section 35 chapter 9 · 2010. 7. 1. · hitch controller. diagnostic and programming information...

Section 35

Chapter 9

6-12820NH

HITCH SYSTEM

How it Works

SECTION 35 - HITCH SYSTEM - CHAPTER 9

35-2

TABLE OF CONTENTS

THREE POINT HITCH ....................................................................................................................................... 35-3

ELECTRONIC HITCH CONTROL ...................................................................................................................... 35-4

ELECTRONIC HITCH CONTROL ...................................................................................................................... 35-5

ELECTRONIC HITCH CONTROL SYSTEM FEATURES .................................................................................. 35-7

HITCH CONTROL VALVE ............................................................................................................................... 35-14General ......................................................................................................................................................... 35-14Raise and Lower Solenoids .......................................................................................................................... 35-14Raise and Lower Pilot Spools ....................................................................................................................... 35-14Raise Spool ................................................................................................................................................... 35-14Lower Poppet ................................................................................................................................................ 35-14Load Check Ball ............................................................................................................................................ 35-14Manual Raise or Lower Control Pins ............................................................................................................ 35-14Overload Relief Valve ................................................................................................................................... 35-14

HITCH CONTROL VALVE ............................................................................................................................... 35-16Neutral Function and Troubleshooting .......................................................................................................... 35-16Raise Function and Troubleshooting ............................................................................................................ 35-18Lower Function and Troubleshooting ............................................................................................................ 35-20

SETUP / ADJUSTMENT SEQUENCE ............................................................................................................. 35-22


35-3

THREE POINT HITCH

GENERAL DESCRIPTION - The Three Point Hitchconsists of the rockshaft supports, rockshaft, upperlink, lift links, draft arms and the external lift cylinders.

The hitch conforms to ASAE standard dimensions fora Category III/IIIN hitch. The hitch is controlled withan electronic hitch system which provides positioncontrol of soil engaging implements. The hitch willaccept all mounted implements conforming to SAE,ASAE standard dimensions for Category III/IIIN.

A hitch coupler can be used with the three point hitchto quickly connect and disconnect implements. Seethe operator manual for proper hitch preparation.

The single acting hydraulic cylinders are mountedexternally and are supplied from the hitch controlvalve. The hitch control valve is mounted on the lefthand side of remote valve stack (rear/top of thetransmission).

The electro-hydraulic control valve is supplied fromthe PFC hydraulic system and the regulated system.The regulated supply is used to operate the valveand the PFC supply provides the high pressure flowto extend the cylinders and raise the hitch. To lowerthe hitch regulated pressure is used to operate thevalve to lower the hitch without activating the PFCsystem. Two electr ica l solenoids control theregulated oil supply to the valve, one to control theraise and one to control hitch lower.

The Electronic Hitch Controller supplies current tothe raise or lower solenoids based on commandsfrom the operator and measurement signals from thehitch and other tractor systems.

RP98G006

2

1

3

2

4

5 5

1. UPPER LINK 4. ROCKSHAFT ASSEMBLY2. LIFT LINKS 5. EXTERNAL LIFT CYLINDERS3. DRAFT ARMS


35-4

ELECTRONIC HITCH CONTROL

GENERAL DESCRIPTION - The Electronic HitchControl (EHC) system consists of the operatorcontrols, electronic hitch controller, hitch positionsensor, hitch control valve and the wiring harness.

All operator commands except Remote Up/Downcommands are sent to the Arm Rest Control Unitthen relayed to the Hitch controller by way of theData Bus. The Remote Up/Down commands aresent to the EHC controller direct as well as theRockshaft Position Sensor signals. Wheel speed andoptional True Ground speed signals are sent to theInstrument Cluster Unit (ICU) then relayed to theHitch controller. Diagnostic and programminginformation are communicated between the EHCcontroller and the Instrument Control Unit (ICU) byway of the Data Bus.

