Ok, I have a 2000 450es in my shop that is getting the best of me. I have just put a NEW ECM & the solenoid at the batt. that sends power to the ECM.
1st. -- After putting these on, still no response from the ES. Acts as if it's dead. I have power to the ECM(11.6v). When I push the the up or down shift buttons, I have nothing at the plug for the shift motor. I have power to the switches, and they ohm out good. I have power at the angle sensor. It ohms good. I don't know what to do.
2nd. -- After I let the the 4wheeler sit for a day and went back to work on it some more(I had to rbld the top of a rancher), NO power to ECM. This is the second solenoid(by the batt) that has gone bad while sitting with key off. What the heck??
Can one of you guys please help. You seem very good at this.. Many, many, thanks in advance...Ken

 

What are you using to check the power at the shift motor , I use a light bulb .. The older 450 ESP problems are harder to track down especially if you don't use the flow chart..

Here is 1 of the flowcharts I use and a few pictures of the tools I use for the 1998-01 450

================================================== ================================================== =================================
takes place of shift control motor


================================================== ================================================== =================================
takes place of angle sensor




================================================== ================================================== =================================

 

Thanx for the info. VERY useful...I guess I'm going with the Angle sensor. I thought it ohm'ed good but, after double checking it, it seems a little off. When I put the meter on the center prong and either one of the outer prongs I get a uneven reading while slowly turning it. It will go from 0 to 4.3 in jumpy movements. It's not a smooth climb in ohms as I turn it. And at other tests you can turn it nearly a 1/4 turn b-4 it even moves the meter.
Thanx again. I'll post the results when it gets here.

 

While I'm awaiting the Angle Sensor, I still don't understand the short I have causing the Relay(by the batt) to keep going bad. This is the third one. Any clues?? It's the relay that sends power to the ECM/ECU....

 

Nice Post HondaMechanic.

I had a 2001 Foreman and the es quit but I was lucky it was just the main fuses needed to be cleaned. My friend Bought the ATV so I saved this post for the future.

 

You can try a few things. Try a different shift control motor. If you don't have one, pull the existing shift control motor, rotate the motor a quarter of a turn and reinstall it. I see the diag path you are chasing. Been there done that. Seems as the system is seeing a problem and shutting down. If you keep tracing the power fault it will lead you to the CPU unit in the meter and leave you with your hands in the air and scratching your head what to do next. On the older 450 I have also found the speed sensor bad that will cause a simular diagnostic chase pattern. I don't know if it shorts in the sensor (no test) or what. The system just sees a problem and shuts down with no indication of what is going on. I would like to confirm that the shift control motor or speed sensor is the problem, with the unit as it is right now, not shifting at all, I can't tell you exactly what is going on because I almost need to know more circumstances which lead up to the issue.
Here is a buff. One of my quads is an 01 450 that had simular issues, that is why I purchased it so cheap. Every test I could find to do to the shift control motor showed it to be good. I have replaced every sensor, speed, gear position, shift angle, etc... even the shift switches, and it would still do the same thing you have run across on this one. I then installed a brand new shift control motor. The issue went away for a year and a half and does it on occasion again this summer.
Thoughts are focused right now around the relay. 4 wires, red yellow leading to the ECU, red white leading to the 15 amp fuse box motor fuse, black orange leads to the ECU and a green that taps into a ground wire which leads to the voltage regulator and chassis ground eyelet. Since the red wires have to do with the shift motor, the motor could have a bad spot in the armeture where the brushes sit idle in the same spot each time until a shift switch is depressed. Could have a shift motor brush hanging up or worn causing too much resistance in the system causing the ECU to shut down the whole system. It will do this through the realy as the black orange wire feeds power from the ECU to the relay on the power controlled magnetic switch inside the relay. The green ground wire is on the other side of this circuit so it is possible the voltage regulator has an internal issue affecting this ground to chassis (a power leak ?). I have not replaced the voltage regulator on my 450 so the door is open on this issue. Aslo looking at the green wire circuit shared between the 2 and chassis ground, this ground could be causing a problem at the frame terminal ? Easily checked if the ground terminal at the frame is removed and checked for a draw. Most likely not though. The voltage regulator ground wire issue internally might more likely worth looking into as it could be frying the relay by getting the magnetic coil winding inside of it hot. Eather way, from that ground circuit or the shift control motor is where I think the issue lies with your quad.
Once again I am super busy and better get back after it before I fall behind another month

Hope this helps you out

----- Gimpster -----

 

HondaMechanic this is in reference to a old post that you made in 2008

I have a 2000 TRX450ES that will not shift. I used the troubleshooting guide in the Honda service manual and the shop talk that you posted. In the shop talk it tells you to disconnect the Shift Switch, Gear Position Switch and the Speed Sensor. Turn the ignition key off, place in natural and turn the key on. Then attempt to shift using the shift buttons and the ECU should reset before entering fail mode. How can I tell if the ECU resets and how do I tell if it is in "FAIL" mode by the display? I believe it is a bad ECU because I could not get it to shift by jumping the shift switch in the next step. Any suggestions or ways to further check the ECU?