A80 BT Intelligent Diagnosis System
50
path. The plug-in sensor can be mounted in the air filter or in the
measuring tube of the air guiding section. The measuring tubes are
available in a variety of sizes depending on the maximum air flow
required by the engine. The relationship between signal voltage and air
mass flow can be divided into two signal ranges of reverse and forward
flow. In order to improve the measurement accuracy, the measurement
signal is correlated with a reference voltage derived from engine control.
The characteristics of the characteristic curve are designed such that the
wire breakage can be detected during the diagnosis of the repair shop,
for example by means of engine control. To determine the intake air
temperature, a temperature sensor can be built in.
（
5
）
Intake pressure sensor
The intake pressure sensor detects the absolute pressure of the
intake manifold behind the throttle and the valve. It detects the change of
the absolute pressure in the manifold according to the engine speed and
the load, and then converts it into a signal voltage and sends it to the
controller (ECU). The ECU controls and corrects the fuel injection
amount based on this signal voltage.
Note: The sensor pressure port should be perpendicular to the
mounting surface. The maximum angle between the sensor and the
vertical direction should not exceed 60 degrees. The sensor should not be