Method for determining the pressure prevailing in a fuel injection ramp of an internal combustion engine and corresponding device

Process for determining the pressure prevailing in an injection manifold (14) of fuel for an internal combustion engine, said engine being particularly provided with:

• a pressure sensor (18) mounted in the injection manifold, said sensor being adapted to operate with maximum precision between a lower limit and an upper limit of pressure,
• a pump (13) for pressurizing the fuel,
• a feeding pump (11) supplying the circuit with fuel at a feeding pressure below the lower limit of the range of maximum precision of the sensor, and
• a pressure regulator (15), said process being characterized in that it consists in:
• (a) supplying the feeding pump (11) with fuel, such that the injection manifold is supplied with fuel at the feeding pressure,
• (b) measuring the pressure prevailing in the injection manifold (14) with the pressure sensor (18), when the fuel is at the feeding pressure,
• (c) deducing therefrom the percentage of error (e) of the pressure sensor, and memorizing this error,
• (d) establishing a law of linear decrease of this error, between the feeding pressure and the lower limit of the range of maximum precision of the sensor, and
• (e) deducing therefrom, for each value of pressure measured by the sensor between the feeding pressure and the lower pressure limit, the real value of the pressure of the fuel in the injection manifold, to correct the quantity of injected fuel.