Hi all, new member here. I have been looking around and I like the forum. I bought a ex120-2 recently and have been working on fixing all the issues. The wiring harness had been butchered all over the place so I put in a new internal and external harness. After plugging everything in the stepper motor only buzzes/vibrates whenever one of the throttle buttons is pushed. When the key is on, engine off the "I" light comes on and then moves to the "P" position after a couple of seconds but the motor does not move, try to move, or buzz. Moving from "I" to "P" with the engine off is part of the throttle calibration procedure during start up right? When I start pushing the throttle buttons (engine still off) I can hear the throttle motor buzz. There is a short buzz between each button push if I push them in order I,L,E,P. A longer buzz is heard if I go from "I" to "P" so it sounds like proper signals are being sent to the motor. I just installed a new stepper motor today and nothing changed, still makes buzzing noises but does not move. With the key on the motor holds the throttle cable in place and I can hear the motor humming. When the key is turned off the cable can be moved by hand. I have tried disconnecting the cable so the motor can move more freely but it still does the same thing. With the old stepper motor I actually unbolted it from the gearbox so I could see the small pinion gear and it reacted the same. Any ideas are appreciated. Hopefully I didn't miss an old thread that has an answer for this.
Welcome to HEF Jason ! Did you wait 10 seconds before keying off after pressing the "P" for calibration? Was the voltages checked for the EC motor to make sure it was adjusted correctly?
Hi mg2361, thanks for the reply. I have not pressed the "P" for calibration at all. When I key on l look at the lights and it starts in "I" and then moves to "P" all by itself. After that I have pushed buttons and get the buzzing noises from the ec motor. When checking the voltage for the ec motor, do you mean the ec senor? I have adjusted the ec sensor so that it is in the middle of it's range on the slotted holes and when back probed it reads 2.2 volts. I have the technical manual and workshop manual for the machine but it is kinda vague on the specifics of setting up a new ec motor. The technical manual talks about moving the t-link to the end of it's clockwise rotation, etc. It didn't say anything about waiting 10 seconds. I'm a little confused.
With the engine at idle, the voltage has to be 2.5-2.6 volts. Also inspect the mechanical linkage for wear, especially the spring (see below). I PM'd you.
I have had that spring apart completely and nothing was broken inside. The spring was loose inside when I got the machine though, so after putting it back together I tightened one nut against the the spring by holding the shaft and then installed the small ball joint. Now when I get the motor to work properly it should be pulling against the spring right away. Is it more complicated than that?
Progress report, I tried solution 77684 (thanks mg2361) which is to be done if the ec motor does not move and no noises can be heard or if it is making a growling sound when buttons are pushed. Step 1: Key off, disconnect ec motor, key on, check that 1 or 2 of the ec motor harness wires have 24V while gounding the multimeter to the chassis. I got 23.5V on the orange wire and 23.9V on the yellow wire. Step 2: If step 1 was good, key off, reconnect ec motor, key on, back probe each of the 4 wires while grounding to chassis. Brown and Orange controls one coil and red and yellow control the other on the ec motor. There should be ~9V differance between the readings of the pairs. Brown 23.56V Orange 23.57V So no difference on that side of the motor Yellow 10.79V Red 2.14V 8.65V Difference on the other side of the motor If any pair has 24V on both wires then the circuit is not complete. Check the wiring. I did that and the wiring was good since I just replaced it. If the wiring is good then replace the EC controller. I took the top off the computer and found a large computer chip marked SS2B003. Did a little google search and this is the "driver" for the ec motor. Friday Parts sells them. I received it the other day and soldered it into the circuit board. The ec motor now moves when buttons are pushed, hooraaayy. Now the bad news. I have tried the relearn procedure a couple of times but it does not seem to work. It's quite simple, key on engine off, push "P" button, wait 10 seconds for ec motor to move leaver to full power set screw, then key off and the procedure is complete. When I try it the ec motor move a little but not to the full power stop. - key on and the lights move from I to P but the motor does not move. - if I start playing with the buttons, I L E P, the ec motor will start moving the govenor lever, but the lever will never be in the same position twice, meaning when I push E button for example and then the others and come back to the E button, the lever is not in the same position as when I had pushed the E button the first time. - when I turn the engine off the lever is moved towards a higher power level, weird. Instead of going to towards idle. If I then go to start it the govenor lever will still be in that high position unless I first push the I button and then start it. -I have put the bolt throguh the t-link and set the ec senor to 2.5V when the lever is in the idle position. When the lever is in the full power position the ec sensor say 3.8V Any help is appreciated. If anybody wants a better explanation of something let me know.
This usually occurs due to adjustment issues or linkage issues. Did you run through the voltage checks again to check if they are what they are supposed to be?
Ok, I did the voltage checks again and got good results Connector unplugged: Orange wire 23.9V Yellow wire 23.9V Connector plugged in: Brown 11.3V Orange 2.0V Difference 9.3V Yellow 11.5V Red 2.1V Difference 9.4V I took the whole ec motor unit off the machine so I could have a look at the linkages again. Everything was tight but when I grabbed the t-link and tried to move it, it was really stiff. I put more pressure on it and then it moved. It had a notchy/grabby feeling. I disconnected the torque damper and just tried to move the lever on the end of the gearbox shaft. The nocthiness was definitely coming from the new stepper motor unit I put on a little while ago. I removed it and put my old ec motor/gearbox back on. I had taken this one apart and re greased the whole thing. It moves freely. With the old ec motor installed the governor lever will actually return to idle position all by itself now when the key is turned off. When I go to try the relearn procedure, I turn the key on and then try to hit the power button before the little led jumps from I to P all by itself. It usually takes a couple of seconds for it to do that. It doesn't seem to matter if I push the P button before or after the led moves from I to P, when I push the P button the governor lever only moves maybe a quarter inch of the idle stop and makes no attempt to go all the way to the full power stop. I did order the MPDr. Software from Sinocmp. It came with a CD and a cable. I followed their instructions to install the program on my laptop and it seemed quite easy. When I went to run the program a little window popped up with an error code. I tried running in compatibility mode and as administrator but nothing worked. I contacted Sinocmp and they directed my to their technical guy. I sent him multiple emails with screen shots of the error codes and he never got back to me. Kinda annoying how they are ignoring me after I bought they complete interior and exterior wiring harness from them. Do you know how to get MPDr. running mg2361? It would probably help quite a bit to know what the computer is seeing from the sensors. I feel like I am stumbling around in the dark lol.
I'll try. Are you only getting one error or are they different? Post a picture of the error/errors. Those machines are challenging even with a working MPDr. I'm working on one now (Deere490E which is an EX120-2). After reading your latest post and going back through, you're saying the engine speed LED changes by itself from I to P without touching the buttons?
I PM'd you.
Hey folks know this might be a old thread , can anyone tell me the correct procedure for the learn sequence , is it key on hold p for 10 seconds release p leave off for 10 seconds ?
The procedure that I have from John Deere is as follows: (ex120-2 and JD 490E is the same minus the engine) 1- remove any diagnostic cables from the 4 pin connector 2- turn key to on but do not start 3- press "P" button for the automatic calibration. Wait 10 seconds for the ec motor to move to the high idle stop on the injection pump (full power) 4- Turn key to off 5- Check the full power engine rpm with a scan tool or a non-contact tachometer. Compare to the manual and make any adjustments. Hope that helps Jason
The procedure is not 100% clear. Just press and release the button, wait 10 seconds. Then key off.
Thanks for the simplification mg2361. I was looking at the procedure and trying to simplify it because the original is worded kinda weird, but I may have made it worse lol!