Abstract: A fuel-pressure-sensor diagnosis device is applied to a fuel injection system having a plurality of fuel pressure sensors detecting a fuel pressure which is provided to a fuel injector of each cylinder, and a control portion controlling the fuel injectors by using a computed result which is computed based on a variation in the fuel pressure detected by the fuel pressure sensor due to a fuel injection. Two pressure sensors of which pulsation values of the detected fuel pressure are in a specified range are selected among the multiple fuel pressure sensors. For example, a pair “A” refers to the sensors #1 and #3, a pair “B” refers to the sensors #3 and #4, a pair “C” refers to the sensors #4 and #2, and a pair “D” refers to the sensors #2 and #1. An ECU diagnoses whether the selected sensors are faulty by comparing the detected values.

Abstract: A suspension control system for an automotive vehicle is provided which is operable to control transmission of vibratory energy from a road surface to a vehicle body. This suspension control system includes a variable damping force shock absorber, a vertical speed sensor which detects vertical speed of the vehicle body, a relative displacement speed sensor which detects the relative displacement between the vehicle body and a road wheel, and a damping force control unit which is operable to modify a damping force of the variable damping force shock absorber over a range from preselected maximum to minimum values based on the vertical speed and the relative displacement speed.

Abstract: A shock absorber damping force control system for a vehicle employs at least a high-frequency component included in sprung mass vibration as a factor to control a damping force of a shock absorber. The system provides a lower damping force of the shock absorber with a larger magnitude of the high-frequency component when signs of a sprung mass velocity and a relative velocity between a sprung mass and an unsprung mass coincide with each other. A low-frequency component may also be employed as a factor to control the damping force of the shock absorber. The system provides a lower damping force with a larger ratio of the high-frequency component relative to the low-frequency component when signs of the sprung mass velocity and the relative velocity coincide with each other.