OPERATING MODES - The EHC system operates inthree modes based on operator commands andmeasurement signals from the hitch and othersystems.

1. Position Control

2. Load Control

3. Slip Control (Optional with True Ground Speed)

END-OF-ROW FEATURE - The EHC wil l alsoengage and disengage the differential lock and theMFD (When equipped) when the hitch is raised at theend of the row to facilitate turning and re-engagewhen the hitch is lowered.


35-5

RH

98F

144

EL

EC

TR

ON

IC H

ITC

H C

ON

TR

OL


35-6


POSITION CONTROL - In the Position Control Modethe hitch position and movement is directly related tothe position of the control lever. The EHC monitorsthe position of the hitch by signals received from ahitch position sensor on the hitch rockshaft andraises or lowers the hitch to match the signal from thehitch position control lever sensor. The hitch willalways raise at maximum speed to a height set bythe operator with the upper limit control. Duringlowering, the hitch moves at the speed selected bythe Drop Speed Control to a position set by theoperator with the Position Control. The operator canoverride the Drop Rate setting when lowering thehitch by activating the Up/Down switch to the downmomentary position 2 times within 2 seconds andholding it in the momentary position. The hitch willlower at maximum rate. In this case the hitch willlower to the lowest possible position, even if this isbelow the position command.

LOAD CONTROL - In the Load Control Mode theEHC maintains a constant draft load on the tractorsthree point hitch in changing soil conditions. When anincrease in load is sensed by the lower link draft pinsthe EHC will raise the hitch until the load matches theload set by the operator with the Load Control. With adecrease in load the EHC will lower the hitch to adepth the operator has set with the Position Control.

SLIP LIMIT CONTROL - The slip limit control modeis available when the tractor is equipped with TrueGround Speed (Radar) attachment. The InstrumentCluster Unit receives measurement signals from theTrue Ground Speed unit and the Wheel Speedsensor to determine the actual slip percentage. Thepercent of slippage is relayed to the EHC by way ofthe Data Bus. The operator can set a desired sliplimit range between 5 and 40% which the EHCcompares to the actual slippage signal from theInstrument Cluster Unit and raises the hitch when theslip limit is exceeded. When the actual slip no longerexceeds the slip limit, the hitch will lower to theposition command setting. The tractor must betravelling above 2 mph before the EHC will enter sliplimit.


35-7

ELECTRONIC HITCH CONTROL SYSTEM FEATURES

HITCH POSITION CONTROL LEVER - The PositionControl Lever (2) is used to raise and lowerimplements, and select the maximum working depthof the implement. To lift an implement with the threepoint hitch the Position Control Lever (2) is rotatedforward (clockwise).

To lower an implement, rotate the lever rearward(Counterclockwise). The Lower Limit Stop (3) can beadjusted to provide a lever stop which will enable thePosition Control Lever to return to the same setposition and set the maximum implement depth.

The Transport Lock (5) is a detent device moldedinto the arm rest control console. The PositionControl Lever can be locked in the raise position toprevent the lowering of raised implements duringtransport. This can be done by pushing the PositionControl Lever all the way forward (clockwise) andsnapping it into the detent position. As an addedprecaution the Up/Down Switch should also be in theUP position.

UP/DOWN SWITCH - The Up/Down Switch (1) is athree position switch used to raise and lower thehitch without changing any of the hitch adjustments.The three positions of the switch are: UP; DOWN(Middle) and MOMENTARY (Full forward).

When the switch is put in the UP position the hitchwill raise at maximum speed to the position set by theUpper Limit Control.

When the switch is put in the DOWN position thehitch will lower to the limit set by the Position ControlLever at the speed set by the Drop Speed Control.

When the switch is pushed into the MOMENTARYposition and released, pushed again and held (Within2 seconds), the hitch will lower to the lowest possibleposition at maximum speed (Bypassing the DropRate Speed setting and position control lever).

