TRIONIC Engine Management System

Trionic engine management system controls idle speed, fuel, turbo boost and ignition from one Engine Control Module (ECM). Mass air flow control is achieved by regulating turbocharger boost pressure on Trionic T-5 and Trionic T-7 4-cylinders, and throttle position on T-7 V6 engines. Fuel injection system control relies heavily on HO2S, Engine Coolant Temperature (ECT), Throttle Position (TP) Sensor and Mass Airflow (MAF) sensors to regulate fuel injector opening and duration times. Several other sensors are used to fine-tune EFI system. T-5 system uses an Idle Air Control (IAC) valve to regulate idle speed, while T-7 uses ECM to control throttle position at idle. T-7 also uses pedal position sensors to regulate throttle position, and is not directly connected to accelerator pedal unless a throttle-related malfunction occurs. Then, a limp-home solenoid directly links throttle with gas pedal.

Each spark plug has an individual coil that is integrated into ignition discharge module, which sits on top of the engine. Ignition timing is established by ECM by measuring resistance of each spark plug. As fuel in the cylinders is compressed and ionization of fuel molecules takes place, resistance across spark plug electrode drops. At a predetermined point, the ECM uses resistance drop to trigger ignition. Because resistance is also affected by knocking or pinging, ignition timing, fuel system and turbo boost can all be controlled in this manner. The need for Camshaft Position (CMP) sensor or Knock Sensor (KS) is eliminated.

When ignition is switched on, both main relay and fuel pump relay operate for a few seconds. As soon as ECM senses that crankshaft has begun to rotate, coolant temperature dependent fuel injection takes place through injectors simultaneously. This enables short starting time to be achieved. If engine is started and shortly afterward switched off again, a fresh pre-injection sequence will be obtained if 45 seconds is allowed to pass with ignition switched off.