| 摘要 |
A system and method for detecting engine malfunctions based on crankcase pressure include determining a reference value indicative of current engine operating conditions and using the reference value to determine a crankcase pressure limit which varies as a function of the reference value. The sensed crankcase pressure is compared to the limit to determine when a fault condition exists. The reference value is preferably a function of engine speed and requested engine torque and includes a second order term multiplied by a calibratable constant which controls sensitivity of the fault determination. The sensitivity may be adjusted to provide equally detectable faults across all engine speeds and loads, to be more sensitive to faults occurring at higher engine speeds, or to be more sensitive to faults occurring at higher engine loads. The system and method control the engine based on the determination of an engine fault. Subsequent control may include alerting the vehicle operator, reducing available engine torque, stopping the engine and/or logging a fault for subsequent service or maintenance. Early cylinder/piston fault detection provides more time for the vehicle operator and/or the engine controller to take remedial actions to prevent more serious engine damage. |
