Autocontrol 5.2, General; Additional Functions In Ac 5.2; Automatic Calibrations; Automatic Speed Change Of Dps - Valtra 6000 Workshop Manual

37. Autocontrol 5.2 (K41107---)

1. Autocontrol 5.2, general

Note! AC 5.2 replaces the AC 5 system in 6250Hi ---8950Hi
tractors from ser. no. K41107 incl.
A. Additional functions in AC 5.2
a) Automatic traction control (Autotraction ON/
OFF)
See page 371/3.
b) Fault codes
Fault codes have a fault code memory (in fault code mode
FI), in which can be checked and deleted from display. The
memory stores three latest fault codes and running hours of
the codes (control unit running hours).
New fault codes have been added in the system, see
pages 371/5 and 6.
c) Automatic speed change of DPS
AutoDPS Auto2 function has been changes so that it func-
tions in fixed speed change revs and driver can set easily
the revs, see page 371/4.
d) Speed Matching
When using the HiShift button the control unit adapts the
DPS speed so that it is suitable for driving situation when
the mechanical gear has been changed, see page 371/4 or
when traction is disengaged and re ---engaged with clutch
pedal, with HiShift or with the shuttle lever.
e) Automatic calibrations
The automatic calibration is activated in setting mode FIII,
and it calibrates the initial pressures and pre ---filling times of
the shuttle clutches, for DPS and PTO clutches only the
initial pressures, see page 371/11. The calibrations can
also be done manually, see page 370/24D. Manual calibra-
tion of PTO clutch, see page 371/12.
f. Calibrations of clutch and gas pedals and
pedal position sensors
The activating point of the clutch pedal limit switch has
been changed to zero point of the pedal position. Now the
activating point of the switch is not necessary to adjust so
excatly as earlier.
The pedal calibrations have been changed so that the con-
trol unit accepts more unaccurate signal voltages for the
position sensors. Calibrations, see page 370/15.
The position sensors are different and they have been fas-
tened so that no adjustment is needed, see pages 371/13
and 14.
With the aid of the clutch pedal ratio index the pedal engag-
ing point can be adjusted separately in F --- and R ---direc-
tions in the setting mode FIII, see page 371/10.
1. 8. 2000
1. 9. 2002
g) Reverse drive controls (TwinTrac)
The reverse drive controls have separate digital inputs in
the control unit A1. The position of the seat (d14) deter-
mines which one of digital inputs the control unit uses.
h) Seat switch
The activating delay is normally 6 seconds, but 30 sec-
onds, if the clutch pedal has been depressed, see page
370/24.
i) PTO start
The PTO start push buttons in the mudguards (option) have
separate digital inputs in the control unit. The PTO rocker
switch in the cab functions without delay and the push but-
ton in the mudguard has delay of 3 sec.
j) Zero -- point offset of the shuttle outputs
(program versions 80...85)
Into the shuttle clutch, which is unpressurised, is fed an oil
pressure of 0,1...0,5 bar, so that no air can enter into the oil
passages. This happens if either of the driving directions is
engaged.
Note! The pistons in the shuttle have been made smaller
and the spring force has been increased. The emptying
valve has been removed from the piston for reverse driving,
see page 440/19A. In connection with this shuttle the AC
5.2 programs must always be used.
NOTE! Initial pressures of the shuttle clutches have been
raised up to about 3,5 bar (earlier about 2 bar).
k) Other modifications
With the aid of output P7 the control unit switches on and
off the auxiliary relay K52 of the starter.
Control unit output P8 controls the 4WD automatics (relay
K27).
The control unit changes no more DPS speed in driving
speed of 65 km/h but gives only a fault code.
NOTE! AC 5.2 has a new control unit, which can be used
also in the earlier manufactured tractors with AC 5, but a
different programs must be used.
AC 5.2 has only one main program there are several para-
meter files according to the tractor model and engine
power.
In the DPS ---gear the spring force of clutch C3 has been
increased. Also oil way modifications have been done, see
page 440/15C.
Parking brake! A non ---return valve from ser. no. K50440
incl. has been fitted in the low pressure circuit, which to-
gether with program modification retards the pressure drop
in cases, in which engine stops during running ( e.g. fuel
runs out). A modification has been made in AC 5.2 pro-
gram, which disengages all multi ---disc clutches if tractor's
engine stops when the driving speed is over 5 km/h. In this
case the parking brake cylinder starts to brake after 15---30
seconds when the tractor has been already stopped.
The function of output DO5 has been changed inverse.
Earlier this output was parking brake on. Now parking
brake off. The control unit controls direct the valve and no
more via an auxiliary relay.
154
Model Code
371
6250-- 8950
Page
2