I'm working on a Deere 850K dozer, S/N 1T0850KXTFF290966. It will present active codes after operating for about 30 minutes, sometimes it will throw 1347.7 (high pressure fuel pump pressure control valve circuit fault) and sometimes it will throw 157.1 (rail pressure extremely low). I pulled those from the diagnostic menu on the machine. I have Service Advisor but I do not have the EDL to connect. Anyway, when I tried to look those codes up I cannot find them in SA, I looked under both serial number ranges and came up with nothing. Am I just not looking hard enough lol? Or does anybody have any ideas? I changed fuel filters when I got the low pressure code, but one code or the other still pops up after a little use. Any help would be greatly appreciated!
In Service advisor look for engine manual CTM120019
When you input a service code into the search box, it has to be in the full SPN/FMI form for Circus Advisor. So, 1347.7 should be typed in as 001347.07. Same with the other code: 000157.01. That will get you to the codes.
Yep, I knew it was something boneheaded on my part. I haven’t gone through all of the info yet, but without the EDL I’m sure diagnostics will be limited. I have Jpro as well and a nexiq edl but it doesn’t seem to offer much in live data. Low pressure side of system is fine so far as I can tell, I put the new filters on dry and the electric pump filled separator fast and it was easy to restart. Flow seems good up to high pressure pump. After filters, operator texted me a picture of 157.1 code. I operated the machine a few days later and got the 1347.1 code. It was way too muddy to push so I was just moving around the yard and operating blade when code presented. I’ll test wiring for sensor and relief back to ECM tomorrow. I have a relief valve on hand, but I hate to throw parts at it
Your issue is most likely the SCV. If you had the EDL, you should be able to see all the readings, particularly the actual/desired fuel rail pressure. With Service Advisor, you should have the ability to do anything I can do except program controllers.
10-4. I could be wrong but according to the parts diagram on Deere’s website it does not show an SCV. At least not the old cylindrical dude with two bolts holding it in. Rather this one seems to have flow controllers at the top of the pump and they don’t seem to be available separately from the pump
You are right, I stand corrected. Damn, that's twice in a week I got burned on an 850K HP pump assuming the 6068 had the SCV. Measure the low pressure fuel system with a gauge. Will the low pressure fuel system go into a negative value?
I'm not an expert on Deere 850K dozers, but it's possible that the codes you're seeing are not listed in the Service Advisor manual for your specific serial number range. You may need to consult with a John Deere dealer or a mechanic with expertise in this machine to get accurate information on the codes and possible solutions.
I’ll have to get fittings to plumb into fuel supply unless there is somewhere I can plug a compu-check fitting into. While monitoring fuel pressure in the service menu it seems to stay between 2-5 psi while at idle and at 2200 rpm, but I haven’t monitored it while operating. I’ll do that here shortly and report back. Thanks!
After operating for about half an hour it popped the SCV code again. And I use the term operate loosely lol, it’s been too wet to do anything but track around the yard while operating hydraulics. While I was “operating” the monitor showed fuel pressure at 1-5 psi and it hit 0 one time after 1347.7 code presented. Every time I’ve operated it popped the pcv code only so for sh*ts and giggles, I ohmed both pairs of pcv wires back to engine ecm as well as pressure sensor, all came back good.
I don't believe the pressure transducer on that fuel system shows negative values (I'm probably wrong on this one too ). If you could get a gauge in there that would be great. Need to confirm a negative or not. If it is in a negative value long enough, it will set mismatch codes.
10-4, I’ll get plumbed into it some kinda way and report back Monday morning
It's strange that the fuel pressure is fluctuating and the code is only appearing when you operate the hydraulics. Have you tried checking the engine ECM for any issues? It might be worth consulting with a mechanic to diagnose the problem
I didn’t get time to report back yesterday. I have not been able to find a fuel pressure gauge that will read vacuum, hell I may have to use a low pressure a/c gauge lol. I was messing with the machine yesterday and ran through the low pressure pump test. Apparently it’s supposed to produce at least 1 liter of fuel in a 60 second period. According to manual the pump will come on for 60 seconds when ignition turned on. On first test it did great, but every test thereafter it would barely produce .5L. I left ignition off for several minutes in between each test. I installed new low pressure pump this morning and had better pressure than ever, but it still threw the 1347.7 code after tracking around the yard for 10-15 minutes. This thing is giving me more grey hairs, but I do appreciate everyone’s help
If there is a restriction in the fuel system prior to the low pressure fuel pump, then it will still throw that code. Maybe something floating around in the tank blocking the pickup? A collapsing rubber fuel line?
Just an update, a friend of mine brought an EDL over and we monitored actual/desired while pushing. Rail pressure was about 5000 psi low and I finally got the 157.1 code that was in the history. I knew supply pressure was no longer an issue so I installed a high pressure pump and machine is good to go again
Great troubleshooting! Installing a high pressure pump resolved the issue.