Cut-Off Option; Idle Tps Hysteresis - A.E.B. AEB215 Manuel D'utilisation

OPTIONAL CONFIGURATIONS
CUT-OFF OPTION (Fig. 56)
The CUT-OFF OPTION is useful for those engines whose RPM decrease
very slowly during deceleration.
During CUT-OFF, the LEONARDO behaves as follows: when the gas
pedal is released (IDLE T.P.S.), the LEONARDO E.C.U. limits the fuel
flow's cross-section by bringing the stepper motor to a partially closed
position. This position can be set by means of the "ACTUATOR
POSITION DURING CUT-OFF" function, which comes factory set
at 80 steps.
The LEONARDO exits this condition automatically when the engine
RPM goes below a certain value ("LOWER RPM CUT-OFF
THRESHOLD") which comes factory set at 1700 RPM.
This value is also adjustable to optimize different engines.
If the gas pedal is depressed during the CUT-OFF mode, the stepper
motor is brought back to the default position even if the "LOWER RPM
CUT-OFF THRESHOLD" threshold has not been reached.
NOTE: before engaging the CUT-OFF function, the LEONARDO
E.C.U. must have learned the carburetion parameters.
LOWER RPM CUT-OFF THRESHOLD (Fig. 57)
When enabling the CUT-OFF option, it is necessary to enter the RPM
threshold below which the function is disabled, thus bringing the
LEONARDO back to its normal operation. If the engine is still
accelerated when it goes below the RPM at which the CUT-OFF
function has been programmed to disengage, it is necessary to
further reduce the threshold.
The above function is displayed only when the CUT-OFF option is
enabled.
NOTE: we remind you that the threshold is factory set at
1700 RPM.
ACTUATOR POSITION DURING CUT-OFF (Fig. 58)
When enabling the CUT-OFF option, it is necessary to set the position
to which the stepper motor must go during the CUT-OFF phase.
Before changing this parameter, it is best to read what the default
value of the stepper motor is, and enter as "ACTUATOR POSITION
DURING CUT-OFF" a value that is slightly lower, keeping in mind that
0 is where the fuel is totally shut and 240 is where the fuel is totally
open. If the engine still does not decelerate, lower the number of
steps until it decelerates correctly.
The above function is displayed only when the CUT-OFF option is
enabled.
NOTE: we remind you that the threshold is factory set at 80
steps.
IDLE TPS HYSTERESIS (Fig. 59)
On many new vehicles the idle control is achieved by a small electric
motor that acts directly on the throttle. This continuous change in
the position of the butterfly causes a change in the output of the
T.P.S. that may adversely affect the LEONARDO, which could interpret
this variation as an out-of-idle condition.
The idle T.P.S. hysteresis is a voltage which, when summed to the
value of the idle voltage, increases total voltage thus making the idle
less sensitive to these small variations.
Is215-2 Rev. 110105-2
LEONARDO

CUT-OFF OPTION

ENGAGED
Fig. 56
LOWER RPM CUT-OFF
THRESHOLD
1700 RPM
Fig. 57
ACTUATOR POSITION
DURING CUT-OFF
80
Fig. 58

IDLE TPS HYSTERESIS

0.13 V
Fig. 59
57 - 188