EDIT\24y04m05d
How to quickly reset BMS with no special tools...
https://www.fiestastforum.com/threads/battery-monitoring-system.25904/post-478335
Video info detailing how it functions...
https://www.fiestastforum.com/threads/is-battery-management-module-necessary.28373/post-506601
24y04m05d/EDIT
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Quote from the 2016 service manual...
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Battery Charging
When it is required to charge the vehicle battery, connect the positive connection to the battery positive post, and place the charger negative to vehicle ground. Do not connect the negative cable of the charger to the battery negative terminal. Connecting directly to the battery negative post bypasses the battery monitoring sensor not allowing the sensor to detect the charge current. As a result the battery state of charge does not reflect the charging. Look for the body ground cable coming off the battery monitoring sensor and try and connect in this location (typically on the shock tower sheet metal). The placement of the battery is such that the battery negative terminal is located under the sheet metal shroud making sheet metal ground the obvious choice for the charger.
If the battery is being charged due to a load shedding message, only charging the battery properly assists in clearing this message. The Electrical Energy Management recalibrates the battery state of charge as described above after about 8 hours if the charger was improperly installed.
NOTICE: If the charger is incorrectly connected to the battery negative terminal, DO NOT reset the battery monitoring system using the diagnostic scan tool. This reset is reserved only for new battery installation. This reset clears the learned battery data, the battery time in service, and affects the aging algorithm parameters, which have been learned since the installation of the battery.
Jump Starting
When it is required to jump start the vehicle, just like battery charging, it is important to connect the cables properly for the Electrical Energy Management system to measure the energy input to the system to keep an accurate State of Charge. Connect the positive connection to the battery positive post, and connect the Jump Start negative to the vehicle ground. Do not connect to the negative battery terminal. Connecting directly to the battery negative post bypasses the ability of the vehicle to measure the input current with the battery monitoring sensor, and does not adjust the battery state of charge accordingly. For a convenient ground location look for the body ground cable coming off the clamp or the Battery Monitor Sensor and try and connect in this location (typically on the shock tower sheet metal). The Electrical Energy Management recalibrates the battery state of charge as described above after about 8 hours if the jump start negative cable is improperly installed.
NOTICE: If the cables are incorrectly connected to the battery negative terminal, DO NOT reset the battery monitoring system using the diagnostic scan tool. This reset is reserved only for new battery installation. This reset clears the learned battery data, the battery time in service, and affects the aging algorithm parameters, which have been learned since the installation of the battery.
Battery Replacement
If the vehicle battery is replaced, it is very important to perform the battery monitoring system reset using the scan tool. If the battery monitoring system reset is not carried out, it holds the old battery parameters and time in service counter in memory. Additionally it tells the system the battery is in an aged state and the may limit the Electrical Energy Management system functions. For more information,
Refer to:
Battery and Cables - System Operation and Component Description (414-01 Battery, Mounting and Cables, Description and Operation).
