U055AInvalid Data Received From Special Purpose Vehicle Control Module A
- Generic OBD-II code · Network
- How the car detects it
- Special purpose vehicle control modules are add-on controllers that body builders and upfitters fit to police cars, ambulances, utility trucks and similar conversions. U055A means frames from module A arrive but their content fails the receiver's checks. Ford lists the code in its 2024 OBD operations summary among the powertrain controller's internal plausibility tests and marks it non-MIL for programs carrying a special upfitter module. Ford's 2023 Super Duty shows how such equipment is attached: the factory upfitter integration system passes J1939 signals one way to the body equipment, while the vehicle network itself is encrypted. U0259 is the matching lost-communication code. Expect the upfitter function to misbehave; driving is normally unaffected.
- What you may notice
- Upfitter equipment (lights, outputs, interlocks) works erratically or not at all
- Code stored without warning lamp
- Likely causes
- LikelyUpfitter module programmed or configured for a different vehicle software level
- PossibleVehicle modules updated without matching the upfitter module
- PossiblePoorly made bus connection or splice in the body builder's wiring
- RareSpecial purpose module A internally faulty
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.