Method for diagnosing an electrical circuit

Abstract

A method for diagnosing an electrical circuit including at least one electrical device, an actuator for the device controlled by a high side actuating switch and a low side actuating switch, and at least one additional switch not in series with any of the HS or LS switch, the method including: to each of the possible statuses of the circuit, giving a code; sequentially putting the circuit in at least some of these statuses for a given time period; during each of these periods, measuring voltage and/or current in different parts of the circuit and giving a code to the measurement; and establishing a diagnosis of correct functioning or of a malfunctioning of at least some elements of the circuit according to a pre-established correlation between the status codes and the measurement codes.

1 . (canceled) 
     
     
         2 . A method for diagnosing an electrical circuit including at least one electrical device, an actuator for the device controlled by a high side (HS) actuating switch and a low side (LS) actuating switch, and at least one additional switch not being in series with any of the HS actuating or LS actuating switch, the method comprising:
 giving a status code to each of a plurality of possible statuses of the circuit;   sequentially putting the circuit in at least some of the plurality of possible statuses for a given time period;   during each given time period measuring voltage and/or current in different parts of the circuit and giving a measurement code to the measurement; and   establishing a diagnosis of correct functioning or of a malfunctioning of at least some elements of the circuit according to a pre-established correlation between the status codes and the measurement codes;   wherein both the HS actuating switch and the LS actuating switch of the actuator comprise an additional switch or diagnosis switch in parallel with the actuating switch.   
     
     
         3 . A method according to  claim 2  comprising: defining a three digit status code, each digit having three possible values. 
     
     
         4 . A method according to  claim 3  comprising:
 defining a six digit measurement code; 
 listing the different possible errors to be detected; and 
 establishing tables giving the measurement codes associated with different status codes and the possible errors associated therewith for each possible diagnosis condition.