Chapter VI Fuel System
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
393
Fig. 6-1-24 XINFENG common-rail system
ECU
Fig. 6-1-25Coolant temperature sensor
Fig. 6-1-26 Camshaft position sensor
2.6.5 Installing the ECU
Fix the ECU to the relative installation position of the
complete vehicle with bolts. It is unallowable to install
the ECU on the engine.
2.7 Sensors
2.7.1 Coolant Temperature Sensor
For the coolant temperature sensor, see Fig. 6-1-25.
The temperature resistance of coolant temperature
sensor is a part of the 5V voltage division circuit.Both
ends of coolant temperature sensor are connected with
energized circuit.When the temperature resistance of
coolant temperature sensor changes with the
temperature, the voltage of energized circuit varies and
is input into the analog-to-digital interface conversion
circuit of ECU.
Installating the coolant temperature sensor: install the
sensor to the screw hole by the required torque after
coating the sealant on the sensor thread.
LOCTITE 243 thread fixing agent
Tightening torque for the fastening bolt
components of fuel injector ballast:
18 N•m ~ 22 N•m
After the installation, make sure that the sensor is
sealed so strictly that no water leakage will occur.
2.7.2 Camshaft Position Sensor
Camshaft position sensor works on the principle of Hall
effect. The trigger wheel of a ferromagnet rotates
together with the camshaft.The integrated Hall-effect
circuit is installed between trigger wheel and permanent
magnet which produces a magnetic field perpendicular
to the Hall-effct elements. See Fig. 6-1-28.
If one of the trigger wheel teeth travel through the
intercepting linear sensor elements (semiconductor
chips), the intensity of the magnetic field normal to
Hall-effect elements will be changed. Consequently, the
electrons in the direction of long shaft, driven by the
voltage, will deviate towards the direction perpendicular
to the current and then produce the Grade-mV voltage
signals in the latter direction. The amplitude of such a
voltage signal is involved with the sensor speed relative
to the trigger wheel.The calculation circuit incorporated
with the sensor’s Hall-effect integrated circuit
processes these signals and output them as
square-wave signals.
Installing the camshaft position sensor: check whether
the O-ring has been properly mounted on the camshaft
position sensor, install the sensor into the hole of
Electronic
connector
Housing
Coolant
NTC
resistance
Camshaft
position
sensor
