Methods and systems are provided for determining engine knock sensor degradation. In one example, a method may include sending an excitation signal to an actuator to generate vibrations in the absence of engine combustion, and determining engine knock sensor degradation by comparing the knock sensor output with the excitation signal.

Various embodiments include a method for monitoring a pressure sensor in a hydraulic system of a motor vehicle, the method comprising: actuating a valve of a pressure accumulator in the hydraulic system; detecting a behavior of the actuated valve in response to the actuation; determining a time offset of the actuated valve based on the detected behaviour; determining a measurement value of the pressure sensor; comparing the time offset of the valve with the determined measurement value; and checking a plausibility of the measurement value based on the comparison.

An electrode pair that forms a pressure-sensitive capacitance Cx in the central portion of a diaphragm is called a first electrode pair (pressure-sensing electrode pair), and another electrode pair that forms a reference capacitance Cr in the circumferential portion of the diaphragm is called a second electrode pair (reference electrode pair). The ratio Cx/Cr of a change Cx in the pressure-sensitive capacitance Cx, which is obtained from the pressure-sensing electrode pair at the time of evacuation, to a change Cr in the reference capacitance Cr, which is obtained from the reference electrode pair at the time of evacuation, is calculated as an index for malfunction detection . Then, the index for malfunction detection thus calculated is compared with the reference value ref, which represents the index observed during normal operation, and whether deformation due to a cause other than pressure has been generated in the diaphragm is determined.

An external impact avoiding part makes a sensor failure detection part withhold from determining that a right or left door pressure sensor has failed when a right-left detection difference calculated at first time is a threshold value or larger, and makes a detection value comparison part calculate the right-left detection difference again after a calming time has elapsed. An effect of closing operation of a right door on the right door pressure sensor or an effect of closing operation of a left door on the left door pressure sensor reduces during the calming time. The avoiding part subsequently makes the detection part compare the right-left detection difference calculated again with the threshold value. As a result of the comparison, when the right-left detection difference is the threshold value or larger, the avoiding part makes the detection part determine that the right or left door pressure sensor has failed.

A microelectromechanical pressure sensor includes a monolithic body of semiconductor material having a front surface. A sensing structure is integrated in the monolithic body and has a buried cavity completely contained within the monolithic body at the front surface. A sensing membrane is suspended above the buried cavity and is formed by a surface portion of the monolithic body. Sensing elements of a piezoresistive type are arranged in the sensing membrane to detect a deformation of the sensing membrane as a result of a pressure. The pressure sensor is further provided with a self-test structure integrated within the monolithic body to cause application of a testing deformation of the sensing membrane in order to verify proper operation of the sensing structure.

A diagnostic system of a vehicle includes an energy absorber sandwiched between a front bumper fascia and a front bumper reinforcement of the vehicle. A sensing tube is located between a portion of the energy absorber and the front bumper reinforcement. A first pressure sensor and a second pressure sensor measure a first pressure of air and a second pressure of air within the sensing tube, respectively. An actuator is configured to actuate and vary a pressure within the sensing tube. A diagnostic module is configured to selectively diagnose the presence of a fault with the sensing tube based on at least one of: a first change in the first pressure in response to actuation of the actuator; and a second change in the second pressure in response to the actuation of the actuator.

An apparatus for diagnosing a failure of a sensor may include an engine; an intake manifold; a turbocharger including a turbine rotated by exhaust gas of the combustion chamber and a compressor provided at the intake line, rotated in connection with the turbine, and compressing external air; a map sensor measuring a pressure of a front end portion of the compressor; a differential pressure sensor measuring a differential pressure of front and rear end portions of an EGR valve provided at an EGR apparatus; an operation information detecting device measuring operation information including an engine speed and a load; and a controller determining whether an exhaust gas pressure is constant from the operation information and comparing a change amount of the differential pressure sensor signal and a change amount of the map sensor signal in the condition that the exhaust gas pressure is constant to diagnose a failure of the differential pressure sensor.

A readout circuit for use with a Wheatstone bridge sensor. At least some of the example embodiments are methods including: driving an excitation signal in parallel through a first set of sensor elements of a Wheatstone bridge sensor and refraining from driving the excitation signal through a second set of sensor elements of the Wheatstone bridge sensor; measuring response of the first set of sensor elements, the measuring response of the first set of sensor elements creates a first measurement; and then driving the excitation signal in parallel through the second set of sensor elements of the Wheatstone bridge and refraining from driving the excitation signal through the first set of sensor elements; and measuring response of the second set of sensor elements, the measuring response of the second set of sensor elements creates a second measurement.

A pressure measuring arrangement is proposed. The pressure measuring arrangement includes a first MEMS pressure sensor arranged on a carrier, and also a second MEMS pressure sensor arranged on the carrier. Furthermore, the pressure measuring arrangement includes an integrated circuit arranged on the carrier, the integrated circuit being coupled to the first MEMS pressure sensor and the second MEMS pressure sensor.

Methods and systems are presented for diagnosing operation of a fuel tank pressure sensor. The methods and systems may include releasing fuel vapors from a fuel tank to an engine when an engine is rotating in a fuel cut out mode while a catalyst temperature is greater than a threshold temperature to determine whether or not the fuel tank pressure sensor is degraded.