Abstract: A braking system 12 for use with an electric vehicle 10 including an electric motor/generator assembly 14, and a conventional electrical energy storage device 16. Motor/generator 14 selectively drives wheels 20 of vehicle 12. The braking system 12 includes a motor control module 26 which is communicatively coupled to motor/generator 14 and which selectively causes motor/generator 14 to provide a regenerative braking function at wheels 20 of vehicle 10. Braking system 10 further includes an antiskid braking system which selectively provides friction braking at wheels 20 and 24 of vehicle 10. The braking system 12 is effective to detect antiskid braking events at each of the wheels 20, 24, to selectively provide an antiskid braking function at each of wheels 20, 24 where the antiskid braking events are detected, and to selectively disable the regenerative braking function only when an antiskid braking event is detected at either of wheels 20.

Abstract: A method and system that responds to non-propulsive needs of a hybrid vehicle by setting at least two thresholds related to engine support: one threshold to keep a running engine ON and a another threshold to turn the engine ON from an OFF state.

Abstract: A system or method for compensating for low vacuum levels in a brake-by-wire system includes continually monitoring the level of vacuum in a vacuum booster. The state or condition of the vacuum source is also monitored to determine whether it is on or off. When the vacuum source is off, the level of vacuum is measured to determine whether it is at or below a critical level. If the level of vacuum is critically low, the vacuum source is turned on. If the vacuum level is not critically low, the hydraulic boost gain is modified in order to provide more braking pressure in response to brake force exerted at the brake pedal.

Abstract: A method is presented for controlling fuel tank pressure in an internal combustion engine. The engine, the fuel tank and the carbon canister are connected in a three-way connection. The engine can be selectively isolated by a purge control valve, and the fuel tank can be selectively isolated by a fuel tank control valve. The operation of both valves is coordinated by an electronic engine controller. By isolating the fuel tank during the carbon canister purge, better estimate of the fuel fraction flowing into the engine can be achieved, thereby improving fuel economy.

Abstract: A method is presented for controlling fuel tank pressure in an internal combustion engine. The engine, the fuel tank and the carbon canister are connected in a three-way connection. The engine can be selectively isolated by a purge control valve, and the fuel tank can be selectively isolated by a fuel tank control valve. The operation of both valves is coordinated by an electronic engine controller. By isolating the fuel tank during the carbon canister purge, vapor spikes into the engine are eliminated, thus preventing engine stalls. Also, canister durability is improved by continuously storing and purging vapors in opposite directions.

Abstract: A method is presented for diagnosing a condition in the fuel vapor purge system. The engine, the fuel tank and the carbon canister are connected in a three-way connection. The engine can be selectively isolated by a purge control valve, and the fuel tank can be selectively isolated by a fuel tank control valve. The operation of both valves is coordinated by an electronic engine controller. By isolating the fuel tank, and comparing the actual rate of change of the internal tank pressure (from the tank pressure sensor) to the estimated rate of change (from engine operating conditions) it is possible to determine if a condition occurred, and whether it is in the tank or in the vapor purge lines.

Abstract: An electric powered brake system (10) for braking road-engaging wheels of a motor vehicle. An ignition switch for turning a motor of the vehicle on and off also controls the application of electric power to the electric powered brake system. A control and method (FIGS. 2 and 3) for maintaining application of full electric power to the electric powered brake system when the ignition switch is operated from ON to OFF so long as at least one parameter (60, 62, 64, 66) related to a respective component of the vehicle and indicative of a need to maintain full electric power application to the brake system continues to exist and for discontinuing application of full electric power to the brake system when all of selected ones of several such parameters are indicative of lack of need to maintain full electric power application to the brake system.

Abstract: An electronic engine controller controls the catalytic converter temperature by generating a desired rich air/fuel ratio that will maintain the catalytic converter at a predetermined temperature. The actual air/fuel ratio is ramped to the desired air/fuel ratio at a first rate when the catalytic converter temperature is greater than a first predetermined temperature. The actual air/fuel ratio is ramped to the desired air/fuel ratio at a second rate when the catalytic converter temperature is greater than a second predetermined temperature but less than the first predetermined temperature.

Abstract: An engine diagnostic method for an engine having a switching exhaust gas sensor and a fuel system uses the switching exhaust gas sensor during open loop fuel enrichment to diagnose fuel system degradation, including fuel filter degradation.

Abstract: A tire monitoring and warning assembly 10 which monitors and measures attributes or characteristics of at least one of the selectively inflatable tires 14-20 of a vehicle 12 and which compares the obtained measurements with a stored value which represents a value of the attribute or characteristic occurring or existing when the at least one tire 14-20 is desirably inflated, and which, based upon the comparison, warns the driver if the at least one of the tires 14-20 is deflated.

Abstract: A method and system for reducing time required for a catalyst to reach optimum operating temperature control an air/fuel ratio based on the catalyst temperature to supply excess air to the catalyst during closed loop lambda control. A lambda bias or offset is varied as a function of the catalyst temperature, engine speed, and engine load to bias the air/fuel ratio lean of the stoichiometric ratio. Excess air may be supplied to the catalyst for a predetermined period after a cold engine start or at any time that the catalyst temperature is below its optimum operating temperature for efficient conversion. The bias or offset is reduced to zero after the catalyst reaches a desired operating temperature or the predetermined time period expires.

Abstract: An onboard diagnostic mechanism for a sealed vehicle fuel delivery system. By controlling fuel system valves, the electronic engine controller (EEC) periodically subjects the sealed system to an initial vacuum level, then monitors the pressure increase due to evaporative effects during a predetermined test interval. Excessive deviations in measured pressure compared to predetermined criteria produce indications of potential undesired operational conditions. To prevent fuel sloshing which results from aggressive driving or rough roads from producing false output indications, the instantaneous system pressure is compared with a rolling average of tank pressure to produce a difference signal indicative of fuel sloshing. If the resulting difference signal exceeds a predetermined threshold, the monitoring process is aborted in favor of a later test after the fuel sloshing condition terminates.

Abstract: A method and system for determining a level of vapor generated by an evaporative system. The evaporative system is closed to atmosphere. An initial pressure in a fluid-filled tank is sensed and, after a predetermined amount of time, a second pressure in the tank is sensed. A pressure difference is determined based on the sensed initial pressure and the sensed second pressure. The level of vapor generated by the evaporative system is determined based on the pressure difference.