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B156D on the 2021 Ford F-450

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

This code is specific to a manufacturer and is not described here. Its meaning is in the manufacturer's service information.

Bulletins for this model year that name B156D
SSM 545892026-03-04. Other. Some 2019-2024 Ford and Lincoln vehicles equipped with SYNC3 may experience various connectivity concerns with The Ford App Lincoln App including but not limited to: missing activation prompt pop-upon the vehicle's center display screen when attempting to activate vehicle through The Ford App Lincoln App, incorrect location global positioning system GPS reported through The Ford App Lincoln App, problems with remote commands being performed through The Ford App Lincoln App and or incorrect data information reported on The Ford App Lincoln App. These symptoms will be accompanied by diagnostic trouble code DTC B156D 89 in the TCU. This may be due to the accessory protocol interface module APIM software. To correct the condition, update the APIM software.
SSM 527222024-08-06. Service bulletin. Some 2019-2024 Ford and Lincoln vehicles equipped with SYNC3 may experience various FordPass/LincolnWay connectivity concerns including but not limited to: missing activation prompt (pop-up) on the vehicle's center display screen when attempting to activate vehicle through FordPass/LincolnWay, incorrect location/global positioning system (GPS) reported through FordPass/LincolnWay, problems with remote commands being performed through FordPass/LincolnWay, incorrect data/information reported on FordPass/LincolnWay. These symptoms will be accompanied by diagnostic trouble code (DTC) B156D:89 in the TCU. This may be due the accessory protocol interface module (APIM) software
SSM 503462021-12-26. Service bulletin. Some 2018-2021 Ford and Lincoln vehicles may exhibit inoperative remote features via the Ford Pass/Lincoln Way mobile app, incomplete user authorization, no modem electronic serial number (ESN) displayed or DTCs U2100 and/or B156D in the telematics control unit (TCU). These symptoms may persist even after performing a TCU software update and/or replacement. To correct this condition, start a new session with the latest version of the appropriate diagnostic scan tool and perform a PMI on the TCU. If issues persist, open a hotline assistance request and include the IDS version (if applicable) used to perform the PMI and the Authorization Status PID value in the TCU datalogger. For claiming use causal part 14G229 and applicable labor times in Section 10 of the Service Labor Time Standards (SLTS) Manual.

3 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.