Abstract: Herein disclosed is a revolution signal processing system for an electronic controller to ensure safe operation of a vehicle having an automatic transmission. The system includes: an input shaft revolution sensor for outputting an input shaft r.p.m. signal; a vehicle speed sensor for outputting a vehicle speed signal; signal processors for determining the r.p.m.'s of the two sensors in response to the two output signals of the same; a gear position sensor for outputting a gear position signal; a gear position detector for detecting the gear position of the automatic transmission; and a self-testing backup. When the gear position detector detects that the transmission is in a gear position other than the neutral position, and if one of the output signals of the two sensors exhibits an r.p.m. equal to or higher than a predetermined value, whereas the other of the same exhibits an abnormally lower value or an r.p.m.

Abstract: An automatic clutch control system and method for controlling a clutch for an automatic transmission when a clutch stroke sensor fails. The apparatus includes a clutch actuator for controlling a clutch stroke, a plurality of solenoid valves for controlling the clutch actuator, a clutch stroke sensor for measuring the clutch stroke, a control unit for feeding back a stroke signal detected by the clutch stroke sensor when requests for clutch engagement or disengagement are received and for controlling the solenoid valves so as to obtain a clutch moving speed defined by an engine rotational speed and other driving conditions. The control unit further includes a clutch engagement control section and a clutch disengagement control section for controlling solenoid valves for operating the clutch independently of the stroke signal when the stroke sensor fails.

Abstract: A failure diagnostic processing system including a checking element for achieving a diagnostic check with respect to sensors to produce first and second diagnostic signals regarding each sensor. The first and second diagnostic signals indicate whether or not a failure condition stands, respectively. Also included are counting element for achieving a count up and a count down selectively in response to the first and second diagnostic signals, respectively; an alarm element for providing an alarm indication in accordance with the count number of the counting element; and a recording element for creating a history of failure by recording the count number of the counting element where the count number exceeds a predetermined reference number for starting the record.