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Service Bulletin NTR SB 026 96
Magnum Hitch Diagnostic Codes and Service Manual update

Page 12 of 26

HITCH CALIBRATION PROCEDURE CONTINUED

9. Press the hitch switch to the MOMENTARY position and release. “11” should appear on the diagnostic

1 0 .

11.

12.

13.

display. Note: The control module is asking you if the tractor has an upper limit knob.

Press the hitch switch to the MOMENTARY position and release to answer “yes”. A “8” should appear on

the diagnostic display. Note: The “8” means the system is ready to calibrate.

Hold the hitch switch in the MOMENTARY position until the hitch has completely lowered, then release.
Do 

not release switch before hitch is fully lowered. A “6” should appear on the diagnostic display.

With the hitch in the FULLY LOWERED position and the test box at position 2, set D.C. voltage to .9 

 .1

volts, at the hitch rockshaft pot above the right rear axle housing. See Service Manual section 8009-9 steps
24 & 25.

Test Rockshaft pot: 

Set the DVM to the 2 decimal place range, do not perform test with the DVM in the

auto ranging mode. View the DVM voltage while the hitch is being raised in step 16. As the hitch raises the
voltage should smoothly increase from .9   .1 to approximately 4.70   .2 volts D.C. in the fully raised
position.

14. Move the hitch lever to the full raise position. Raise the hitch by pressing the hitch switch to the

MOMENTARY position and releasing the switch (The hitch position lever should still be in the transport
position). A “9” should appear on the diagnostic display. The hitch should raise after a delay. If any reason
occurs where the hitch movement should be stopped during this process, toggle the switch to the UP
position.

15. Move the hitch position lever to the fully lowered position. Make sure the stop is not in the way. The lever

must be all the way down.

16. Test Rockshaft pot: 

Set the DVM to the 2 decimal place range, do not perform test with the DVM in the

auto ranging mode. View the DVM voltage while the hitch is being lowered in step 19. As the hitch lowers
the voltage should smoothly decrease from 4.70   .2 to approximately to .9   .1 volts D.C. in the fully

lowered position.

17.

18.

19.

Lower the hitch by pressing the hitch switch to the MOMENTARY position and release. After a delay, the
hitch will lower to full down. A 

“U” 

should appear on the diagnostic display. 

If 

any reason occurs for the

hitch movement to be stopped during the process, toggle the hitch switch to the UP position.

When the hitch has fully lowered, press the hitch switch to the MOMENTARY position and release. “0”
should appear on the diagnostic display, meaning calibration has been successful.

Check for and clear any error codes from memory.

SEE PAGE 20 FOR INFORMATION ON TESTING THE ROCKSHAFT AND

POSITION LEVER POTENTIOMETERS

Summary of Contents for Magnum 7210

Page 1: ...bration procedure This bulletin will cover the following items 1 General information page 2 2 General testing of the hitch system Reading and erasing error codes page 3 4 3 page 5 4 Hitch performance...

Page 2: ...ay not show up as error codes The hitch must be recalibrated every time an hitch component is replaced or adjusted An empty hitch may move up slightly when the tractor is backed up if the load setting...

Page 3: ...number JJA0064978 a Check battery and cab power stud located on cab floor RH console b Fuse 7 may be defective c Turn key ON and check pin 14 of the 16 pin connector for power d Bad ground to control...

Page 4: ...ormation Electrically testing the hitch valve solenoid Disconnect the 16 pin connector from the hitch control module Test the hitch harness and solenoid resistance Solenoid spec 3 8 4 2 ohms 1 Raise s...

Page 5: ...ve been recorded recorded first code will appear now A If any error codes have been I Toggle to UP position Toggle to DOWN position I Down momentary and release I c l Next error code Example only Repe...

Page 6: ...responding to the various error code displays are HALT LIMP DEGRADED 2 and DEGRADED 1 each failure mode will generate different modes of operation as follows MODE OPERATIONAL HITCH FUNCTIONS HALT Hitc...

