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Evap Dual Path Purge Check Valve Monitor with Induced Boost Mode

IP.com Disclosure Number: IPCOM000249035D
Publication Date: 2017-Jan-27
Document File: 1 page(s) / 203K

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The IP.com Prior Art Database

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Evap Dual Path Purge Check Valve Monitor with Induced Boost Mode

Gasoline Turbo Direct Injection (“GTDI”) engines must purge under vacuum or boost conditions. To

facilitate purge under boost, new hardware is needed (check valves and ejector). CARB mandates that

the entire Evap system up to the CPV be leak checked. At the same time, all Evap components must be

tested for functionality. As the GTDI check valve diagnostic is performed under boost mode, it is difficult

to attain even a 10% completion if the drive cycle is light natured and does not involve heavy loads such

as going uphill, towing, heavy payload, aggressive drive behavior. Most drive cycles are under natural

aspiration mode. There is not much opportunity to diagnose the check valves under a light load drive

cycle. Lack of check valve monitor execution leads to low execution rates.


In Autonomous (“AV “) or driverless cars, a unique opportunity presents itself. The method artificially

and intentionally “loads” the engine as much as possible for the sake of inducing boost mode and

enticing the diagnostic to execute.For instance: 1) The A/C is turned on to load the engine, 2) The major

electrical loads (headlights, defroster, stereo, cabin blower at high speed, engine cooling fans, wiper

motors, heated seats…) are turned on to make alternator load higher to the engine, 3) The transmission

shift schedule is altered such that the higher gears are engaged sooner in time and the torque convertor

is locked. This m...