TSB 23-2135

Some 2021-2022 Bronco vehicles equipped with a 2.7L or 3.0L EcoBoost engine may exhibit various charging system error messages and/or illuminated charging system indicator displayed in the instrument panel cluster (IPC) with diagnostics trouble code (DTC) B11DB set within the body control module (BCM). This may be due to coolant contamination into the battery monitor sensor (BMS) from a leaking transmission fluid heater coolant control valve. To correct the condition, follow the Service Procedure to clean the BMS connector and replace the transmission fluid heater coolant control valve.