Actron CP9087 - Manual (Page 36)

2-28
Testing Sensors
Section 2
The computer needs to know air pressure both
outside and inside the manifold to properly adjust
the air/fuel mixture and ignition timing for varying
engine load and altitude conditions. On turbo-
charged engines, the computer also uses the
sensor to monitor boost pressure and operate the
wastegate accordingly.
How it is
used?
What is It?
This sensor is an electronic module which sends a
signal to the computer indicating atmospheric
pressure and/or engine vacuum. Depending upon
sensor type, the signal may be a dc voltage or a
frequency. More pressure (less vacuum) makes the
sensor signal increase (higher voltage or fre-
quency). The computer supplies power and ground
to the sensor.
Manifold Absolute Pressure (MAP) Sensor
Barometric Pressure (BARO) Sens
TOYOTA/HONDA
GM/CHRYSLER
FORD