Apparatus for determining a failure of wheel speed sensors

An apparatus for determining a failure of a wheel speed detection system of an automotive vehicle including an internal combustion engine, an automatic transmission having a torque converter, and a plurality of wheels, said wheel speed detection system including a plurality of wheel speed sensors for detecting respective wheel speeds of said plurality of wheels, for control of torques transmitted to at least two of said plurality of wheels via said automatic transmission,

• the apparatus comprising:
• engine rotational speed detection means for detecting a rotational speed of said engine;
• input-output rotational speed ratio calculation means for calculating an input-output rotational speed ratio of said torque converter based on an input rotational speed and an output rotational speed of said torque converter;
• shift range detection means for detecting a shift range of said automatic transmission;
• traveling state determination means for determining whether or not said vehicle is traveling, based on said detected engine rotational speed and said calculated input-output rotational speed ratio when said shift range detected by said shift range detection means is a traveling range;
• sensor failure determination means for determining that said wheel speed detection system has failed if it is determined by said traveling state determination means that said vehicle is traveling, and at the same time, at least one of said plurality of wheel speed sensors indicates a stopped state of a corresponding one of said wheels;
• and
• failure determination inhibition means for inhibiting failure determination by said sensor failure determination means for a predetermined time period after said shift range detection means detects that said shift range of said automatic transmission is switched to said traveling range from a neutral state of said automatic transmission.