Patent ID: 7293452

Claim:
A method for determining the ambient pressure in a turbocharged engine having a butterfly valve ( 18 ) placed between a heat exchange chamber ( 16 ) and an intake manifold ( 20 ), a compressor ( 14 ) being provided to compress the air in the heat exchange chamber ( 16 ) and the engine being fitted with means for indicating the pressure in the heat exchange chamber ( 16 ), characterized in that it comprises the following steps: detecting an opening of the butterfly valve ( 18 ), measuring the pressure (MAP_UP) in the heat exchange chamber ( 16 ), determining the ambient pressure (AMP) by measuring the pressure (MAP_UP) in the heat exchange chamber ( 16 ) at a predetermined instant defined with respect to a characteristic point on the curve ( 24 , 24 ′) of pressure (MAP_UP) in the heat exchange chamber ( 16 ) as a function of time, the ambient pressure (AMP) then being equal to the pressure measured in the heat exchange chamber ( 16 ).