Abstract: A failure detecting method and apparatus for an automatic transmission of a vehicle having a vehicle speed sensor mounted on said vehicle for sensing a vehicle speed and an inhibitor switch attached on said automatic transmission for detecting a gear shift range position, The method is carried out by judging whether the vehicle speed is larger than a predetermined value; checking whether a neutral range position is detected; detecting whether another gear shift range position is absent after a predetermined time has lapsed; and then controlling the automatic transmission as if the gear shift range position is in a drive range. This enables one to precisely detect a failure of the range signal line and to control the automatic transmission in an optimum condition under any driving conditions.

Abstract: A sensor failure and erroneous signal detection system for use in automobiles equipped with cruise control. This system prevents cruise control from operating if certain predetermined conditions occur. Further, the system will determine if the cruise control signal has been erroneously generated and set up an error "flag". A failure is determined in the cruise control system if either one of the following conditions is present when a cruise control signal is generated: (1) the vehicle is traveling below a predetermined speed; (2) the brake switch is on; (2) the shift range is in "N", "R" or "P"; or (4) either (1), (2) or (3) continues for a predetermined period of time. Upon occurrence of (1), (2), (3), or (4), an error has been detected and the automatic transmission is instructed to return to normal operation.

Abstract: A method and system for detecting a failure of an automatic transmission for a vehicle employing a speed shift range switch operation signal from a speed shift range switch as one of the control signals to control the automatic transmission. The method is carried out by: detecting a speed shift range from the speed shift range switch; generating a start signal indicating a starting state of a starter for expediting a start of an engine for the vehicle; and automatically controlling the automatic transmission so as to maintain the speed shift range in the case where "P" or "N" range is not detected when the start signal is "ON".

Abstract: In case where an engine rotational detection signal from an ignition pulse generator is not appropriately detected even if an amount of induction air and a fuel injection amount are larger than predetermined values, an engine rotational signal failure is decided, and an automatic transmission is controlled in a state before the decision. Therefore, the automatic transmission control based on the engine rotational speed such as, for example, a speed shift control (ordinarily a shift control), a lockup control (ordinarily a lockup control, a smooth control), a line pressure control (ordinarily a line pressure control, a starting time control) can be appropriately controlled. Thus, the automatic transmission control can be executed based on the engine rotational speed.

Abstract: A failure detecting system for an automatic transmission of a vehicle is disclosed. The system can be controlled by the engine rotation speed, cruise control signal, a brake signal from a brake switch, or a shift range switch operation signal from a shift range switch.

Abstract: A multiple disk clutch is provided for a rear wheel differential of a vehicle. A restricting torque for the clutch is set by vehicle speed, longitudinal acceleration and lateral acceleration of the vehicle. A large steering angle at a low vehicle speed is detected in accordance with the vehicle speed and a steering angle. In response to the restricting torque and a detected large steering angle at a low vehicle speed, the clutch is operated to reduce a restricting operation for the clutch.

Abstract: An ideal lateral acceleration is calculated based on vehicle speed and steering angle, and an actual lateral acceleration is calculated based on a lateral acceleration detected by a lateral G sensor. A breakaway point of tires is determined by comparing the actual lateral acceleration with the ideal lateral acceleration. A differential operation of a central differential is controlled by restricting the differential operation in accordance with a determined breakaway point and the difference between the ideal lateral acceleration and the actual lateral acceleration.