The switch can also be used to raise and lower thehitch at a timed momentary rate in case a systemmalfunct ion creates a “Limp Mode” condition(E lec t ron ic sys tem no t func t ion ing ) . TheMOMENTARY posit ion wil l al low a timed (1.5seconds) lowering of the hitch when in the “LimpMode”. When the hitch is in the “Limp Mode” togglingthe switch between the UP and DOWN positions willallow a timed raise (1.5 seconds) of the hitch.

HITCH LOAD CONTROL - The hitch load controlknob (10) sets the depth of the implement to controlthe load on the tractor. Turn the knob clockwise toincrease the load on the tractor by lowering theimplement. Turn the knob counterclockwise todecrease the load on the tractor by raising theimplement.


35-8


RH02G120 AND RH01K052

1

2

3

8

4

5

6

7

9

10

1. UP/ DOWN SWITCH 6. SLIP LIMIT CONTROL SWITCH2. HITCH POSITION CONTROL LEVER 7. UPPER LIMIT CONTROL3. LOWER LIMIT STOP 8. DROP SPEED CONTROL4. LOWER LIMIT LOCK 9. TRAVEL CONTROL5. TRANSPORT LOCK 10. HITCH LOAD CONTROL


35-9


UPPER LIMIT CONTROL - The Upper Limit Control(7) limits the amount of upward travel when the hitchis raised. The control knob is mounted under the armrest cover on the arm rest control console and hasnumber settings from “1” to “11”. Turning the knobcounterclockwise limits the upward travel of the hitchand turning clockwise allows the hitch to raisefurther. A setting of “11” will allow the hitch to raise tothe “Full Up” position. A setting of “1” will allow thehitch to raise to approximately 50% of full travel. TheUPPER LIMIT CONTROL allows the operator totailor the upward hitch travel to specific implementsor mounted PTO implements.

DROP SPEED CONTROL - The Drop Speed Control(8) limits the hitch lowering speed. The control islocated under the arm rest control cover on the armres t cont ro l conso le. Tur n ing the knobcounterclockwise causes the hitch to lower slower.The Drop Speed should be adjusted slower forspecific implements such as planters, to preventseed tube plugging. A faster speed would be used forplows and rippers.

REMOTE UP/DOWN SWITCHES - The REMOTEUP/DOWN SWITCHES are located on the rear of thetractor mounted next to the implement electricaloutlet. The switches are used to operate the hitchmomentarily from outside the cab to make small slowmovemen ts to the h i tch to a id i n a t tach ingimplements to the hitch. The switches will only beactive if the tractor is not moving. The hitch cannot beraised above the upper limit. After the hitch is movedwith the remote switches it may be necessary therecapture the hitch with the Position Control Leverwhen the operator returns to normal operation.

LOAD CONTROL - The LOAD CONTROL KNOB(10) is located on the arm rest control console and isused to set draft load on the three point hitch. TheEHC receives a load signal from the lower link draftpins and adjusts the depth of implement to match thedraft load signal set by the operator with the LOADCONTROL KNOB. The tractor must be moving 0.5mph or faster before the Load Control Mode willactivate. Turning the LOAD CONTROL KNOBc lockw ise w i l l i nc rease the load andcounterclockwise will decrease the load. LoadControl Mode wil l be shut off when the LOADCONTROL KNOB is turned to position “11”.


35-10



8

9

1

2

3 4

5

6

10

7

1. UP/ DOWN SWITCH 6. SLIP LIMIT CONTROL SWITCH2. HITCH POSITION CONTROL LEVER 7. UPPER LIMIT CONTROL3. LOWER LIMIT STOP 8. DROP SPEED CONTROL4. LOWER LIMIT LOCK 9. TRAVEL CONTROL5. TRANSPORT LOCK 10. HITCH LOAD CONTROL


35-11


TRAVEL CONTROL KNOB - The TRAVELCONTROL KNOB (9) is located under the arm restcontrol console cover. Travel Control varies therange of hitch corrections in response to loadvariations when operating in the LOAD CONTROLMODE. Turning the TRAVEL CONTROL clockwiseto a higher setting will result in larger amounts ofhitch movement in response to a load change and acloser control of the load when operating on unevente r ra in . Tu r n ing the TRAVEL CONTROLcounterclockwise will result in less hitch movement inresponse to a load change and increase thevariations in load which would be used in levelground conditions.

