Service function guideStart-Stop System Service

This guide covers the complete diagnostic and repair process for a start-stop system that has stopped functioning, from understanding the vehicle's energy management logic to performing the reset and verification steps. It is written for working mechanics and experienced DIYers who already own a scan tool and understand basic electrical testing. After reading, you will be able to identify why the system disabled itself, test the battery sensor and auxiliary battery where fitted, and restore normal operation without replacing parts unnecessarily. The procedure emphasizes safe handling of absorbed glass mat (AGM) and enhanced flooded battery (EFB) batteries and proper registration of any new battery to the vehicle's power management system.