Methods and systems for provided for accurately estimating an engine intake or exhaust manifold pressure using a laser pressure transducer. Laser circuitry is coupled to a pressure sensitive diaphragm that is mounted to the engine manifold. Manifold pressure is inferred based on a deflection of the diaphragm, as estimated based on a timing between emission of a laser pulse into the diaphragm and detection of a reflected pulse from the diaphragm.

A method is presented for diagnosing a particulate matter sensing system, where the system includes a sensing element having two electrodes spaced from one another. The method determining at a first time during a cool-down event a first sensing element temperature and a resistance of the sensing element, and determining at a later second time during the cool-down event a second sensing element temperature and the resistance of the sensing element. The method further includes calculating a predicted sensing element resistance at the second sensing element temperature, based on the first sensing element temperature, the resistance of the sensing element determined at the first time, and a predetermined model of the resistance vs. temperature characteristics of the sensing element. A fault condition for the system may be indicated based on a comparison of the predicted sensing element resistance at the second sensing element temperature and a measured sensing element resistance.

Methods and systems are provided for detecting NOx sensor degradation based on results from a NOx sensor self-diagnostic (SD) test. In one example, a method may comprise: determining that a nitrogen oxide (NOx) sensor is degraded if outputs received from the sensor via a CAN bus during a self-diagnostic test are outside a threshold range. Additionally, only outputs received from the sensor during a self-diagnostic (SD) test performed after a first completed SD test after a key-off event, where the outputs are generated under conditions where a temperature at the sensor is less than a threshold, and an oxygen concentration is within a threshold range may be used to determine if the sensor is degraded.

A fuel vapor system for a vehicle includes a fuel vapor canister that traps fuel vapor from a fuel tank of the vehicle. A purge valve opens to allow fuel vapor flow to an intake system of an engine and closes to prevent fuel vapor flow to the intake system of the engine. An electrical pump pumps fuel vapor from the fuel vapor canister to the purge valve. A diagnostic module (a) selectively diagnoses a fault in the fuel vapor system based on at least one of: (i) a speed of the electrical pump measured using a pump speed sensor; and (ii) a pressure at a location between the electrical pump and the purge valve, and (b) illuminates a malfunction indicator lamp (MIL) within a passenger cabin of the vehicle when the fault is diagnosed.

Systems and methods for detecting and compensating miswiring of oxygen sensors of a cylinder bank of an engine are disclosed. In one example, fuel control parameters are monitored to determine whether or not the fuel control parameters diverge to fuel control thresholds. If so, a controller may switch which cylinder's equivalence ratios are adjusted in response to output of a particular oxygen sensor.

A method executed by at least one server, comprising: receiving, from a first monitored system comprising an internal combustion engine and a first sensor, a first signal associated with a first occurrence and a second occurrence of an internal combustion engine event and first measurement data of the first sensor; determining a first measurement from the first measurement data and a second measurement from the first measurement data based on the first and second occurrences, respectively; determining a reference measurement; determining a first reference deviation; determining a second reference deviation; after determining the first reference deviation is less than a first reference threshold and the second reference deviation is less than a second reference threshold, determining a measurement deviation; comparing the measurement deviation to a measurement threshold; and after determining the measurement deviation satisfies the measurement threshold, determining a first exhibited useful life of the first sensor.

The invention relates to a method for operating an internal combustion engine, in which the internal combustion engine has at least one first combustion chamber, in which combustion processes take place during fired operation of the first combustion chamber, at least one second combustion chamber, in which combustion processes take place during a fired operation of the second combustion chamber, a first knock sensor assigned to the first combustion chamber, by means of which irregular combustions in the first combustion chamber can be detected, and a second knock sensor assigned to the second combustion chamber, by means of which irregular combustions in the second combustion chamber can be detected. The internal combustion engine is operated in a first operating state in which channel switching is carried out. A switch is made from the first operating state to a second operating state in which channel switching does not take place.

A negative pressure detection part detects a negative pressure from a signal of a negative pressure sensor detecting a negative pressure generated due to rotation of an internal combustion engine. The negative pressure is used to assist a vehicle driver's braking operation. An abnormality determination part determines, during continuation of the internal combustion engine stopped state, that the negative pressure sensor is in an abnormal condition if the detected negative pressure is out of a normal range near an atmospheric pressure to a vacuum pressure side when an operation of decreasing the negative pressure is performed on a brake pedal greater than or equal to a predetermined number of times or greater than or equal to a predetermined period of time or when a total operation amount of the decreasing operation is greater than or equal to a predetermined amount.

An internal combustion engine includes a port injection valve and a feed pump that pressurizes the fuel. An engine ECU performs a stuck abnormality diagnosis of the fuel pressure sensor based on detection values of the fuel pressure sensor in first processing and second processing. The first processing includes setting a target pressure of the fuel in the storage section to a first pressure, and detecting a pressure of the fuel with the fuel pressure sensor. The second processing includes setting the target pressure of the fuel in a low-pressure delivery pipe to a second pressure lower than the first pressure, and detecting a pressure of the fuel. The engine ECU causes the first processing to be performed in response to a start signal that starts an internal combustion engine, and causes the second processing to be performed subsequent to the first processing.

A signal from a linear lambda probe, which signal is meant to represent an air/fuel ratio for the gas flowing in the exhaust section, specifically prior to combustion of said gas, is determined based on a pump current. A difference signal is formed based on a difference between a pump voltage signal and a Nernst voltage signal. An offset error in the measured signal is determined based on the difference signal for an approximately stoichiometrically prescribed raw setpoint value for the air/fuel ratio, with a setpoint value for the air/fuel ratio being determined based on the raw setpoint value and a forced excitation signal.