Volkswagen 1.9 tdi, Руководство пользователя, Страница: 50 / 67

46
Engine Management
The actual moment at which the pump/
injector solenoid valve closes (BIP) is used
by the Diesel Direct Fuel Injection Engine
Control Module J248 to calculate the point
of actuation for the next injection period.
If the actual BIP deviates from the mapped
details stored in the Diesel Direct Fuel
Injection Engine Control Module J248, it will
correct the point of valve actuation (start of
injection) for the next combustion cycle.
To detect pump/injector solenoid valve
faults, the Diesel Direct Fuel Injection
Engine Control Module J248 evaluates the
BIP position from the current flow pattern.
If there are no faults, BIP will be within the
control limit. If this is not the case, the
valve is faulty.
Effects of failure
If a fault is detected at the solenoid valve,
start of injection is determined based on
fixed values from the control map.
Regulation is no longer possible and
performance is impaired.
Example
If there is air inside the pump/injector, the
solenoid valve needle has a low resistance
when it closes. The valve closes quickly
and the BIP is earlier than expected.
In this case, the self-diagnosis indicates the
following fault message:
“BIP below control limit”