SLIP LIMIT CONTROL SWITCH - The SLIP LIMITCONTROL SWITCH (6) (If equipped) is located onthe arm rest control console and is used to engage ordisengage slip control and set the desired slip limit.The slip control rocker switch has three positions:

1. OFF - Symbol (O) this position is used to turnSLIP CONTROL OFF and it is also used todecrease the slip limit setting.

2. ON - Symbol (I) in this position, the system willoperate in the Slip Limit Control Mode. If no limithas been set the system will default to 30%.

3. SET (Momentary) This position is used to set theslip limit.

To set the SLIP LIMIT the tractor must be properlyballasted for the load being pulled and moving over 2MPH with the hitch set for the desired implementload or position. Move the Slip Limit Control Switch tothe “ON” (middle) position, then press the “SET”(momentary) and release. The performance monitorscreen on the Instrument Cluster will display. Thetriangle indicator under the bar graph will indicate sliplimit value, which will be the current slip + 5%. Thesystem will not set below 5% or above 40%. TheEHC will raise the hitch if wheel slip exceeds the limitvalue.

The SLIP LIMIT can be changed three ways to matchfield conditions:

1. Reset system - Move the switch to the OFFposition for at least two seconds then reset bymoving the switch to ON then to SET andrelease.

2. Manually Increase Set Point - Press the switch tothe SET position and release. Each time theswitch is pressed the Slip Limit Setting willincrease 1%.

3. Manually Decrease Set Point - Move the switchto the OFF position then back to the ON positionquickly (one second or less) the Slip Limit Settingwill be decreased 1% each time the switch iscycled.

NOTE: The slip limit control switch is not functionalunless the tractor is moving faster than 2 mph.


35-12



8

7

9

1

2

3 4

5

6

10

1. UP/ DOWN SWITCH 7. UPPER LIMIT CONTROL2. HITCH POSITION CONTROL LEVER 8. DROP SPEED CONTROL3. LOWER LIMIT STOP 9. TRAVEL CONTROL4. LOWER LIMIT LOCK 10. HITCH LOAD CONTROL5. TRANSPORT LOCK 11. MFD SWITCH6. SLIP LIMIT CONTROL SWITCH 12. DIFFERENTIAL LOCK SWITCH


35-13

EHC SYSTEM FEATURES

END OF ROW FUNCTION - The END OF ROWfeature involves the Differential Lock and theMechanical Front Drive (MFD) (if equipped) and theBrake Switches. The MFD and Diff Lock controlsystems are equipped with an automatic function thatdisengages both Diff Lock and MFD when the hitch israised for a turn around and re-engages them whenthe hitch is lowered after the turn.

DIFFERENTIAL LOCK SWITCH - The DifferentialLock Switch (12) has three positions;

1. SET (differential symbol) - Push full forward(Momentary) to engage Differential Lock in themanual mode.

2. Center Position - Latch position for manual modeand Reset position for Automatic mode.

3. Automatic (A) - Provides automatic operation.

MFD SWITCH - The MFD Switch (11) has threepositions;

1. ON - (MFD symbol)

2. AUTOMATIC - (A)

3. OFF - (O) ISO Symbol

AUTOMATIC MODE FUNCTION - When the MFDand Diff Lock are in the automatic mode and the hitchis raised to the upper third of travel they wil ldisengage and reengage when the hitch is loweredbelow the upper third of travel.

