if it looks like an outline of an engine it has to do with emissions and not with engine safety. there is a six hole rectangular plug near the battery with a black cover on it. remove the cover and with the holes facing you, wires away, lock tab on top, short the first and second terminals on the bottom row. turn the key on and count the flashes. after you check code disconnect battery and if not a hard code it will reset. there are only 5 codes
code 1. lean or rich, idle high or low. this is the most common code and is often idle related
code 2 is same as 1 but for gasoline
code 3 is vacuum sensor, usually broken wires
code 4 is temp sensor
code 5 is gasoline engine code. multiple fuel sources on