A power voltage of 5 V is applied to the manifold absolute
pressure sensor power terminal (terminal No. 1) from the engine-ECU (terminal No. 72) and earthed
to the engine-ECU (terminal No. 31) from the manifold absolute pressure sensor (terminal No.
The sensor signal is inputted to the engine-ECU (terminal No. 37) from the manifold
absolute pressure sensor output terminal (terminal No. 2).
The manifold absolute pressure sensor converts the manifold
absolute pressure into a voltage signal and inputs the signal to the engine-ECU.
In response to the signal, the engine-ECU corrects the fuel injection amount, etc.
Battery positive voltage is 8 –
2 seconds later after the ignition switch has been in “ON” position
or the engine has started up.
The following 3 conditions are formed:
The engine cooling water temperature is from -5
to 80 °C.
The air intake temperature is from -5 to 80 °C.
The atmospheric pressure is from 76 to 120 kPa.
When an idle state and an engine rotation speed of 2,000 r/min continue for three
seconds, manifold absolute pressures are read and the difference between them goes under 800
Pa for 1 second.