U055D code meaning
Invalid Data Received From Special Purpose Vehicle Control Module D
What U055D means
U055D is the last of the four special purpose controller codes. It is stored when frames from controller D reach the network but carry values the receiver rejects. No manufacturer documents it; even Ford, which names slot A in its 2024 summary as a non-MIL check, says nothing about B to D. In practice the code is most likely on heavily converted vehicles with several add-on units, where one controller may feed implausible values after a voltage dip, a partial software update or a wiring change. Unlike U025C, the lost-communication code, the controller is still transmitting, so power and ground are usually present and the content of the data is what needs checking. Driving is not normally restricted.
U055D at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U055D
- Individual conversion functions fail intermittently
- Fault entry without effect on engine or brakes
Common causes of U055D
- Most likelyIncomplete or interrupted software update of controller D
- PossibleVoltage dip from heavy conversion loads corrupting controller D's output
- Less likelyController D internally faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Special purpose vehicle module d
What each part of U055D means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 5D | The exact fault in that area. |
What to do next
- Note U055D and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U055D
What does U055D mean?
U055D means "Invalid Data Received From Special Purpose Vehicle Control Module D". U055D is the last of the four special purpose controller codes. It is a generic code, so it means the same on every make.
Is it safe to drive with U055D?
U055D does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U055D fail an emissions test?
U055D is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U055D to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U055D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.