A lawn care device may include an engine to selectively power the lawn care device, a frame supporting the engine of the lawn care device, an ignition system for selectively powering the lawn care device based at least in part on operation of an ignition interface controlled by a processor (310), an optical isolator (320) which detect the operational presence of the processor (310) and a shutdown circuit (300) which is able to ground out the ignition coil (360) as a function of the conductive state of the optical isolator (320); the shutdown circuit being powered by an ignition coil (360) of the ignition system to generate a failsafe condition in response to failure or loss of the processor (310).

Methods and systems are provided for diagnosing a humidity sensor positioned in an intake system of a vehicle engine system. In one example, a method comprises rotating an engine unfueled in reverse and injecting a fluid into an exhaust system of the engine system, to draw the fluid into the intake system, where a humidity sensor output signal greater than a baseline output signal by a predetermined threshold is indicative of a humidity sensor that is functioning as desired. In this way, a humidity sensor may be periodically rationalized which may prolong engine lifetime by ensuring the engine is operating at optimal parameters.

Methods and systems are provided for a diagnostic of a humidity sensor positioned in an intake of an engine and adjusting engine operation responsive to findings of the diagnostic. In one example, the method may include sealing a vehicle exhaust system of an engine, combusting fuel at cylinders of the engine while flowing gases through the engine in a first direction, and then, flowing the combusted exhaust gases through the engine in a reverse, second direction to the humidity sensor positioned in the intake. The method may further include indicating degradation of the humidity sensor based on the output of the humidity sensor while flowing gases in the first and second directions.

A method for operating a rotation separator in an internal combustion engine, wherein, after the engine and separator have been switched off, it is determined whether there is a danger of the condensate in the separator freezing to ice because of cold ambient temperatures. If there is danger of ice formation, the separator is started up again by itself, i.e., without the engine being re-started, and is operated at a speed that effectively removes condensate from the rotor of the separator, so as to prevent icing of the separator.

Methods and systems are provided for determining whether an exhaust gas recirculation (EGR) valve is degraded and being held open in a vehicle system. In one example, a method may include, in response to an engine pull-down request, closing a throttle coupled to an intake manifold of the engine, closing the EGR valve, propelling the vehicle via an electric motor, and checking operation of the EGR valve based on both intake manifold pressure and exhaust pressure. For example, if the intake manifold pressure does not decrease by a threshold amount relative to the exhaust pressure, EGR valve degradation may be indicated.

A control apparatus controls the operation of a starter such that, after an idling stop is executed and before a request for starting an engine is subsequently issued, the control apparatus executes a preset which causes a pinion to engage a ring gear. A control apparatus controls the operation of a starter such that, after an idling stop is executed and before a request for starting an engine is subsequently issued, the control apparatus executes a preset which causes a pinion to engage a ring gear. It is determined that the preset condition has been cancelled, and the preset is again executed. In that case, the pinion is already engaged with the ring gear at the time point when a request for starting the engine is issued. In that way it is unnecessary for the control apparatus to push out the pinion after a start request is issued.

Methods and systems are provided for diagnostics of a cylinder valve actuation mechanism in a variable displacement engine (VDE). In one example, during an engine-off condition, the engine may be rotated unfueled, via a starter motor, and a reference exhaust air flow may be estimated. One or more deactivatable engine cylinders may then be deactivated and degradation of the cylinder valve actuation mechanism may be indicated based on a difference between the exhaust air flow following the cylinder deactivation and the reference exhaust air flow.

Methods and systems are provided for diagnosing a humidity sensor positioned in an intake system of a vehicle engine system. In one example, a method comprises rotating an engine unfueled in reverse and injecting a fluid into an exhaust system of the engine system, to draw the fluid into the intake system, where a humidity sensor output signal greater than a baseline output signal by a predetermined threshold is indicative of a humidity sensor that is functioning as desired. In this way, a humidity sensor may be periodically rationalized which may prolong engine lifetime by ensuring the engine is operating at optimal parameters.

A vehicle control apparatus includes a current sensor that detects a current value of a battery; and a processing device that suppresses initiation of idling stop control in a vehicle non-stop state with a vehicle speed higher than 0, in the case where an abnormal state of the battery is detected based on an output signal of the current sensor in the vehicle non-stop state.

There is provided a hybrid vehicle comprising a mode selection device configured to select one drive mode among a plurality of drive modes according to a user's operation. The plurality of drive modes include a first drive mode in which the hybrid vehicle is driven with power from a motor with stopping rotation of an engine and a second drive mode in which the hybrid vehicle is driven with rotation of the engine. On satisfaction of filter regeneration conditions that an accumulated amount of particulate matter accumulated on a filter is equal to or greater than a predetermined accumulated amount and that a temperature of the filter is equal to or higher than a predetermined temperature, the hybrid vehicle is driven in the second drive mode even when the first drive mode is selected by the mode selection device.