PROCEDURE AND INSTRUCTION FOR TESTING THE FUNCTIONALITY OF A TANK AIR.

摘要

PCT No. PCT/DE93/00019 Sec. 371 Date Oct. 4, 1993 Sec. 102(e) Date Oct. 4, 1993 PCT Filed Jan. 14, 1993 PCT Pub. No. WO93/15313 PCT Pub. Date Aug. 5, 1995.A method for checking the operability of a tank-venting system in a vehicle having an internal combustion engine, which tank-venting system has a tank with a tank-pressure sensor, an adsorption filter connected to the tank via a tank-connecting line, and a tank-venting valve which is connected to the adsorption filter via a valve line, in which system the adsorption filter has a venting line which can be closed with the aid of a shut-off valve, has the following steps: closing the shut-off valve; opening the tank-venting valve; determining the build-up gradient (p+) of the underpressure building up in the tank; closing the tank-venting valve; determining the decay gradient (p-) of the decaying underpressure in the tank; mathematically combining the build-up and decay gradients in a manner such that the influence of the fill level has as little effect as possible on the evaluation variable (Q) formed by means of the combination; and, comparing the value of the evaluation variable with a threshold value (Q-SW) and evaluating the system as non-operative if the value of the evaluation variable and the threshold value fulfill a pregiven relationship.