TSB 21-2405

Some 2021 Mustang Mach-E vehicles built on or before 09-Sep-2021 may exhibit an illuminated powertrain malfunction indicator (wrench) lamp and/or display the message Shift System Fault Service required with DTC U0103:87 stored in the secondary on board diagnostic module (SOBDMC). Some vehicles may also exhibit DTCs U0100:00, U0121, U0140, and/or U0155 stored in the gear shift module (GSM). This may be due to the software in the GSM. To correct the condition, follow the Service Procedure to reprogram the GSM.