Injection And Ignition - Ducati Diavel Workshop Manual

Introduction to the engine control system
An incorrect fuel flow rate and/or pressure may cause engine malfunction, resulting in variation in the self-adaptive
parameters defined by the engine control unit. Fuel flow rate and/or pressure values deviating substantially from the
rated values will result in an incorrectly generated fuel-air mixture that is too rich or too lean and, as a result,
compromise the measurements made by the oxygen sensors. After changing the fuel pump and/or fuel pressure
regulator, always reset the self-adaptive parameters with the DDS and then use the motorcycle (even by simply running
at idle speed) to allow the parameters themselves to recalibrate correctly.

Injection and ignition

Introduction
Ignition is via a single stick coil per cylinder installed in the spark plug well. Each thermal unit is supplied by a single
injector, placed under the throttle valve. The amount of fuel injected and the ignition advances are determined by the
control unit specifically for each cylinder. These basic measures are then corrected by the control unit, according to the
information supplied by different sensors fitted on the engine and applying certain strategies, in order to obtain the
definitive signals of activation. The DTC function (Ducati Traction Control, integrated in the BBS) acts on throttle valve
aperture only to control traction as necessary. The DTC function integrated in the BBS communicates with the engine
control unit via the CAN network.
Determination of quantity of fuel injected and ignition advance
The base quantity of fuel injected (defined by the base maps) is determined by the engine control unit using one of two
different strategies depending on the operating conditions of the engine:
- If the throttle valve aperture is below a specific threshold, the base quantity of fuel injected is determined using a
strategy denominated 'speed-density' (engine speed-intake manifold pressure). There is therefore one base fuel quantity
map with coordinates correlating the quantity of fuel injected with engine speed-pressure for cylinder 1 (horizontal) and
another for cylinder 2 (vertical)
- If the throttle valve aperture is over a specific threshold, the base quantity of fuel injected is determined using a strategy
denominated α-n (throttle valve aperture angle-engine speed). There is therefore one base fuel quantity map with
coordinates correlating the quantity of fuel injected with engine speed-throttle valve aperture for cylinder 1 (horizontal)
and another for cylinder 2 (vertical)
- At intermediate throttle valve apertures between the two thresholds described above, the base quantity of fuel injected is
determined by applying the two strategies simultaneously
The base ignition advance (defined by the base maps), is determined by the engine control unit using the α-n (throttle
valve aperture angle-engine speed) strategy. There is therefore one base ignition advance map with coordinates
correlating the quantity of fuel injected with engine speed-throttle valve aperture for cylinder 1 (horizontal) and another
for cylinder 2 (vertical).
The two diagrams illustrate how the engine control unit determines the base quantity of fuel injected and the base ignition
advance.