Automotive Vehicle Strategies and Ecm Modes

Book excerpt: Automotive Vehicle Strategies and ECM Modes(Diagnostic Strategies of Modern Automotive Systems)By Mandy ConcepcionThis book is divided into two sections, “Vehicle Operational Strategies”, which detail what's needed for and engine to start. In other words, this section concentrates on the signals needed for a particular manufacturer to make the engine run. These signal strategies are true regardless of the system and the section simply zeros in on the actual signal, whether it's a distributor, DIS, COP, etc. The second section is the "ECM operational modes" and goes into details on why and how the ECM does what it needs to do to run the engine. In other words, this section has to do with the behavior of the ECM according to outside conditions.VEHICLE OPERATIONAL STRATEGIESThis section is designed to serve as a functional guide to some of the more difficult to diagnose faults. It basically came about from the trial and error experimentation with different systems, during the diagnostic process. It is not a study section per se, but will definitelyenlighten the technician as to the logics of different systems on the market today. Hopefully, it will serve to pinpoint the source of an actual problem.ECM OPERATIONAL MODES In this section, we'll take a look at automotive OPERATIONAL MODES. The section deals with the specifics of internal ECM programming strategies. The knowledge gained here will aide the modern technician is deciphering why is the ECM functioning in a specific way. This section, as in other parts of this book, helps to answer the technician's diagnostic basic question “What is the ECM seeing, that's causing it to do what it does?”Table of ContentsVEHICLE OPERATIONAL STRATEGIES- HONDA IGNITION & INJECTION STRATEGY- MAZDA IGNITION STRATEGY- MAZDA EEC IV IGNITION STRATEGY- MITSUBISHI/HYUNDAI IGNITION STRATEGY- NISSAN IGNITION STRATEGY- NISSAN COP IGNITION STRATEGY- TOYOTA IGNITION STRATEGYECM OPERATIONAL MODES• CRANKING ENRICHMENT MODE• ENGINE WARM-UP MODE• OPEN-LOOP MODE• CLOSE-LOOP MODE• ACCELERATION ENRICHMENT MODE• DECELERATION ENLEANMENT MODE• IDLE SPEED CONTROL MODE• LOW VOLTAGE CORRECTION MODE• CLEAR FLOOD MODE• SELECTIVE FUEL INJECTOR CUT-OFF MODE• LIMP-HOME MODE• EXHAUST VARIABLE VALVE TIMING/EGR CONTROL MODE