Faulty Energy Storage Box (ESB) Battery
Faulty Battery Energy Control Module (BECM)
Battery Energy Control Module (BECM) harness is open or shorted
Battery Energy Control Module (BECM) circuit poor electrical connection
Engine Light ON (or Service Engine Soon Warning Light)
Battery voltage sensors allow the Energy Storage Control Module (ESCM) to monitor the voltage of the batteries in the Energy Storage Box (ESB). The batteries apply voltage to internal input resistors that are connected to the signal circuits of the battery voltage sensors. The module provides ground to the battery voltage sensors through the reference circuit. The ESCM monitors the voltage drop across the battery voltage sensors and uses the inputs for hybrid calculations. When the battery voltage is high, the resistances of the sensors are high and the voltage signals are high. When the battery voltage is low, the resistances of the sensors are low and the voltage signals are low.