PROCEDURE FOR MEASURING THE ATMOSPHERIC PRESSURE FOR AN INTERNAL COMBUSTION MOTOR

摘要

1. A process for measuring atmospheric pressure in an internal combustion engine using an apparatus comprising a pressure sensor (1) intended to measure the pressure in the air intake manifold and connected to an electronic computer (2), and an electically operated valve (3) which is connected in series by a pneumatic connection (4) to the pressure sensor (1) and which can be switched either to the air intake manifold or to the free air, characterised in that the electronic computer (2) controls switching of the electrically operated valve (3) : - to the free air on the one hand when voltage is applied to the electronic computer (2), with the engine stationary, and when the computer (2) detects a deceleration cut-off with an engine speed higher than a given threshold, and - to the intake manifold on the other hand either when acquisition of the value of atmospheric pressure is effected at the end of a given time delay or when the deceleration cut-off effect is inhibited.