Function Explanation (DTC Detection Outline)
- The PCM closes the purge solenoid valve and CV solenoid valve while the vehicle is being driven and seals the fuel tank. Then, gas in the fuel tank is inducted into the intake manifold and the pressure in the fuel tank is decreased by opening the purge solenoid valve, and the pressure change in the fuel tank is measured using the fuel tank pressure sensor. If the pressure in the fuel tank decreases below the target negative pressure during the specified period from the pressure measurement (malfunction determination time (1)), positive pressure is inducted to the fuel tank via the intake manifold by closing the purge solenoid valve and opening the CV solenoid valve. After positive pressure is inducted to the fuel tank, the fuel tank is sealed, opening/closing of the purge solenoid valve is performed repeatedly, and the pressure change in the fuel tank is monitored at that time (malfunction determination time (2)). If the amount of pressure change veers towards negative pressure exceeding the malfunction determination threshold, the PCM determines that there is clogging between the fuel tank pressure sensor and fuel tank, and stores a DTC.
Courtesy of MAZDA MOTORS CORP.