| 摘要 |
The invention is directed to a method of checking the operability of a tank-venting apparatus for a motor vehicle having a fuel tank and an internal combustion engine including an air intake pipe. The method includes the steps of: measuring the temperature of the adsorption material with a first temperature sensor before the first regeneration of the adsorption material after a tanking operation; measuring the temperature of the adsorption material at a pregiven time point after the start of the first regeneration; forming the material temperature difference between the first and second measured values ( theta 1-V- theta 1-N); measuring the temperature of the venting air close to the adsorption material with a second temperature sensor in advance of the first regeneration; measuring the temperature of the venting air at a pregiven time point after the start of the first regeneration; forming the venting-air temperature difference between the second and first measured values ( theta 2-N- theta 2-N); subtracting the venting-air temperature difference from the material temperature difference to obtain a regeneration temperature difference; comparing the regeneration temperature difference to a threshold value; and, evaluating the apparatus as operational when the regeneration temperature difference exceeds the threshold value and, if not, then evaluating the apparatus as being inoperable. This method affords the advantage that temperature effects no longer constitute a disturbance when checking temperature changes of the adsorption material by means of regeneration operations with the temperature effects being caused by the venting air.
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