Circuit for automatic shut-down of electronically controlled diesel engine

摘要

An engine diagnostic testing procedure requires that the fuel shut-off solenoid valve remain connected to the engine's electronic control module during diagnostic testing. A normally closed set of contacts of a relay is interposed in the wiring between the module and the valve. This relay is part of an automatic shut-down circuit that uses several principal components of a known shut-down system along with two additional relays and three diodes to provide the engine with an automatic shut-down system that is independent of the engine's electronic control module, yet that will not disconnect the fuel shut-off solenoid valve from the electronic control module during diagnostic engine testing.