The fuel injection is fully sequential and is dependent on the MAP (Manifold Absolute Pressure).
Boost pressure control (L and R engines) utilises a solenoid valve pneumatically connected to the turbocharger’s waste gate.
To ensure as optimal combustion as possible and with that lower exhaust emission the injectors are equipped with four holes, which gives a good distribution of the fuel.
As soon as the ECU gets the cranking signal (from the crankshaft sensor) it initiates a coolant temperature dependent fuel injection with all four injectors simultaneously which ensures a fast engine start.
To decide how much fuel needs to be injected into each intake runner the ECU calculates the air mass that had been drawn into the cylinder.
Since the flow capacity of the injector and the density of the fuel (pre programmed values) are known, the ECU can calculate the duration of the injection.
During a cold start and warm up, before lambda correction is activated, coolant temperature dependable fuel enrichment occurs.
With a warm engine and normal battery voltage the duration of injection varies between 2,5 ms at idle and approx.
The content of oxygen in the exhaust fumes is measured through a chemical reaction, this results in an output voltage.
The pre heating element is fed by B+ via fuse 38 and the main relay, the sensor is grounded in the ECU via pin 50.
The need to correct the injection duration is due that the volumetric efficiency of the cylinder is dependent on the engines RPM.
At to low basic charging pressure the engine doesn’t revs up as expected when the throttle is opened quickly.
In addition there is a substantial risk of engine damage since the charging pressure can’t be lowered enough when regulating with attention to pre ignition/pinging.
After adjustment the push rod must have at least two turns (2 mm) pre tension when connecting to the waste gate lever.
On new turbo chargers the basic charging pressure tends to be near or spot on the upper tolerance when the pre tension is two turns.
At WOT the pressure values for each RPM are selected to make sure that the engine gets the requested torque.
The correction factor (adaptation) is then stored in the memory of the ECU and is always used in the calculation of the PWM signal.
The rationale with this is to make sure that the actual pressure as soon as possible will be equal to the required after a change of the load has occurred.
The red ignition cassette used with Trionic 5 is mounted on the valve cover on top of the spark plugs.
The cassette is electrically supplied with battery voltage from the main relay (B+) and is grounded in an earth point.
When the main relay is activated the battery voltage is reformed to 400 V DC which is stored in a capacitor.
To the ignition cassette there are four triggering lines connected from the Trionic ECU, pin 9 (cyl.
To facilitate start when coolant temperature is below 0°C the ECU will ground each trigger line 210 times/second between 10° BTDC and 20° ATDC, at which a “multi spark” will appear.
During engine operations the Ignition cassette continuously monitors the ion currents in the cylinders and sends a signal to the Trionic ECU, pin 44, in an event of knocking.
The logic for this function rests solely in the ignition cassette and is adaptive to be able to handle disturbing fuel additives.
The Trionic ECU is well aware which cylinder that has ignited and could hence cope with the information feed through one pin.
If the signal between the ignition cassette and the ECU is lost, the charging pressure is lowered to basic charging pressure and the ignition timing advance is lowered 12° when it exist a risk of knocking due to engine load.
If combustion occurs in cylinder one or two the ignition cassette sends battery voltage (B+) pulse to the ECU, pin 17.
In case of a Heat Plate-failure the car may have drivability problems due condensed fuel in the intake during cold engine operations.
The light is lit at a higher RPM when the engine is cold to promote a quicker warm up.