DTC P2503:00: Notes

DTC P2503:00	Charging system voltage low input
DETECTION CONDITION	The PCM needs more than 20 A from the generator, and determines that the generator output voltage is below 8.5 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	Drive belt exceeds limit Generator connector or terminals malfunction Short to ground in wiring harness between the following terminals: Generator terminal D-PCM terminal 2AA Generator terminal P-PCM terminal 2AF PCM connector or terminals malfunction Open circuit in wiring harness between the following terminals: Generator terminal D-PCM terminal 2AA Generator terminal P-PCM terminal 2AF Generator malfunction PCM malfunction
Courtesy of MAZDA MOTORS CORP.