Electronic Battery Sensor

Typically located on the negative battery terminal, battery sensors measure and inform the ECM of real time battery voltage, amperage, and temperature. The component is a vital member of the BMS battery management system and vehicles with auto start stop systems. The control module uses this information to adjust alternator output more accurately, increasing efficiency while reducing emissions.

A faulty sensor will set a code and illuminate the check engine or other warning lights. It can cause erratic alternator operation resulting in an under or overcharged battery. The ECM will disable the automatic start stop system if a faulty battery current sensor is detected.

Use a multimeter and a scan tool to scan for codes and monitor electronic battery sensor operation. Check with the manufacturer for TSB’s and any special procedures. Inspect and test the battery, the alternator, the wiring in the circuit and the fuse before replacing the sensor.