Possible causes

– Low battery voltage
– Faulty Powertrain Control Module (PCM)
– PCM harness is open or shorted
– PCM circuit poor electrical connection

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P2507 MAZDA Description

When the ignition switch is turned “ON”, battery voltage is applied from the battery to the Powertrain Control Module (PCM) through the main relay. In case that the ignition switch is turned “OFF”, the PCM is supplied with power through the battery power input line to control the basic operation of vehicle.