Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, estimates of engine fuel consumption for operating the engine with a plurality of cylinder modes or patterns while a transmission is engaged in different gears are determined and are used as a basis for deactivating engine cylinders.

A starting assistance method and device for an internal combustion engine supplied with a fuel that may contain ethanol, and including a fluid connection pipe between an intake manifold and a braking assistance device. The method including determining the engine temperature, determining the outdoor air temperature, blocking the pipe between the intake manifold and the braking assistance device for a given duration during a phase of starting the engine when the temperature of the engine is lower than a first threshold value and the outdoor air temperature is lower than a second threshold value, and freeing the pipe between the intake manifold and the braking assistance device when the engine is rotating autonomously.

Methods and systems are provided for taking mitigating action where a canister purge valve configured to control an amount of fuel vapors inducted into the engine during purging operations of a fuel vapor storage canister, is indicated as being degraded. In one example, a method comprises controlling an amount of pressure directed to a fuel tank and the fuel vapor storage canister via a pump positioned downstream of the fuel tank and canister to actively route fuel vapors to the canister during a refueling event. In this way, fuel vapors may be prevented from being routed to engine intake under conditions of a degraded canister purge valve, which may reduce opportunity for vehicle stall, improve driveability, and which may reduce release of undesired evaporative emissions to atmosphere.

Methods and systems are provided for controlling and coordinating control of a post-catalyst exhaust throttle and an EGR valve to expedite catalyst heating. By closing both valves during an engine cold start, an elevated exhaust backpressure and increased heat rejection at an EGR cooler can be synergistically used to warm each of an engine and an exhaust catalyst. The valves may also be controlled to vary an amount of exhaust flowing through an exhaust venturi so as to meet engine vacuum needs while providing a desired amount of engine EGR.

Methods and systems are provided for increasing an efficiency of a purging operation of a fuel vapor storage canister of a vehicle, the fuel vapor storage canister configured to capture and store fuel vapors stemming from a fuel tank of the vehicle. As one example, a method comprises reactivating one or more cylinders of an engine during a purging operation, in response to an indication that the purging of stored fuel vapors from the fuel vapor storage canister is compromised as a result of fuel vaporization stemming from the fuel tank. In this way, the canister may be effectively cleaned even under high fuel vaporization circumstances, which may improve fuel economy and may reduce release of undesired evaporative emissions to atmosphere.

When atmospheric pressure (Pa) which varies according to altitude is higher than a predetermined pressure threshold (Path) during idle operation in which catalyst warm-up request is issued, an intake pressure is controlled, through a throttle valve (19), to an intake pressure at which an intake air amount required to promote the warm-up of a catalyst converter (26) is obtained. When the atmospheric pressure (Pa) is lower than the predetermined pressure threshold (Path), the intake pressure is controlled, through a throttle valve (19), to an intake pressure (PaPb) at which a differential pressure (Pb) required by a brake booster (8) is obtained. Accordingly, negative pressure in the brake booster (8) can be secured while promoting the warm-up of the catalyst during the idle operation.

Methods and systems for providing vacuum to a vehicle are described. In one example, a method adjusts an engine air-fuel ratio in response to provide additional vacuum to the vehicle.

A method of controlling vacuum pressure for vehicle braking may include checking whether a vehicle is idle or enters a deceleration state, comparing an engine vacuum pressure and a booster vacuum pressure of the vehicle with a preset reference value, checking whether a valve control system of the vehicle is operable when the engine vacuum pressure and the booster vacuum pressure are lower less than the preset reference value, controlling the valve control system when the valve control system is operable; and controlling an air conditioner (A/C) or an alternator of the vehicle when the valve control system is inoperable.

Techniques for controlling a forced-induction engine having a low pressure cooled exhaust gas recirculation (LPCEGR) system comprise determining a target boost device inlet pressure for each of one or more systems that could require a boost device inlet pressure change as part of their operation and boost device inlet pressure hardware limits for a set of components in the induction system, determining a final target boost device inlet pressure based on the determined sets of target boost device inlet pressures and boost device inlet pressure hardware limits, and controlling a differential pressure (dP) valve based on the final target boost device inlet pressure to balance (i) competing boost device inlet pressure targets of the one or more systems and (ii) the set of boost device inlet pressure hardware limits in order to optimize engine performance and prevent component damage.

This blow-by gas recirculation device for an internal combustion engine is provided with a vacuum pump which supplies negative pressure to a brake booster and usable for recirculation of blow-by gas to an intake passage. This device includes: a PCV device for recirculating blow-by gas in a crankcase to the intake passage; a ventilation shortage region determination unit which determines whether or not an operational region of the engine is a PCV ventilation flow rate shortage region; and a brake negative pressure determination unit which determines whether or not the negative pressure of the brake booster is secured. The vacuum pump ventilates blow-by gas in the crankcase only when the determination units determines that the operational region is the PCV ventilation flow rate shortage region and that the negative pressure is secured. This reduces a contact risk of blow-by gas with engine oil, and inhibits the degradation of the oil.