Function Explanation (DTC Detection Outline)

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 fuel transfer function is malfunctioning, fuel cannot be transferred from the fuel tank (sub) to the fuel tank (main) and only the fuel in the fuel tank (main) decreases.
The PCM determines that the above condition is a malfunction, and stores a DTC.