The automatic mode of operation of the MFD alsoprovides these additional features:

The MFD will disengage when:

A. Travel speed exceeds 10 MPH

B. One brake is applied

The MFD will engage or reengage when:

A. One brake is released

B. Both brakes are applied

C. Wheel Slip exceeds 10% (If equipped withRadar)

D. Travel speed drops below 8 MPH aftertravel above 10 MPH

E. Differential Lock is applied

The automatic mode of operation of the Diff Lockalso provides these additional features:

The Diff Lock will disengage when:

A. Travel speed exceeds 10 MPH

B. One or both brakes are applied and held on

The Diff Lock will engage or reengage:

A. One or Both brakes are released

B. Wheel Slip exceeds 10% (If equipped withRadar)


35-14

HITCH CONTROL VALVE

GeneralThe hitch control valve is a closed center valve thatreceives oil from the PFC hydraulic system. Tocontrol the pump during hitch operations signalpressure is sent from the valve to the PFC pump.The raise and lower functions of the valve areoperated by regulated pressure received from theregulated hydraulic system. The valve is mounted inthe remote valve stack and consists of the followingcomponents:

Raise and Lower SolenoidsThe raise and lower solenoids (1 and 2), whenenergized by the Electronic Hitch Controller, willmove the raise and lower pilot spools (3 and 4)inward through contact with the control pins (14).

Raise and Lower Pilot SpoolsThe raise and lower pilot spools (3 and 4) control theamount of regulated oil pressure allowed to pass thespool lands to operate the raise spool (5) and lowercontrol piston (7).

Raise Spool The raise spool (5) is held in position by a springwhich blocks the flow of oil from the PFC pump.Regulated pressure from the raise pilot spool (3) willmove the spool against spring force, which will openthe PFC pump port and expose PFC pump pressureto the load check ball (10) and the signal port.

Lower PoppetThe lower poppet (9), lower pilot poppet (8) andspring (15) trap oil in the hitch cylinder circuit. Thelower pilot poppet (8) is held on its seat by a spring(15) and cylinder circuit pressure, which is allowed toget to the back side of the spool through an orifice(16) in the poppet.

Load Check BallThe load check ball (10) traps oil in the hitch cylindercircuit to hold the hitch in a raised position. The ball isunseated when PFC pump pressure exposed to theball by the raise spool over comes the pressure in thehitch cylinder circuit.

Manual Raise or Lower Control PinsThe raise and lower solenoid each contain a pin (14)in the center of the outer end that can be used tomanually activate the raise spool and lower controlpiston.

Overload Relief ValveThe overload relief valve (6) will allow oil from theraise/lower port to flow into the pilot chamber of thelower control piston (7). The piston moves to the rightand pulls the lower pilot poppet (8) off its seat whenthe hitch sees an overload.


35-15

HITCH CONTROL VALVE

RI02B003

23 4

5

6

7

8

9

10

11 1212 13 1314

1516

14

1

17

18

1. RAISE SOLENOID 10. LOAD CHECK BALL2. LOWER SOLENOID 11. PFC PUMP SUPPLY3. RAISE PILOT SPOOL 12. REGULATED PRESSURE SUPPLY4. LOWER PILOT SPOOL 13. RETURN PORT5. RAISE SPOOL 14. CONTROL PIN6. OVERLOAD RELIEF 15. SPRING7. LOWER CONTROL PISTON 16. ORIFICE8. LOWER PILOT POPPET 17. TANK PORT9. LOWER POPPET 18. RAISE/LOWER PORT


35-16

HITCH CONTROL VALVE

Neutral Function and Troubleshooting

Function

Hitch Control Valve in Neutral - The hitch controlvalve is a closed-center valve. In neutral there will beno electric current supplied to the raise or lowersolenoids (1 and 2) and no oil flow through the valve.The pilot spools (3 and 4) are blocking the supply ofoil from the regulated circuit. The raise spool (5) isblocking the supply of oil from the PFC system and isheld in place by a spring. The lower poppet (9), lowerpilot poppet (8) and the load check ball (10) areblocking the return of oil from the hitch cylindercircuit. The overload relief (6) also blocks the returnof oil from the hitch cylinder circuit. The lower poppet(9) is held on the seat by a spring (15) and the oiltrapped behind the poppet by the lower pilot poppet(8). Pressure from the hitch cylinder circuit getsbehind the lower poppet through an orifice (16) in theside of the poppet.

