FORD · 2021-12-07
Some 2021-2022 F-Super Duty vehicles equipped with 4x4 may exhibit an illuminated powertrain malfunction (wrench) indicator and a 4x4 warning lamp with DTC P1812 stored in the transfer case control module (TCCM). DTC P1812 can set if the 4X4 selector switch is inadvertently left between detents of the switch during operation. If DTC P1812 is present, cycle the 4X4 selector switch several times and retest. If the DTC persists, inspect the selector switch connector for bent or pushed out pins. If no concerns are identified, refer to Workshop Manual (WSM), Section 308-07A pinpoint test D.