This procedure is only for vehicles equipped with a Battery Sensor Module. Attempting to
run this procedure without a Battery Sensor Module may cause unwanted results. If this
occurs, the BCM will need to be reset with an ignition cycle.
The Battery Sensor Module is attached directly to the battery negative terminal and is used to
determine the battery condition by calculating the battery state of the battery’s charge, functions,
and state of health. The battery condition is used to help determine if the 12 V start-stop system
will allow a start-stop when the vehicle has come to a stop.
To determine the battery’s condition, the battery sensor must be calibrated. In normal operation,
all current entering or exiting the battery flows through the Battery Sensor Module and is
monitored. Any action which charges or discharges the battery that is not monitored by the
Battery Sensor Module will require the calibration procedure to be performed. Examples are:
The battery was replaced by a battery with the same part number
The battery was replaced by a battery with a different part number or different
specifications
The battery was charged while outside the vehicle
The battery was discharged while outside the vehicle
The battery was improperly charged:
To properly charge the battery, the negative lead of the charger must be connected to
chassis ground, and NOT directly to the negative battery post. Connecting to chassis ground
allows current to flow through the Battery Sensor Module during charging as well as be
monitored. Connecting directly to the negative battery post charges the battery, but the
current cannot be monitored by the Battery Sensor Module.
Other situations that also require the calibration procedure to be performed include:
The Battery Sensor Module was not calibrated correctly
The Battery Sensor Module was disconnected and reconnected
No open circuit voltage reading of up to 1 circle
If any of above conditions have occurred, the Battery Sensor Module must be calibrated to
maintain a proper 12 V start-stop operation.
Diagnostic Aids
Excessive battery draws will prevent the B110 Battery Monitor Module (Battery Sensor )
learn from completing successfully.
If the Battery Sensor Module state of Charge Error and verify it is less than 10% the auto
stop/start system will be disabled.
Calibration Procedure