile. Hopefully someone else can help.

Gimpster --
I have read your posts on the Honda Foreman 450ES (at least the ones I have found), and they have been very helpful. THANK YOU! I am still a little confused though.

A little background:
I have a 1998 450-ES that is not shifting. Going through all the "service manual" tests points me to the ECU. But from your posts, it is clear the service manual is a bit lacking in completeness of testing.
One of your suggested tests was to insert a light in the circuit inline before the shift motor. I put it inline and had no light. Looking at the circuit, I figured I could pull the motor out of circuit, and replace it using a 4-7W, 12V bulb to determine if the ECU was good. I got no light.
HOWEVER, I then saw a post where you included something from Honda Shop Talk. In there, it discusses FAIL mode. I am assuming it is possible that the ATV simply went into fail mode prior to these tests, right? How can you tell if it is FAIL mode when looking at the troubleshooting guide? I have not yet tried these tests, because I am unclear about how to tell when it enters FAIL mode versus nothing happening.
If you cannot tell, I am attempting to confirm that it is the ECU before putting out the $350 for one and then discovering that it was okay.

Thank you!!

 

To others who are in the same boat: I had a mouse cause some destruction on a few wires by the 30A fuse. I fixed it. But then I was testing with only 12V 40A battery power. That was not sufficient. Simply by using a better battery, I was able to go through all the tests Gimpster outlined, and then, I was able to get it to shift again.

So, when people say to test with a fully charged battery, make certain the fully charged battery is actually capable of full output and that your copper wires are still heavy enough gauge, or your ECM is going to jump into failover mode.