DTC U2100 00: Start Stop Unit Configuration Not Completed: Notes

WARNING: This page is about a different car, the 2014 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC U2100:00 (START STOP UNIT) DETECTION CONDITION AND POSSIBLE CAUSES

Description	Start stop unit configuration not completed
Detection condition	Start stop unit configuration not completed.
Fail-safe function	Although the engine cannot be started with the ignition switched OFF (LOCK) or to ACC, if the ignition is switched ON (engine off), the engine can be started. NOTE: If the start stop unit configuration is not completed, the start stop unit setting will be for an ATX vehicle. For MTX vehicles, if the start stop unit cannot receive the CAN signal, the engine cannot be started because the vehicle cannot be recognized as a MTX vehicle.
Possible cause	Start stop unit configuration error Start stop unit malfunction
System wiring diagram	Not applicable