Charging System - Generators & Regulators: Operation

The Powertrain Control Module (PCM) maintains a system charging voltage of approximately 13-15 volts. PCM determines a target voltage based on monitored voltage and inputs from battery temperature sensor. PCM compares target and battery voltages whenever engine is running. If battery voltage is less than target voltage, PCM will increase field current. If battery voltage is greater than target voltage, PCM will decrease field current.