Abstract: An interactive method for testing vehicle electronics systems is disclosed in which various vehicle subsystems are exercised under the control of the tester unit while the performance of associated subsystems are monitored to detect and isolate malfunctions. The tester includes interchangeable program cartridges that can be easily inserted to adapt the unit for a variety of different vehicles and test procedures, and also optional interchangeable input/output cartridges for test procedures in which additional access to or from the tester or peripheral devices is necessary. The test unit accesses the vehicle's electronics data bus by means of an assembly line diagnostic link, the access being accomplished via a multiplexer that makes it possible to locate faults on the data bus itself. The tester greatly reduces the time and effort necessary to analyze malfunctions in the field, and is considerably more comprehensive than prior test equipment.

Abstract: An interactive system and method for testing vehicle electronics systems is disclosed in which various vehicle subsystems are exercised under the control of the tester unit while the performance of associated subsystems are monitored to detect and isolate malfunctions. The tester includes interchangeable program cartridges that can be easily inserted to adapt the unit for a variety of different vehicles and test procedures, and also optional interchangeable input/output cartridges for test procedures in which additional access to or from the tester or peripheral devices is necessary. The test unit accesses the vehicle's electronics data bus by means of an assembly line diagnostic link, the access being accomplished via a multiplexer that makes it possible to locate faults on the data bus itself. The tester greatly reduces the time and effort necessary to analyze malfunctions in the field, and is considerably more comprehensive than prior test equipment.