Control apparatus with fail-safe faculty

Abstract

In a control apparatus with fail-safe faculty for controlling an output torque of a vehicle including an electronically controlled fuel-injection type engine and an automatic transmission having a torque converter and a speed change gear mechanism, in which when an abnormal start operation causing a racing select shock is detected, an output torque of the engine is reduced by stopping a supply of a fuel to all or half cylinders of the engine in dependent upon the engine running speed, a clutch transfer torque capacity is reduced by reducing a line pressure of the speed change gear mechanism, and a gear position of the speed change gear mechanism is shifted into a second gear position, the improvements being characterized in that when a system failure in which one of sensors and actuators becomes out of order or a communication line between an engine control computer and a transmission control computer becomes out of order occurs, the reduction of the engine output torque is performed upon the abnormal start operation without fail. Further, one of the reduction of the clutch transfer torque capacity and the shift of the gear position into the second gear position, which may be conducted without being affected by the system failure is performed. In a preferable embodiment, upon the system failure, the fuel supply to a larger number of cylinders is stopped, the clutch transfer torque capacity is reduced to a larger extent and the gear position is shifted into a third gear position in response to the abnormal start operation.