850c II

[emarr]

Hi, i have a 850c II, and it wont move front or forward with joystick, but if i use manually the pcp valves on the front and back pump the ones under the cabin then the track move, if i use the pcp that are on each final drive they dont do anything, now what i do know is that somebody put 12v directly to does pcp valve on the final drives, what i have read is that does pcp may be damage because the only use a max of 5v, is there a way that i can test does pcp to see if they are damage?

 

[Diesel Dave]

Welcome to HEF emarr .
Serial number ?
Damaged motor PCP’s shouldn’t shut down the transmission.
Any service codes ?

 

[emarr]

Ok serial is T0850CX899052
F636
F437
F645

 

[Diesel Dave]

F645 is hydrostatic pump speed sensor wiring open circuit which is causing the transmission shutdown.
F636 is right and left motor speed sensor wiring short to ground
F437 is fuel temperature sensor/ circuit fault .
The link below has a hydrostatic pump speed sensor to transmission controller wiring schematic along with wiring diagnostic checks @mg2361
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JD 850c 2001 - Series II

Hello, As of writing this I will have to update with the serial # but the issue I am having is dozer will not move at all, throwing code F640. Thanks.

www.heavyequipmentforums.com

 

[emarr]

F645 is hydrostatic pump speed sensor wiring open circuit which is causing the transmission shutdown.
F636 is right and left motor speed sensor wiring short to ground
F437 is fuel temperature sensor/ circuit fault .
The link below has a hydrostatic pump speed sensor to transmission controller wiring schematic along with wiring diagnostic checks @mg2361
.

JD 850c 2001 - Series II

Hello, As of writing this I will have to update with the serial # but the issue I am having is dozer will not move at all, throwing code F640. Thanks.

www.heavyequipmentforums.com

Now i have F653 and F437 codes

 

[Diesel Dave]

F653 is for neutral start switch wiring open circuit .
F437 is fuel temperature sensor/ circuit fault.
.
FYI, the Transmission and Engine service code list is also in the Operators Manual .

 

[emarr]

How i can troubleshoot the F653 or were is located if any idea

 

[Diesel Dave]

https://partscatalog.deere.com/jdrc/sidebyside/equipment/67497/referrer/navigation/pgId/77024947 .
.

 

[emarr]

Hello, well now i manage to move, but is not movin like it supposed to, and the track speed switch does not let me go faster or lower, is in the lowest right now wish is one, when i try to move it goes all diferent direction but the one that im trying to go, and went go in reverse is reallly slow like no power at all

 

[Diesel Dave]

Any service codes ?

 

[emarr]

655

 

[Diesel Dave]

F655 , is for Neutral Start Switch Input Wire Short or Switch Short or Sensor Not Moved through Full Travel During Calibration .
The result is transmission operates at very slow (creep) speed.

 

[emarr]

Okok, o guess i will work on checking does wires tomorrow, thank

 

[emarr]

Hello, im back, now is running but is going left when turning right, can that be fix with calibration? No codes

 

[emarr]

Hello, the calibration manual indicates that put the rpm on 1500, but the lowest it goes is 2000, is that normal?

 

[mg2361]

the calibration manual indicates that put the rpm on 1500, but the lowest it goes is 2000, is that normal?

Nope. Need to get your rpm issue fixed before you can calibrate.

 

[emarr]

Ok, and what is the lowest that machine suposed to go on rpm?

 

[mg2361]

900

 

[emarr]

Is there a way to fix that?

 

[Diesel Dave]

Follow the throttle cable down to its end. You’ll find a linkage that actuates a throttle position sensor. If all the linkage looks in place and functioning , remove the sensor from the linkage.
With the sensor wire harness still connected , manually rotate the internal hub of the sensor and see if you are able to control the engine speed.

https://partscatalog.deere.com/jdrc/sidebyside/pin/T0850CX899052/equipment/388906/referrer/navigation/pgId/400830034

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