U046D code meaning
Invalid Data Received From Fuel Pump Control Module B
Network system Generic code U04xx codes Check engine light
What U046D means
U046D is about module B, the second of two fuel pump drivers, used on vehicles with two in-tank pumps or a saddle tank; for module A the matching code is U0410. A receiver, normally the engine controller, logs it when the module's reports, such as delivered pump output or its own fault status, arrive corrupt or implausible. No manufacturer documents U046D publicly. Ford shows that the same exchange can be judged without a U-code: in its 2024 OBD summary the pump B driver answers the engine controller over a duty-cycle feedback line, where 20 % (±4 %) flags an invalid command (P027B), 30 % an internal driver error (P26EA) and 0 or 100 % missing feedback, U016C, judged over 2-5 s with an 11-16 V supply. CARB requires fuel system components to be monitored. Expect the MIL, hesitation under load, hard starting or reduced power.
U046D at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U046D
- Check engine lamp on
- Hesitation or power loss under heavy load
- Long cranking or stalling
Common causes of U046D
- Most likelyPoor ground or corroded connector at the second fuel pump driver
- PossibleDamaged feedback or bus wiring between pump module B and the engine controller
- PossibleWorn pump B drawing excess current and upsetting the driver's reports
- Less likelyInternal fault in fuel pump control module B
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pump module b
What each part of U046D means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6D | The exact fault in that area. |
What to do next
- Note U046D 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 U046D
What does U046D mean?
U046D means "Invalid Data Received From Fuel Pump Control Module B". U046D is about module B, the second of two fuel pump drivers, used on vehicles with two in-tank pumps or a saddle tank; for module A the matching code is U0410. It is a generic code, so it means the same on every make.
Is it safe to drive with U046D?
Drive gently and only to a workshop. With U046D the car can go into limp mode (reduced power) to protect itself.
Will U046D fail an emissions test?
Yes, it can. U046D is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is U046D to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U046D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.