I have a 96 cat 315L i have had some issues with since i bought it. First of all the machine wasn't digging properly the stick in and out under a hard load would drag the RPMS down to the point it would stall the machine. I started investigating and found a group of wire below the engine that were broken also a short grounding wire that goes from frame to side of motor was also broken. I repaired all wires and hooked them back to ground, 5 wires in total. I checked the Cat parts online SIS and to the best of my knowledge all 5 black wires went to ground. Started the machine everything seemed good auto idle worked at first. Then auto idle stopped working and the rpms would just hang wide open until you turn the dial back to 1. Numbers on the screen go up and down. Is this a engine speed sensor issue? i did have it out and cleaned it maybe i put it back in wrong not in far enough? Pretty sure the other issue with the pump not destroking is fixed i will have to run it more to find out but just running it in the driveway it felt alot better. Any help would be appreciated.
Post a Serial Number and you can have an Electrical Schematic.
Serial number is 6ym00484
That machine has a diagnostics menu accessible from the monitor panel. The link below goes to a video that shows you how to get to it. It's been a long time and I don't recall which menu takes you through the codes but someone should be along to guide you though the final steps. Good Luck!
Hi, With your explanation it seems like your rpm sensor signal does not come to the controller. Auto idle process to happen as intended, several things should be working correctly those are 1.AEC switch should be on . 2.Rpm sensor signal should come to the controller. 3.Good implement & travel pressure switch.(input to the controller) 4.Governor actuator motor should be working according to the controller signal.[that means governor actuator should work when you rotate the speed dial knob (if the speed dial signal reach to the controller correctly)] And your engine speed dial back up switch should be in auto position. So if your governor actuator motor or rpm sensor not working properly auto idling does not work. And when working with implements if your engine stalls against load then one cause of it is ,your pump is not destroking properly through prv solenoid. This process to happen correctly rpm sensor signal should reach the controller properly. If not engine is going to stall under the load. So rpm sensor is there for both issues. Thats why i guess that rpm sensor signal is not arriving in to the controller. Does the governor actuator work according to the speed dial knob rotation ?
I got the Auto idle issues taken care of. Turned out to be broken wires at ground underneath engine. Also engine speed sensor was dirty and someone may have had it out and put it back in with the wrong clearance to flywheel. My only issue now is the machine stalls under load only while lifting main boom all the way until it deadheads or while using full power while digging, Also can stall machine out using stick in or out same scenario. All other functions can be done and the pump destrokes properly to maintain engine speed. Is this a PRV issue? Or is this an issue with a pressure switch on valvebody infront of the engine compartment?
Hi, If auto idling works that means your implement pressure switch works. And speed sensor also working. Check whether your boom pressure switch woks or not. It can be checked by disconnecting the boom pressure sw connector and use multimeter to check the continuity of the pressure sw while operating boom handling liver up to the full raise position. When you operate boom handling lever to the full raise position continuity should exist. This can be checked via digital input test also if you know how to use the machine's data mode through monitor. But as you mentioned that engine stalls for arm in and out also, may be boom pressure sw will not be the problem. But it is worth to check it. Enter the machine's data mode according to the john c sir's video and after entering, at first you will see power shift pressure and display will show something like this (P 21 or another number) and at this time power mode 3 indicator bulbe will flash. Now press alarm cancel button and by holding it press the power button once. Now power mode 2 indicator bulbe will flash. Now you can see the engine rpm on monitor. You can multiply the number that displys by ten to obtaine actual rpm value. Now turn the speed dial knob step by step to see that rpm signal shows correctly on monitor. And perform a work untill engine stalls and see the rpm reading. Some times if the rpm sensor not adjusted properly rpm signal will lost at some point. And if that happens engine will stall under load. If the rpm sensor and boom pressure sw both works properly some times there may be an issue with prv. You can check these and will see what to do next. Hope that this will be helpful.