Technical Service Bulletin SSM 53759 — 2024 FORD F-550 SD

After replacement of any TRON module, the gateway module (GWM) and the TRON capable modules can set diagnostic trouble codes (DTCs) U211A, U211B, U211C, U3034, U3035, U3036, U35D9, U35DA and/or U35DB if the secret authentication security keys are not aligned between the modules, a loss of communication is occurring between modules and/or a module is not responding. This may be a result of missing the new module secret authentication security key obtained when running the Ford Diagnosis and Repair System (FDRS) "Trusted Real-Time Operation Network (TRON) Module Authentication" procedure after replacement. When replacing a TRON capable module, run the FDRS "Trusted Real-Time Operation Network (TRON) Module Authentication" procedure in the GWM tool box, not in the toolbox of the module with the DTC's, to distribute a new set of secret authentication security keys to all TRON-capable modules. Using the specific vehicle identification number (VIN), refer to Workshop Manual (WSM), Section 418-00 and 418-01 for updated DTCs, applicable TRON module listings and pinpoint tests.