DTC P1549: General Description
Driven by the engine, the alternator generates electricity to supply the necessary power to the electrical system and to charge the 12 volt battery. The alternator voltage target values from 12.5 V to 14.5 V are achieved by switching the alternator control mode (controlled by the powertrain control module (PCM)). The alternator output signal is sent to the PCM, and it varies according to the 12 volt battery's state of charge, the electrical load, and the engine speed. When the IGP terminal voltage is a set value for a set time, the PCM detects a malfunction and stores a DTC.