DTC P025B:00 [MZI-3.7]: Notes

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DETECTION CONDITION & POSSIBLE CAUSE

DTC P025B:00	Fuel pump control circuit-range/performance
DETECTION CONDITION	The electronic fuel pump relay monitors the duty cycle and frequency of the signal it receives from the PCM. The fuel pump control module determines if the signal from the PCM on the fuel pump command (FPC) circuit is a valid duty cycle and frequency. If the duty cycle or frequency is invalid, the fuel pump control module sends a 20% duty cycle signal on the fuel pump monitor (FPM) circuit to report the concern to the PCM. The test fails if the fuel pump control module is still reporting that it is receiving an invalid duty cycle or frequency from the PCM after a calibrated amount of time.
POSSIBLE CAUSE	Open circuit between electronic fuel pump relay terminal C and PCM terminal 1BI Short to ground between electronic fuel pump relay terminal C and PCM terminal 1BI Short to power supply between electronic fuel pump relay terminal C and PCM terminal 1BI Radio frequency interference/electromagnetic interference (RFI/EMI) Electronic fuel pump relay malfunction PCM malfunction
Courtesy of MAZDA MOTORS CORP.