Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

METHOD TO MEASURE CARBON CANISTER RESTRICTION IN A PHEV VEHICLE

IP.com Disclosure Number: IPCOM000229428D
Publication Date: 2013-Jul-29
Document File: 1 page(s) / 222K

Publishing Venue

The IP.com Prior Art Database

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 68% of the total text.

Page 01 of 1

METHOD TO MEASURE CARBON CANISTER RESTRICTION IN A PHEV VEHICLE

PHEV vehicles typically contain sealed fuel tanks due to limited engine run time. With limited engine run time, canister cant be purged. An FTIV valve shown below is used to seal the fuel tank. Running loss and diurnal vapors are thus trapped inside the tank. Only refueling vapors are adsorbed inside the canister. Canisters have inherent restriction due to compaction of tiny activated carbon pellets inside them. As the canister is subjected to real life testing, this restriction increases as dirt, dust, liquid carryover fuel and other contaminants make their way inside the canister. One telltale that canister is restricted is the inability to refuel. With high enough restriction, the canister back pressure will cause the refueling pump to shut off. Premature shutoffs currently have no diagnostics and it is a cumbersome task for technicians to troubleshoot. Currently there is no diagnostic to measure canister restriction.

Method

The method takes advantage of the fuel tank being sealed and uses engine vacuum to flow the canister to measure its restriction. The CPV valve is opened at 100% during high manifold vacuum, preferably at idle condition, to flow the canister. Method takes advantage of an existing pressure sensor (ELCM_PS) which is used for Evap leak detection. A new sensor is required to measure the restriction (CPV_PS). The restriction equation is the delta pressure across the canister (CPV_P...