Method and system for testing internal combustion engine computerized

Abstract

A control unit installed in a vehicle, particularly a control unit to control an internal combustion engine (ICE) thereof, has within its already present computation stage, a program store or program memory (PS, 2b') which stores a test program (TP) therein. The program store (PS) also includes an operating program memory (OP) used to control operation of the vehicle and/or the ICE thereof. The test apparatus includes a test computer and comparator (1) and a simulation and measuring unit which applies simulated input signals to the vehicular control unit, for example sequentially and only to single inputs thereof. The test program within the vehicular control unit is then run under control of the test computer and forwards the data referring to the applied signals via the serial interface 5 to the test computer 1 for evaluation. The test computer can also control the test program, resulting in output signals which are measured in the simulation and control unit (6) and applied as measured results to the test computer and comparator for evaluation and checking against desired or standard values. The normal operating program, likewise, can be read out for checking. The simulation and control unit may, for example, include a resistance network which is sequentially, selectively connected to the vehicular control unit under control of the computer and comparator (1) to provide appropriate input signals to selected input terminals.