DTC P2502:00: Notes

DTC P2502:00	Charging system voltage problem
DETECTION CONDITION	The PCM determines that the generator output voltage is above 17 V and battery voltage is below 11 V for 5 s while the engine is running. Diagnostic support note This is a continuous monitor (other). The check engine light does not illuminate. FREEZE FRAME DATA (Mode 2)/Snapshot data is not available. The DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	-
POSSIBLE CAUSE	Battery malfunction Loose generator terminal B installation nut Battery positive terminal is poorly connected Short to ground or open circuit in battery charging circuit Short to ground in wiring harness between MAIN ST 250 A fuse and generator terminal B MAIN ST 250 A fuse malfunction Open circuit in wiring harness between battery positive terminal and generator terminal B Generator malfunction PCM malfunction
Courtesy of MAZDA MOTORS CORP.