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A80 Pro Intelligent Diagnosis System
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（1）ECU (Electronic Control Unit)
The ECU is the control center of the electronically controlled engine, which can control the
action of each actuator by receiving the engine operation information transmitted by each sensor.
The ECU calculates the signals of the external sensors and limits them to the allowed voltage
levels. The microprocessor calculates the injection time and injection timing from the input data and
the stored MAP chart and converts these times into a time varying voltage process that matches the
engine operation. Due to the high precision required, the engine's operation is highly variable, so the
calculation efficiency should be high.
The final stage is controlled by the output voltage, which provides sufficient power to regulate
the common rail pressure operating units (Actuator) and shut off the plunger supply. In addition, the
actuator controls engine functions (e.g. exhaust gas recirculation actuators, boost pressure actuators,
electric oil pump actuators) and other auxiliary functions (e.g. fan relays, auxiliary heating relays,
preheating relays, air conditioning units). The final stage is protected by short circuit protection and
electrical overload. This type of fault and wire disconnection is fed back to the microprocessor. The
diagnostic function at the end of the injector also identifies defective signal changes. In addition, some
of the output signals are transmitted to other systems of the vehicle via the interface. Within the scope
of the safety program, the ECU also monitors the entire fuel injection system.
The ECU also contains a monitoring module. The ECU and the monitoring module monitor each
other and if a fault is found, any one of them can be separated from the other and cut off the fuel.
（2）Camshaft speed sensor
The camshaft controls the intake and exhaust valves, which rotate at half the crankshaft speed. Its
position determines that the piston moving up the dead point is in the compression stroke and then in
the firing or exhaust stroke. This information is not available from the crankshaft position during
starting. In contrast, the information generated by the crankshaft sensor is sufficient to determine the
engine state while the vehicle is running. That is to say, the ECU still knows the engine state when the
camshaft speed sensor fails during vehicle operation.
The camshaft speed sensor uses the Hall Effect to determine the position of the camshaft. The
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