摘要:
Methods and systems are provided for using a crankcase vent tube pressure or flow sensor for diagnosing a location and nature of crankcase system integrity breach. The same sensor can also be used for diagnosing air filter plugging and PCV valve degradation. Use of an existing sensor to diagnose multiple engine components provides cost reduction and sensor compaction benefits.
摘要:
A method for controlling transitions between activating and deactivating a vehicle air conditioner compressor is disclosed. In one example, displacement of the air conditioner compressor is adjusted before the air conditioner is coupled to an energy conversion device. The method may provide smooth transitions between different air conditioner compressor control modes.
摘要:
Systems and methods for monitoring crankcase ventilation system integrity are disclosed. In one example approach, a method comprises indicating a crankcase ventilation system degradation based on a lower vacuum than expected downstream of a PCV breather tube. For example, indicating a crankcase ventilation system degradation based on a lower vacuum than expected downstream of a PCV breather tube may include indicating a crankcase ventilation system degradation based on an absolute pressure sensor measurement relative to a gauge pressure sensor measurement.
摘要:
Methods and systems are provided for monitoring cylinder valve deactivation in an engine operating with a plurality of cylinder valves. One example method comprises indicating valve degradation based on an indication of manifold pressure over a plurality of immediately successive induction events of the engine, the indication responsive to increases and decreases in the indication of manifold pressure correlated to the induction events of engine cylinders and further correlated to whether cylinders are commanded to be activated or deactivated.
摘要:
Methods and systems are provided for identifying and differentiating knock and pre-ignition using a plurality of knock sensors distributed along an engine block. By dynamically adjusting cylinder-specific assignment of the knock sensors for knock detection and pre-ignition detection based on operating conditions of each cylinder, knock and pre-ignition is more reliably identified and distinguished.
摘要:
Systems and methods for monitoring cylinder air/fuel imbalances are provided. In one example approach, a method comprises, identifying a cylinder with a potential air/fuel imbalance based on crankshaft accelerations generated by a series of rich, lean, and stoichiometric conditions in the cylinder while keeping the engine at stoichiometry.
摘要:
Methods and systems are provided for mitigating engine pre-ignition based on a feed-forward likelihood of pre-ignition and feedback from a pre-ignition event. In response to an indication of pre-ignition, a cylinder may be enriched while an engine load is limited. The enrichment may be followed by an enleanment to restore exhaust catalyst feed-gas oxygen levels. The mitigating steps may be adjusted based on engine operating conditions, a pre-ignition count, as well as the nature of the pre-ignition.
摘要:
Methods and systems are provided for controlling a vehicle engine, the engine including a turbocharger and a transmission. One example method comprises, operating the transmission at a first lower gear with a first boost level, increasing the boost from the first boost level before completing a shift from the first lower gear to a second higher gear, and after completing the shift, operating the transmission at the second higher gear with the increased boost.
摘要:
An engine system for a vehicle and its method of operation are provided. In one embodiment, a control system is configured to indicate a clogging of a fuel filter based on a period of time that a fuel pressure switch remains in a low pressure state. In some embodiments, the control system may respond to an indicated clogging of the fuel system by limiting one or more of fuel pressure, fuel flow rate, and vehicle speed. By limiting the flow rate and/or the pressure at which fuel is delivered to the engine during conditions when the low pressure fuel sub-system is unable to provide sufficient fuel pressure and/or flow, degradation and/or damage to the fuel system, including the high pressure pump, may be reduced or eliminated.
摘要:
A method for controlling torque of an air conditioner compressor is disclosed. In one example, the air conditioner compressor is a variable displacement compressor. The method may provide smooth transitions between different air conditioner compressor torques.