Troubleshooting

Problem - Hitch will not hold position or leaksdown.

1. Check the function of other systems(Transmission, Remote Valves),

A. If the other systems do not function properlyre fer t o t roubleshoo t ing o f t he nonfunctioning system.

B. If other systems function properly go to step2.

2. Check for HITCH fault codes.

A. If fault codes are found, follow proceduresoutlined in HITCH fault code troubleshootingin this section.

B. If no fault codes are found go to step 3.

3. With a load on the hitch, raise the hitch tomaximum height and disconnect the hitchcylinder drain line from the rear frame housing.

A. If oil flows from the drain line as the hitchsett les the cyl inder(s) is /are leakinginternally. Repair cylinders as needed.

B. If no oil flows from the drain line go to step4.

4. Check and repair the hitch valve as needed.

A. Check load check ball (10) and seat if seatis damaged replace the hitch valve.

B. Check the lower poppet (9) and seat, lowerpilot poppet (8) and seat. If any componentsa re damaged repa i r o r rep lace asnecessary.

C. Check overload relief assembly (6) andseat. If any components are damaged repairor replace as necessary.


35-17

HITCH CONTROL VALVE - NEUTRAL

RI02B003

23 4

5

6

7

8

9

10

11 1212 13 1314

1516

14

1

17

18



35-18

HITCH CONTROL VALVE

Raise Function and Troubleshooting

Function

Hitch Control Valve in Raise - To raise the hitch,the hitch raise solenoid (1) must be energized by theElectronic Hitch Controller. When the solenoid isenergized the armature in the solenoid moves towardthe valve contacting a control pin (14) which movesthe raise pilot spool (3) inward. The amount ofmovement of the spool depends on the amount ofcurrent applied to the solenoid by the controller. Theamount of current the controller applied to thesolenoid depends on the command information theoperator has sent to the controller. As the raise pilotspool (3) is shifted inward it meters regulatedpressure from the regulated circuit (12) to the lefthand side of raise spool (5).

The metered regulated pressure shifts the raisespool against the spring, allowing oil from the PFCpump circuit (11) to flow past the spool land to thehitch load check ball (10) which is seated bypressure from the hitch cylinders created by the loadon the cylinders. At the same time PFC standbypressure is sent through the signal port and signalcheck valve to the PFC pump compensator which willactivate the pump to increase flow output. Aspressure increases the load check ball is lifted off theseat allowing flow to the hitch cylinders.

The hitch will stop raising when the controller shutsoff current to the raise solenoid (1). Regulatedpressure acting on the right hand end of the raisepilot spool will shift the pilot spool outward shuttingoff regulated pressure supply (12) and opening thereturn port (13) to release the pressure on the raisespool. The spring will shift the raise spool (5) shuttingoff the PFC inlet port. The pressure in the hitchcylinders will seat the hitch load check ball (10)trapping the oil. The signal pressure will bleed offthrough the orifice in the raise spool (5) and allow thepump to return to low pressure standby.

Troubleshooting

Problem - Hitch will not raise

1. Check the function of other systems(Transmission, Remote Valves).

A. If other systems do not function properlyrefer to the troubleshooting section on thenon functioning system.

B. If other systems function properly go to step2.

2. Check for HITCH fault codes

A. If fault codes are present refer to fault codetroubleshooting in this section.

B. If no fault codes are present go to step 3.

3. Check for manual operation of the control valveby pushing in on the manual control pin (14) inthe center of the outer end of the raise solenoidwith a small punch or 1/8 inch rod.

