Vehicle diagnosing apparatus

摘要

A portable diagnosing unit is connected to an electronic control unit (ECU) which is mounted on a vehicle. The diagnosing of the vehicle is performed by the portable diagnosing unit via the ECU according to the diagnosing program corresponding to the kind of ECU. The diagnosing data are transmitted to the host computer for processing. In this vehicle diagnosing apparatus, a diagnosing program for each kind of ECU is stored in the host computer. A diagnosing program corresponding to that kind of ECU which is read out by the portable diagnosing unit is transmitted from the host computer to the portable diagnosing unit. When the kind of ECU of the preceding vehicle is the same as the kind of ECU of the succeeding vehicle, the diagnosing program that was earlier received by the portable diagnosing unit which is connected to the ECU of the preceding vehicle is transmitted from that portable diagnosing unit to the portable diagnosing unit which is connected to the ECU of the succeeding vehicle.