I have a 690E-LC. When i start it up first thing in the mourning everything runs right 10mins maybe. Then the machine will drop idle maybe 100 rpms lower then normal and i cannot change power output. Machine will not adjust engine speed to hydraulics's on the Switch panel 2. it you let it sit for a few hours then everything will work right again for a couple minutes maybe. This was a problem we faced this spring and we went through checked every wire, fuel actuator solenoid, Speed sensor, stand by relay, Checked all the pins and cleaned everything plug. We have a service manual i have i checked and tested every wire, relay that it goes through in the book and could not find anything wrong . Deere mechanic come down he replaced the Switch panel 2. Made no difference. Already replaced both system controller and switch panel 2 four years ago and then it was the system controller. i found a burnt spot on the circuit board then. The symptoms then were similar but it quit working all together, Not like this were it works then it doesn't. I opened this system controller and everything looks fine nothing burnt. We started using it again yesterday first time since spring. First day we started it up, ran perfect for 10 hours, Next day about 3 hours. I come to believe it is something that is getting hot and then it does not let the System controller send the signals to the switch panel 2. When this happens on the Switch panel 2, The travel speed Light changes when i press the button. Mode button changes, Auto ilde light changes, But Swing brake light will not change and The 4 power buttons will not change. I can tell if the machine is going to work properly by just turning the key on without starting it. I was thinking it had something to do with the Ground G50 but when the machine has the problem they system controller is still lit up. If i go through the Diagnostics it cycles through the lights but the machine does not do rev up or change engine speed. I believe once something starts getting hot and then the system controller losses communication with the Switch panel 2. i am looking for any direction to go with this. Already Dropped 3k between new switch panel 2 and Service call. And i know if i call the tech again he's going to tell me System controller which is another 3k. I really don't believe it the controller yet. i think i have a wire or Relay or something getting hot. Any help would be much appreciated.
Welcome to HEF PWC ! First a serial number please. Do the hydraulics stall the engine when the issue is happening? When the issue happens which specific mode light does it switch to (I, E, L or P), if it switches? Answers to these questions might help lead us in a direction (I hope ). Double check your G50 ground all the way back to the battery. Perform a wiggle test on the harness to make sure you never loose continuity. Also double check your K18 Standby Relay. I know you said it was checked but was it swapped with another for testing?
PIN #DW690EL537343. Yes, when it is not working correctly hydraulics stall the engine. On G50 Ground, I checked continuity on wire #103 out of the bottom plug on the system controller. Continuity was there. If The G50 was the issue would diagnostic lights work on the system controller whenever the machine was having issues. I Swapped out Standby Relay with a different one. I will go in and test the Stand By relay to make sure. Is it possible for a Relay to work correctly and once it has a load on it, builds heat and Quits working?. Or would a relay act like a fuse in a sense. It either works or doesn't ? i will check continuity and wiggle the harness all the way back to the battery to check G50 again. When it happens the light stays on (L) and won't change when the button is pressed. But normally the machine Idles at maybe 900 rpms and when this happens the machine sounds like it's at 700 rpms. Not enough to excite the alternator from start up if it's working incorrectly from the start.
Based on your information check the speed sensor circuit (wiring and the sensor). If the speed sensor signal is lost then the engine will go to idle, mode will be "L", and the hydraulics will stall the machine. And to answer the temperature question, yes temperature can affect that speed sensor. Might want to remove it and inspect the end to see if there is excessive debris stuck to it also. Check the adjustment. The proper adjustment for that sensor is in until it touches the flywheel, then back out 3/4 turn. Sorry I don't have any resistance specs for that sensor. You could check it if you have frequency on your meter. While I don't have that spec either you want to see a steady reading. If it is all over the place then there is an issue.
Thanks, Speed sensor is where i started, I went through the book and checked the wires and the sensor itself and it checked out fine. I replaced the speed sensor anyways and it still did not change anything. I have a new Stand by relay coming. I'm going to put that in today and see if that changes anything. i have not had time yet to do more in depth checking on the G50. i'm hoping to get time later this after noon it get back on this.
Hello, were you ever able to resolve your issue?
I just purchased a John Deere 690DLC Excavator that has a similar issue to what the original poster described. It works useable with the computer control bypass switch on. When in computer control mode it will work properly for a few minutes before idling down to low idle and engine speed control unresponsive. If I push the I mode button, the hydraulics work about like they should for being in idle. The three other modes have little to no hydraulics at all. When I run the computer's self diagnostic, I test and adjust the low Idle speed, then when I go to adjust the high idle speed, it idles down and becomes unresponsive again after a minute or two. Reading the forums here I suspected the engine speed sensor. It tests good according to the technical manual as far as ohms go anyway. Next I tested the engine speed control actuator solenoid. The tech manual says it should read 26 ohms, my meter reads 6 ohms. I'm thinking that this solenoid is failing as when it throttles up, more power is fed to the solenoid, it gets hot and weak and stops working. Sounds like a great place to start replacing parts, except John Deere and everyone else wants over $1200 for this little thing. It's hard to spend that when I'm not 100% sure that'll be the thing that fixes it. I did order a similar solenoid that should fit dimensionally. It has the same throw, size, bolt pattern, voltage, only difference I can spot is the mating surface lacks the o-ring groove of the original. I'm betting I can make it work. Any thoughts or comments? The excavator's serial no is 565900 btw -SM
Welcome to HEF S.Moore ! Next time start a new thread instead of piggy backing an old one. What tech manual are you using? TM1387? Which procedure are you using in the manual?
Sorry about piggybacking, the original thread was never resolved here and my issue seems very similar. I will start a new thread now.
To answer your question about, controller lights on if G50 black ground wire has a problem. Yes, they will be on. I had a 690eLC with similar issues the customer had replaced batteries and the problem started after that. Run ok on start up than started lugging engine especially arm in and boom up. After looking at wiring diagram saw where G50 went to negative battery terminal, customer had stated problem started after battery replacement so i checked no G50 wire had to remove batteries to find it. I am trying to go by memory but i believe G50 wire in cab goes under a bolt that holds the controller in place. Someone else on the forum may be able to verify this may also depend on SR# break. Note also the hydraulics got really slow after a very short time running i would assume as the controller needed more current to operate the bad ground started showing up.