We're having real problem with my 2006 800C. The problem is that the engine idles at very low RPM (like 500rpm) and will not speed up, as the EC Motor (step motor) will not operate the throttle cable to speed up the engine. The cable is fine and operates easily and smoothly and when manually moved by hand the engine speed will increase, so we know that isnt the problem. So far we have changed the MIC controller (which piggy backs on top of the Pump and Valve controller) as that was heavily corroded inside and when that didn't work, we changed the EC motor but that didnt help either. The motor is getting current to it, although it sounds as if the current is too low to advance the throttle cable and so the engine will not speed up when we turn the engine speed dial. We've tested the wire harness snd seems okay so the problem seems to be that the EC Motor is simply not getting enough voltage from the pump and valve controller. We know as of tonight that there is nothing wrong with the engine speed dial or the Control Console, as we swapped one from my 450CLC, so it looks like its definitely a faulty pump and valve controller. We opened that up today and found some slight corrosion inside, but generally nothing visible (even under a magnifying glass) that would indicate a faulty board, capacitor, etc. I am going to order a new PVC tomorrow, but at this stage I'm not sure if that will be the fix, so I wondered if anyone on here has had any similar problem like this. Any helpful suggestion would be greatly appreciated.
It doesnt look like you have calibrated the new EC motor. I'd try that before a PVC swap.
We've done the EC motor relearn procedure a number of times, and have tried switching the relearn switch in the opposite direction, which is what Nortrax in Ft Myers suggested I try, since sometimes the relearn switch could be installed backwards. I'm wondering if its something simple like the relearn switch? I would really kick myself if i bought a new $1800 PVC only to find out its a $10 switch. No matter what we do, the EC motor won't cycle at all, just groans very slightly when you turn the key on. The Deere test manual is practically useless because it tells you what the voltage reading should be at the EC motor for idle (2.5-2.7 volts) and fast idle, etc, but it doesn't tell you which wire to check. There are four wires going into the EC motor: One wire is showing over 25volts and another 13+volts and one seems to be dead and the last one is showing fluctuating voltage of less than .5 volts. We assume this is the wire that should show 2.5 volts, so something is wrong with the current thats being sent to the EC motor. We traced the wires back to the PVC and they are showing basically the same voltage readings there, so it's not the wiring harness between the PVC and the EC motor. So, it's looking like the problem is in either the PVC or the cab harness somewhere. If anyone knows which of the four wires we should be looking for the voltage reading on that would help also. Thanks.
Spoke to Nortrax again and they seem confident that it is the PVC, as that is what commands the EC motor to step up and down the RPM. So, I've ordered a new one and will report back on how that goes..
It was the Pump and Valve Controller. Changed that out, did the EC motor relearn and and everything's good. Took the old PVC apart and examined it under high magnification and can see that one of the little NEC transistors inside is burned. Googled the number and found it for sale for $4.99!!! imagine that? literally a $5 part shut us down or a week and a half! Will probably get the transistor and have someone fix the old PVC so I at least have a spare.