Function Explanation (DTC Detection Outline)

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

The fuel tanks of AWD vehicles have a saddle-like shape, with a main side and sub side.
The PCM monitors the fuel levels in the fuel tank (main) and fuel tank (sub).
If the transfer function is malfunctioning, the fuel transfer amount from the fuel tank (sub) to the fuel tank (main) decreases and only the fuel in the fuel tank (main) decreases.
The PCM determines that the above condition is a malfunction, and stores a DTC.