U044D code meaning
Invalid Data Received From Generator B Control Module
What U044D means
U044D names the generator B control module. Ford uses the A version for its LIN-controlled alternator: in SSM 50737, 2021-22 F-150 trucks with the 2.7L EcoBoost warn about the charging system and store U012D and U042E in the PCM because a LIN wire rubs through to ground close to the engine mount on the left. A B unit would then be the regulator of a second alternator, as found on trucks with dual generators; Ford's 2014 code list already contains circuit codes for generator 2. U044D is set when that regulator answers but its status, load or fault data are invalid; U012F is lost contact. No manufacturer documents U044D publicly. The engine computer then cannot steer the second alternator reliably, so charging capacity may drop and a battery or charging warning may appear.
U044D at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U044D
- Battery or charging system warning
- Low charging voltage under high electrical load
Common causes of U044D
- Most likelyChafed or shorted LIN wire to the second alternator
- PossibleFaulty voltage regulator of alternator B
- Less likelySecond alternator not configured correctly in the engine computer
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Generator module bAlternator
What each part of U044D means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4D | The exact fault in that area. |
What to do next
- Note U044D 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 U044D
What does U044D mean?
U044D means "Invalid Data Received From Generator B Control Module". U044D names the generator B control module. It is a generic code, so it means the same on every make.
Is it safe to drive with U044D?
U044D does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U044D fail an emissions test?
U044D 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 U044D to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will U044D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.