John Deere 850K

[Tony Wells]

Got a new project today. Owner decided he doesn't need this machine in favor of the 700K he has. This one has been sitting a while, but started on its own after a few prelim checks. After a few minutes it overheated, so I didn't get to run it, but a couple of codes popped up.

SN 1T850KXPEE267161
~3900 hrs on it.

647.5 is Fan Speed Solenoid Open Circuit (related to temp problem I'm thinking)

111.18 is coolant level low (it isn't)

I was told (yeah, I know) that there was a transmission code, but it's not in Active Codes presently. I did not check stored codes yet. Might have one there. I'll be back on it Monday;

 

[mg2361]

Usually when there is a failure of that circuit the fan will default to high speed, which would make overheating unlikely. Fan proportional solenoid should measure approximately 27-30 ohms. If OK, then obviously a wiring issue. For the wiring issue, a short to power could trick the ECU into thinking there is an open, setting the DTC. That solenoid needs current (it is a PWM circuit) to slow the fan. Less current and the faster she'll spin.

With the ignition on and the engine off, there should not be any voltage to the solenoid. If there is, then there is a short to power somewhere.

 

[Tony Wells]

Thanks mg. So additionally, if that solenoid were mechanically stuck closed, even with good coil values it still would not drive the fan, correct?

Or if there was a hydraulic failure? Everything moves, so I’m not counting on that.

When I started it, it took maybe 10 mins to get to the Red Zone and indicate overheat. That’s where I stopped yesterday.

It’s good that I am getting this information over the weekend so I can look deeper Monday.

I’m about to leave and pull in 1200 feet of fiber optic cable at a hospital so won’t get back here for a while.

 

[mg2361]

When I started it, it took maybe 10 mins to get to the Red Zone and indicate overheat.

10 minutes is a bit quick. Make sure to confirm temperatures with a heat gun. Maybe a defective sensor.

A stuck solenoid valve could keep the fan slow, but it will not set a DTC in and of itself (except an overheat DTC when it reaches the set temp). With the 647.05 DTC, you have an electrical issue.

 

[Tony Wells]

Thanks mg... I'll have a busy Monday, but it's on my to-do list so I hope I can discover what's going on. I was told it had a transmission DTC, but I didn't get any active code for it. I'm guessing I'll gave to run it a bit to see it. Or I'll go back thru the stored codes. Either way I need to get it sorted.

 

[Tony Wells]

OK so here is where it gets weird. Typical for my stuff.

In no particular order:

Idle speed at 1200 RPM
Error msg: Blade Buttons - Stuck Button
Fan Speed Sol. Open Circuit (Note - Fan running full speed it seems)
Stored Codes:
VCU 522442.7
ECU 647.5
ECU 110.0
ECU 110.16
ECU 110.15
ECU 111.1
ECU 111.18

Odd pressure readings (to me) Right System 315 PSI/ Left System 450 PSI

I don't know for sure what the wind/thermometer icon means. Steady on, even after an hour. NO overheat today. Ran it about 2.5 hours.

 

[reganj]

I am probably wrong but the high idle and symbol to me mean it is in Regyn.
Some of the Smart Fellers will be along to correct me ifn I am incorrect, or, maybe I am actually right.

 

[Tony Wells]

I had that thought too, but it ran long enough to have completed a regen cycle, IMO.

Another oddity I forgot was the countdown to service is blank. Only displays dashes. I would think it would still show service due timing no matter what, even if it was reset in the past.

 

[mg2361]

It is in regen. It might not be completing due to the fan running full speed keeping the engine temperature too low. What is the engine temp? It has to be over 140*F for the regen to complete.

The 110 DTC's, if they become active, and if the temp is accurate, would also prevent a regen from completing. Again, test with an infrared temp gun.

Low coolant (111 DTC's) could also prevent the regen from completing. If the coolant recovery bottle is full, then you may have a defective switch.

As far as the pressures, ignore until the engine issues are resolved. One thing at a time.

 

[Tony Wells]

It's hovering around 185° F. That temp is accurate per IR gun. The jug is full of coolant. That code is not currently active.

The low coolant code, even stored, can it cause a failure? Seems more logical that it inhibit regen rather than not complete.

I'll run it again today.

 

[mg2361]

The low coolant code, even stored, can it cause a failure?

If it remains stored, it will not affect the regen.

 

[Tony Wells]

In the machine now. When first started, idle speed 900. Looking thru the service menus I noted that the soot load was “moderate”. I was shortly prompted to do a cleaning cycle. Prior to this, I was looking at the service interval timers and there are no values displayed on any of them.

So started a cleaning cycle and have a progress bar onscreen showing “PREPARING TO CLEAN”, with no progress showing after 30 minutes. The machine idled up again. I’m wondering now about an internal clock feature.
What determines how long the regen/cleaning will run?

 

[Tony Wells]

Ok that timed out incomplete. Exhaust filter shows high soot level now.

 

[mg2361]

Exhaust filter shows high soot level now.

Do you have any 3719.XX DTC's?

 

[Tony Wells]

No. I posted all the codes present, active and stored. No code changes since I started working on it.

This change in soot level reading came after about 30 mins of high idle while trying to do a parked cleaning.