Yamaha YZF-R1P Service Manual page 34

Intake air pressure sensor and atmospheric pressure sensor
• Intake air pressure sensor
The intake air pressure sensor is used for measuring the intake air volume. The intake air volume
of every intake stroke is proportionate to the intake air pressure. Therefore, the intake air volume
can be measured by measuring the intake air pressure. The intake air pressure sensor converts
the measured intake air pressure into electrical signals and sends those signals to the ECU. When
the intake air pressure is introduced into the sensor unit, which contains a vacuum chamber on
one side of the silicon diaphragm, the silicon chip that is mounted on the silicon diaphragm con-
verts the intake air pressure into electrical signals. Then, an integrated circuit (IC) amplifies and
adjusts the signals and makes temperature compensations, in order to generate electrical signals
that are proportionate to the pressure.
• Atmospheric pressure sensor
The atmospheric pressure sensor is used for making compensations to the changes in the air
density caused by the changes in the atmospheric pressure (particularly at high altitudes). The
operating principle and function of the atmospheric pressure sensor are the same as those of the
aforementioned intake air pressure sensor.
1 EMI shield
2 Sensor unit
3 Through condenser
4 Hybrid IC
5 Cap
6 Silicon diaphragm
7 Vacuum chamber
8 Solder
9 Silicon chip
0 Gold wire
1 - 13
FEATURES
A Lead pin
B Stem
C Pressure induction pipe
D Atmospheric pressure,
intake air pressure
GEN
INFO
È Output voltage
É Input pressure