Abstract: Process for calculating the torque of an internal combustion engine having electronic injection. The method includes having a cogged target with an indexed reference rotating before a fixed sensor. The defects of the target are corrected by distinguishing the combustion interval of the target from the reference. A term assigned to each interval is $g(b)i which is determined in the absence of combustion from the measurement of the engine torque which is proportional to the pressure in the commutator represented by the equation Ci=K.Pcoll=&agr;(&Sgr;N+$g(b)i)N2 where Ci is the engine torque, Pcoll is the pressure, N is the engine power, K is the proportionality factor and &agr; is a constant term.

Abstract: An apparatus and method for diagnosing the condition of a sensor in an internal combustion engine upstream from the catalytic converter. The diagnosis utilizes a signal from a second non-linear probe downstream from the catalytic converter. This signal is processed to give a signal that is filtered. The filtered signal is in turn compared with maximum and minimum values. The upstream probe is considered to be correct if the signal falls between these two values or faulty if it falls outside the values.