Fuel Tank System

Testing for leakage in the fuel tank system is running. During the first half of the test, major leaks (leaks larger than 1.0 mm) can be detected. Diagnostic trouble code (DTC) is stored in the engine control module (ECM) if leakage is detected.

After a certain amount of time (time is dependent on the fuel level in the tank) the engine control module (ECM) assesses the seal of the fuel tank system. Assessment is made using the results of the calculations of time, measured reference power consumption of the pump, measured power consumption of the pump during the time of assessment and from the shape of the power supply curve and characteristics during pressurization. If the leak in the fuel tank system is larger than 0.5 mm but smaller than 1.0 mm a diagnostic trouble code (DTC) is stored for minor leakage in the engine control module (ECM).