Fresh air leakage diagnosing method for e.g. main air cooler of compressed fresh air system in oil engine of motor vehicle, involves deducing air leakage diagnosis based on result of comparison between leakage section and threshold value

摘要

The method involves measuring a value of a variable representing operation of an internal combustion engine (1). A fresh air leakage section in a main air cooler (23), a compressor and main air cooler connecting pipe (26) or an air distributor and main air cooler connecting pipe (27) of a compressed fresh air system is calculated based on the measured value. The leakage section is compared with a determined threshold value, and a fresh air leakage diagnosis is deduced based on the comparison result. Presence of fresh air leakage is deduced if the leakage section exceeds the threshold value. An independent claim is also included for an internal combustion engine comprising cylinders.