Patent ID: 6873919

Claim:
A method for diagnosing a transmission of a motor vehicle by analyzing oil flowing within the transmission and detecting ferritic wear particles which accumulate within the oil during operation of the transmission, the method comprising the steps of: placing a reed contact ( 1 ) in an upper region of an oil duct ( 4 ) of the transmission and locating a capturing magnet ( 2 ), opposite from the reed contact ( 1 ), in a lower region of the oil duct ( 4 ); accumulating the ferritic wear particles on the capturing magnet ( 2 ) and producing a magnetic flux density, via the capturing magnet ( 2 ), over a cross-section of the oil duct ( 4 ) with the magnetic flux density changing due to accumulation of the ferritic wear particles ( 2 ) on a surface of the capturing magnet ( 2 ); using a sensor, built into an oil duct ( 4 ) of the transmission, as part of the measurement system; detecting the change in the magnetic flux density by the reed contact ( 1 ) and producing an output signal from the reed contact ( 1 ) which is indicative of a condition of the transmission for determining when serving of the transmission is necessary; and displaying, via an indicator, that servicing of the transmission is required.