Page 7: ...cuit failed i EEPROM failure The system cannot read calibrated values or errors HALT Tractor has not been calibrated Only appears when controller has been replaced HALT Calibrate hitch controller 1 Sh...

Page 8: ...r El Relay primary or contacts problem Watchdog circuit problem High battery supply voltage Upper limit circuit failed Load control circuit failure 5 Both draft pin sensors failed or one draft pin sen...

Page 9: ...er rest wire harness for damaged wires or connectors 4 Lamp circuit failure DEGRADED 1 Replace lamp lest wires to lamp for damaged wires or connectors DEGRADED 1 Capture the hitch and lower the hitch...

Page 10: ...oller RAISE LOWER switch and position control failure LIMP Replace RAISE LOWER switch and Test position sensor wire harness Replace posrtion potentiometer Replace controller RAISE LOWER switch failure...

Page 11: ...the test box at position 1 set D C voltage to 4 85 1 volts Adjust the hitch position pot in the console if needed See Service Manual 8009 8 steps 16 21 Test position pot Set the DVM to the 2 decimal...

Page 12: ...full raise position Raise the hitch by pressing the hitch switch to the MOMENTARY position and releasing the switch The hitch position lever should still be in the transport position A 9 should appear...

Page 13: ...sition command is not at maximum Raise PWM Pulse Width Modulation threshold is above 55 Raise PWM Pulse Width Modulation threshold is below 4 Full raise current detection 100 Pulse With Modulation is...

Page 14: ...low A Replace coil 0 B Battery voltage is very high B Test tractor battery circuit output Hitch valve null out of adjustment C Valve failure C Repair or replace hitch control valve Md A Operator did n...

Page 15: ...r leaking 9 High pressure stand by not in spec 3 Hitch will not lower A B C D E F Perform Electronic Hitch Control troubleshooting Troubleshooting hitch system page 4 Hitch drop speed control set inco...

Page 16: ...er If hitch leaks still leaks down go to step B Testing the hitch rockshaft cylinder and the cushion relief valve 1 2 3 4 5 Lower the hitch completely Disconnect the hitch supply line to the rockshaft...

Page 17: ...S Pin B to pin C 3 8 4 2 OHMS If the plunger in the solenoid valve is off center to the right the hitch will drift up If the plunger in the solenoid valve is off center to the left the hitch will drif...

Page 18: ...lockout plunger spool is not shifted or moved with oil pressure when the hitch is raised The piston pump oil pressure at the left end of the spool will unseat the load check poppet to raise the hitch...

Page 19: ...isplay will not work on 7100 series 235010A1 ELIMINATING DRAFT CONTROL FROM THE MAGNUM TRACTOR Load pins draft control can be eliminated from the tractor by simply unplugging the draft pins and reprog...

Page 20: ...ximately to 9 1 volts D C in the fully lowered position Note To completely lower the hitch the up down switch must be double clicked and held in the momentary position Note The over all range of the r...

Page 21: ...Pin B of the Load control potentiometer signal Pin C of the Load control potentiometer ground See secondary control panel for potentiometer spec See page 22 Pin A of the Travel control potentiometer p...

Page 22: ...al Pin A of the Hitch position rockshaft potentiometer ground See Testing hitch potentiometer on page 20 See correction to wiring schematic on page 26 OHMS 195 000 195 000 OHMS OHMS Cab floor I d b d...

Page 23: ...lay To terminal A of the fender mounted hitch control switches POWER SUPPLY TRACTORS ABOVE SERIAL NUMBER JJA0064978 Turn key switch ON the ignition cab relay should provide power to fuse 7 If fuse 7 i...

Page 24: ......

Page 25: ...7 Terminal 87 of the EDC relay supplies 12 volt power to the following To pin number 14 of the 16 pin connector To terminal 30 of the hitch enable relay To terminal 5 of the up down switch To terminal...

Page 26: ...date Page 26 of 26 CORRECTION TO WIRING SCHEMATIC The rockshaft position sensor wiring schematic is incorrect in the Service Manual schematic found in section 4002 page 27 See below for correction INC...

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