Ford is recalling certain 2021-2022 Mustang Mach-E vehicles because the high voltage battery main contactors may overheat, causing the vehicle to lose drive power. The defect affects 48,294 vehicles.
In the defective vehicles, DC fast charging and repeated wide-open pedal events can cause the high voltage battery main contactors to overheat. Overheating may lead to arcing and deformation of the electrical contact surfaces, which can result in a contactor that remains open or a contactor that welds closed.
If the contactor opens while driving, a powertrain malfunction warning light illuminates and the vehicle will display “Stop Safely Now” in the cluster when the vehicle experiences an immediate loss of motive power. If the contactors weld closed while driving, a powertrain malfunction warning light illuminates on the next drive cycle, along with a no-start condition.
Between 13 July 2021 and 31 May 2022, there have been 286 warranty claims in North America related to an open or welded contactor. Ford is aware of one VOQ alleging a no-start and listing DTCs related to this.
The remedy for this is a Secondary On-Board Diagnostic Control Module (SOBDMC) and Battery Energy Control Module (BECM) software update. Ford is anticipated to begin Over-The-Air (OTA) deployment to update the SOBDMC and BECM software for affected vehicles in July 2022. Alternatively, owners will have the option to take their vehicle to a Ford or Lincoln dealer to complete the software update. There will be no charge for this service.
The updated SOBDMC software will monitor contactor temperature and intelligently reduce battery power to prevent damage to the contactor. The updated BECM software will monitor contactor resistance to identify an overheated contactor and reduce vehicle power to prevent further damage.
Ford has not issued instructions to stop driving vehicles under this safety recall. The updated software was introduced into production on 25 May 2022.