Case Magnum 7210, Сервисный бюллетень

Страница: 11 / 26

Service Bulletin
NTF? SB 026 96
Magnum Hitch Diagnostic Codes and Service Manual update
Page 11
of
26
7200
SERIES HITCH CALIBRATION PROCEDURE
All
components and harnesses must be in good working order prior to calibration.
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1.
2.
3.
4.
5.
6.
7.
8.
The position control potentiometer must be set to 4.85 0.1 volts DC when the position control
lever is
at its maximum height.
Before starting the calibration process, make sure that the hitch is free to move all the way
between the cylinder’s minimum and maximum limits with no load. Make sure that no
interference exists during the movement and the back of the tractor is clear of all objects.
Calibration cannot be performed while the tractor is moving.
Calibration must be performed without a load.
Install
CAS 1638 test box with CAS 1897 adapter harness (black) per the Service Manual section 8009
page 4. CAS 1638 test box slide switch should be in the ON position.
Only center the hitch, if error code indicates that the hitch valve (null) is not centered, see page 13 for error
codes. To center hitch valve, see Service Manual section 8009 pages 4 though 7. If hitch Null adjustment
tool CAS 2028 is used a 5 setting is acceptable. Disregard All Null tool error codes (7200 series tractors
only).
Record and clear any error codes prior to adjustment. See reading and erasing error codes on page 5 of this
bulletin.
With the ignition switch in the ON position, place the hitch position lever in the FULLY RAISED,
TRANSPORT position and 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 place range, do not perform test with
the DVM in the auto
ranging mode. Move the position lever forward though the range, the voltage should smoothly drop to
approximately 1.4 volts
D.C.
in the fully lowered position. When moving the position lever rearward toward
the transport position the voltage should smoothly increase back to its original 4.85 volts D.C. once the
transport position is reached.
- If the voltage does not return to its original 4.85 volts D.C. or the voltage is intermittent, replace the
potentiometer.
- If the voltage goes to “0” or above 4.85 volts, replace the potentiometer.
With the position lever fully rearward (transport position), start the engine while holding the hitch switch in the
MOMENTARY position. Release the switch when the letter “r” appears in the diagnostic display.
“C” will appear in the diagnostic display if there are no failures that will prevent calibration. If “C” does not
appear, See reading and erasing error codes on page 5 of this bulletin.
Note: If a “g” appears during calibration, the draft pins or its wiring circuit is failed.
Note: In some cases a “g” may appear in the display. The hitch control module is asking “does the system
have two load sensing pins ?” Answer yes by pressing the hitch switch to the momentary position then
release. Normally the control module will sense two pin and not ask. See page 19 for more
information.
Press the hitch switch to the MOMENTARY position and release, “c” should appear on the diagnostic
display.