A. If the hitch raises, test hitch raise solenoidfor proper electrical function and recheckHITCH fault codes.

B. If the hitch does not raise refer to theHydraulic Troubleshooting the PFC Systemand the regulated pressure system. If thehydraulic system functions properly go tostep C.

C. Check for free movement of the raise pilotspool (3) and raise spool (5). Repair orreplace as necessary.


35-19

HITCH CONTROL VALVERaise Function and Troubleshooting

RI02B006

23 4

5

6

7

89

10

111212 13 13

14

1516

14

1

17

18



35-20

HITCH CONTROL VALVE

Lower Function and Troubleshooting

Function

Hitch Valve in Lower - To lower the hitch, the lowersolenoid (2) must be energized by the ElectronicHitch Controller based on the commands entered bythe operator. Activation of the PFC system is notrequired to lower the hitch. When the lower solenoid(2) is energized the armature will move toward thevalve contacting the control pin (14) which pushesthe lower pilot spool (4) inward. The amount ofmovement depends on the amount of current that issent to the solenoid by the Electronic Hitch Controllerbased on the commands to the controller by theoperator. As the lower pilot spool (4) shifts it metersregulated pressure from the regulated pressuresupply (12), through the overload relief, to the lowercontrol piston (7). The piston moves to the right andpulls the lower pilot poppet (8) off its seat againstspring (15) tension. Pressure escapes to tankcreating a drop in pressure behind the lower poppet(9). The pressure in the raise/lower port now movesthe lower poppet off the seat. The hitch can nowlower as oil flows through to the tank port.

The hitch will stop lowering when the solenoid (2) isde-energized. Oil pressure acting on the left end ofthe lower pilot spool (4) moves the spool outwardclosing the regulated pressure supply (12) to thelower control piston (7). As the pressure drops on thepiston the pilot poppet (8) returns to its seat by springforce. With the pilot poppet port closed pressure fromthe hitch cylinders builds behind the lower poppet (9)through the orifice (16) forcing the poppet onto itsseat trapping oil in the hitch cylinders.

Troubleshooting

Problem - Hitch will not lower

1. Check the function of other systems(Transmission, Remote valves).

A. If other regulated pressure systems do notoperate properly refer to troubleshooting ofnonoperating system.

B. If other systems operate properly go to step2.

2. Check for HITCH fault codes.

A. If fault codes are found refer totroubleshooting of any fault found.

B. If no fault codes are found refer to step 3

3. Check for manual operation lower function bypushing in on the lower manual operating pin(14) in the center of the outer end of the lowersolenoid with a small punch or 1/8 inch rod.

A. If the hitch lowers, test hitch lower solenoid(2) for proper electrical function and recheckHITCH error codes.

B. If hitch does not lower refer to HydraulicTroubleshooting of the Regulated PressureSystem. If the hydraulic system functionsproperly go to step C.

C. Check the hitch control valve for freemovement of the lower pilot spool (4),thelower poppet (9) and the lower controlpiston (7). Check condition of all o-ring sealsand replace as necessary.


35-21

HITCH CONTROL VALVELower Function and Troubleshooting

RI02B007

23 4

5

6

7

89

10

11 1212 13 1314

1516

14

1

17

18



35-22

SETUP / ADJUSTMENT SEQUENCE

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Section 35 - Chapter 9HITCH SYSTEM - How it WorksCONTENTSTHREE POINT HITCHELECTRONIC HITCH CONTROLELECTRONIC HITCH CONTROL SYSTEM FEATURESEHC SYSTEM FEATURESHITCH CONTROL VALVEHITCH CONTROL VALVE - NEUTRALSETUP / ADJUSTMENT SEQUENCEReturn to Complete Contents

section 35 chapter 9 · 2010. 7. 1. · hitch controller. diagnostic and programming information...

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