An internal combustion engine of a hybrid drive vehicle includes an exhaust gas purification catalyst in an exhaust passage. An internal combustion engine control device is configured to continuously rotate the internal combustion engine for a predetermined time period after an engine start. The internal combustion engine control device prohibits a fuel-cut within the predetermined time period after the engine start, thereby suppressing the frequent repetition of the start and stop of the internal combustion engine due to an accelerator pedal operation and suppressing oxygen storage in the exhaust gas purification catalyst associated with the fuel-cut. As a result, exhaust gas purification performance at the time of restarting the internal combustion engine is ensured.

A method is presented, wherein a fuel vapor canister heating element is activated during a first condition, which includes an engine-off condition, and atmospheric air is directed through the fuel vapor canister and into an engine intake. Degradation of the fuel vapor canister heating element is indicated based on an output of an engine intake air temperature sensor. In this way, the integrity of the fuel vapor canister heating element can be determined without relying on canister temperature sensors, which may be confounded by the cooling of the fuel vapor canister during fuel vapor desorption.

Methods and systems are provided for dealing with a change of mind event during an automatic shut-down of an engine in which the speed at which a starter motor used to restart the engine is disengaged is based upon the comparison of current engine speed (N) with a cranking speed limit (S.sub.LIM). In one example, during an engine restart while the engine is spinning down, the starter motor may crank the engine to a threshold cranking engine speed adjusted based on a position of the gear.

A stop control circuit for controlling stopping of an engine that performs a rotational operation of an alternator that charges a power storage device, the stop control circuit including: an instruction unit configured to output a stop instruction signal for instructing stopping of the engine; and a first electronic control unit configured to output a stop signal for stopping rotation of the engine to the engine after a power storage amount of the power storage device reaches a predetermined value from when the stop instruction signal is received.

Methods and systems are provided for preheating a fuel vapor storage canister in an evaporative emissions system prior to a vehicle start. In one example, a method may include learning common vehicle routes and identifying routes in which fuel vapor storage canister preheating is indicated, such as routes that will enable fuel vapors to be purged to an engine intake shortly after the vehicle start. Then, in anticipation of an identified route for fuel vapor storage canister preheating, a vehicle controller may be transitioned from a sleep mode to an awake mode prior to the vehicle start in order to commence a fuel vapor storage canister preheating routine.

Methods and systems are provided for determining barometric pressure. In one example, an onboard vacuum pump is utilized to draw a vacuum at a constant flow rate across a reference orifice, and the resulting vacuum level is converted to a barometric pressure. In this way, other sensors for determining barometric pressure in a vehicle may be rationalized without the use of engine operation, and in an example where the other sensors for determining barometric pressure are not functioning as desired, barometric pressure as inferred from the onboard pump may be utilized to adjust engine operation.

A microchip oxygen sensor for sensing exhaust gases from a combustion process, and related methods. The microchip oxygen sensor includes a dielectric substrate and a heater pattern affixed to the substrate. A first electrode is affixed to the substrate and has a first plurality of fingers forming a first comb. A second electrode is affixed to the substrate and has a second plurality of fingers forming a second comb. The second electrode is disposed in spaced relation to the first electrode such that the first and second combs face each other. A semiconducting layer is disposed over the first and second electrodes so as form a physical semiconductor bridge between the first and second electrodes. The semiconducting layer comprises an n-type semiconducting material or a p-type semiconducting material. A porous dielectric protective layer, advantageously containing a catalytic precious metal, may cover the semiconducting layer.

A method is described for operating an electric fuel pump constituting a low-pressure pump in a fuel supply system for an internal combustion engine, having a high-pressure reservoir and a high-pressure pump, of a motor vehicle. The electric fuel pump is operated at least temporarily, during a time period during which the internal combustion engine is switched off during operation of the motor vehicle, with a minimum value for a control application variable for the electric fuel pump.

Methods and systems are provided for reducing accumulation of condensate in an engine intake during an engine non-combusting condition. In one example, during an engine non-combusting condition, responsive to a higher than threshold ambient humidity and a lower than threshold intake manifold temperature, intake and exhaust valves of deactivatable cylinders may be closed in order to seal the cylinders and during an immediately subsequent engine combusting condition, the intake and exhaust valves of the deactivatable cylinders may be activated and combustion may be resumed in the deactivatable cylinders before starting combustion in non-deactivatable cylinders. Also, during the engine non-combusting condition, residual hot exhaust may be recirculated to the intake manifold to evaporate condensate in the intake manifold.

An electronic control unit controls an air-fuel ratio sensor to detect an air-fuel ratio in an exhaust gas from an internal-combustion engine. An A/D converter and a sample value processor obtain a signal based on an impedance of the air-fuel ratio sensor in response to a power supply to the air-fuel ratio sensor via filters. A microcomputer determines an environment temperature of the air-fuel ratio sensor based on the signal. A switch or the microcomputer switches between an upstream side voltage supply path and a downstream side voltage supply path to obtain a signal depending on whether the air-fuel ratio sensor is operating in a low-temperature environment to improve the accuracy of the obtained signal.