Dozer #1- CAT D6T S# WFH00364 The operator says the machine engine will slow just like pushing the decelerator, with caution lite. I couldn't get the machine to do this in the equipment yard of course, so I scrolled through the lower monitor menu and come up with what may be fault codes (EO281.2 & EO0198.2) Since I haven't been able to get the machine to replicate the problem here, it doesn't leave me much to check. Are these fault codes? Dozer #2- John Deere 750J S# 142760 Machine veers left when traveling in forward or reverse, but I can correct it with the steer lever. Once I release the steer lever, its back to veering left again. I suspect a speed sensor but this brings me to my current issue......the CMU will not stay on long enough for me to scroll through the fault menu. It flashes off and on but will not stay on. I have checked the wiring plug ins , and the fuse circuit. I may have a broken wire or faulty ground. Does anyone have a electrical schematic for this part of the machine? Any help would be appreciated! Jeff
E281.2 is a restricted steering hydraulic filter which triggers above 41 degrees C E198.2 is a low fuel pressure warning possible derate if configured sorry cant help with the deere Mark
Jeff, here is the 750J CMU schematic - see if this helps. If you think you have a bad speed sensor, unplug one of them from the track drive motors. The TCU will set a fault code, but it will also turn off the software that compensates for speeds. If the machine tracks straight, you know its a bad sensor or wiring. If it doesn't, you could have something going on in your pump or need to recalibrate the TCU.
Thanks to both you guys. I had to make a quick trip to Nebraska and will be getting back to both of these dozers tomorrow. I will post my findings!
UPDATE. The JD 750J ended up being a loose screw on the circuit board inside the CMU. It looked like the board was grounded through these mounting screws and all 4 screws had vibrated loose. Saved buying a $1500.00 CMU. The CAT D6T was a fuel filter restriction. They didn't mark their filters with dates or hours so the is no telling how long they have been on there. The filter change corrected the low fuel pressure warning and fuel derate. Both you guys get a GOLD STAR. Keep up the good work! Thanks ALOT, Jeff