Machine works fine in manual mode. No start under ECM. ECM pulses the throttle several times and then displays "electrical problem". Throttle jumps but returns to minimum on each pulse. Found a rabbit in the engine compartment and suspect wire damage but can't find anything between the throttle motor and the cab. I understand this machine is similar to case 9030b and link belt 2650 Quantum. I would like some help on extracting fault codes and locating a repair manual. Also. I replaced the batteries with sealed units and need some help disabling or fooling the battery fluid level warning.
Update- to check suspected throttle cable sticking when run by the computer I disconnected the cable. Same action. Wiring diagram shows a "throttle sensor" wire running from the throttle motor to the computer. Wondering if the computer returns throttle to minimum when it cannot sense throttle position. When running ok in manual if I switch to computer the throttle goes to minimum and engine dies. Sensor must be inside throttle motor housing and is not listed as a separate part.
Throttle problems are difficult to troubleshoot with the ECU, I have found that the wiring harness running to the cab has a plug under the battery box, If the throttle motor sensor pins short to each other the machine goes to full throttle and if they open the machine stays on low idle (found this out when a customer changed his own batteries and crushed the plug). I have also replaced a lot of stepping (throttle) motors on Case 90B's for throttle position sensors. I'll try to dig up my 90B training manual and find the direct test for the sensor circuit. Hope this helps
Well I found my old manuals on 90B's. When the key is turned on the throttle driver cycles the throttle motor to find the limit switches. The test for the limit switches is diconnect the throttle motor plug and the throttle cable on the side of the control link. Move the throttle motor clockwise, you should have contiuity between the white and blue wires at the plug. Move the throttle motor counterclockwise, you should have continuity between the green and blue wires. To extract the fault codes turn the key switch to the ON position and press the CHANGE switch once, press the PATTERN switch 2 times until CH:3 is shown on the message display. If 3 beeps are heard no electrical problems are found. if there are problems(no beeps) continue checking CH:3 by depressing the SELECT switch, this scrolls thru the different modes. The computer cannot detect a short of the RPM sensoe or Short or Open of the Throttle Volume (throttle limits) Hope this helps
Thanks. I think this means I could have an open on either the position sensor circuit or one of the limit switch circuits. I may try jumpers from the first throttle motor connector all the way back to the ECU input if the limit switches test good. Is the rpm sensor different from the throttle position sensor? I'm getting a new "electrical problem" message after the throttle module gives up and wondering if that indicates a bad position sensor or open circuit.
No problem, if the limit switches test good you should check the contiuity of the limit switch wires to the throttle driver. The driver is the small ECU located behind the main controller. On the 90B's the wires are #435(white/green)this is the green wire at the throttle motor. #436(light green/red)this is the blue wire at the throttle motor. #428(green/blue)the white wire at the throttle motor. Plug it in and run the same test as before but test at the square 12 pin plug at the cab (this harness has a colour band on it). Can you get to CH3 and retrive the fault codes? I should be able to help you there. Yes the rpm sensor is different. It is located on the bell housing.
I'm away from the machine for a couple days and will get back to you with the codes. My change, pattern etc buttons (four of them) under the cover are labeled in chinese. Not sure which is which, upper right, upper left etc
I can't read chinese as well LOL. The upper left is CHANGE. The upper right is PATTERN. The lower left is SELECT. The lower right is RESET. Hope the display is in english (juet in case I'll see if the language can be changed) Just let me know. Thanks
English on the display. But who knows if I ever have to reset? Be good to know how to change language. I'm watching e-bay for manuals.
Thanks,and by the way, is the rabbit stew ready?
Just a note, the Sumitomo,older JCB, Case and LinkBelt machines are all built by Sumitomo, but each used a different engine and I've found in the past that each had their own wiring harness. They were very similar but the wire colors are often different. Of the four, Case manuals are the best one to get, just remember that the wiring schematic will be a little bit different.
Good to know. I think the Sumitomo brand was sold in some English speaking countries, maybe Australia. But, so far, I have not turned up any English manuals
Lots of new info. Limit switches both ok. Closed at end of stroke otherwise open and not grounded on cab side of the connector. Link Belt wiring diagram shows circuit 450, throttle sensor, dead ending at the throttle motor connector. I have no wire into the throttle motor for the designated pin. Apparently throttle motor has no position sensor? No physical damage to cables up to cab entry. Key on gives mode S clock 0000. Link Belt says it should be 9 and 0000. Tried link belt reset instructions. With Reset in the msg box, holding reset button for 20 sec does nothing, no buzzer no change after key off. Clock apparently gives codes on key off. Reset=A120 EA1=0003 EAB RPM=nothing CH8=0000 CH7=0000 EAA1=0010 CH MN=A120 CH RPM=0003 CH FW MA=0000 CH FLS=0000 CH WS=0027 CH FS=0023 CH TV=0031 CH CS=nothing CH TR=0100 Tomorrow I will try to find the limit circuits at the cab as you suggested. Cannot get a CH3, just the options above. Cheers. Al
Forgot one. CHTR=0100.
The codes you have are for optional resets,EA1 and EAB are related to breaker engine speed, CH8 is your battery selection, CH TV is the throttle volume(dial for engine speed) etc. They are all in the self check mode. There is no "position" sensor in the throttle motor. If no codes are present you cannot get into CH3. Having 0000 showing on the display I think the throttle motor is "out of step",this happens if anything is adjusted on the engine side of the throttle motor. I have the Case automatic adjustment procedure if you want to try. We might have to be a bit inventive when you set up the machine model and manufactuer.
6 hours today. Found an open circuit and traced it to the square plug under the cab. Chewed off by rabbit. Soldered it up-added armor then had new problems. All the wires checked thu from the female side of the throttle motor plug to the driver plug. But I could not get a closed circuit at the driver plug for either limit switch. Finally decided it had to be an open limit switch ground in the throttle motor plug. Jumpered across the plug it and got it running but throttle acted strange. Found another open in the plug, soldered in a jumper and all is back to normal. I had been using a safety pin as probe in the female plug at the throttle motor and may have damaged it. I think the computer looks for the min limit switch to be closed, then open. My engine throttle stop is set so the high limit is never reached. I don't want to overspeed, but seems like the throttle motor is at risk if cable stops before the limit switch closes. I adjusted so the high switch closes but then the min limit does not close and computer will not run the throttle. No more 0000. Clock is working.
You got it! The first thing the ECU looks for is "0" at the limit switch. The link at the throttle motor should have an internal spring for high idle.
One last post with thanks. When the throttle motor pushes toward max the spring does not come into play. I reset my links so the high limit switch closes just before mechanical limit. On return to minimum or shut off, the spring lets the throttle motor pull past the mechanical limit and close the min limit switch. All works great and maybe saved a throttle motor problem for improper linkage adjustment.