U0440 code meaning
Invalid Data Received From Pedestrian Alert Control Module
What U0440 means
U0440 points at the pedestrian alert control module, which drives the external speaker of electric and hybrid vehicles. FMVSS 141 in the US demands an audible signal while the vehicle stands with its propulsion active and at speeds below 30 km/h, so the module needs speed, gear and propulsion state and reports its own status back. A receiver sets U0440 when the module's frames arrive with invalid content. No manufacturer documents U0440 publicly; Ford names the part PACM, for instance in bulletin 21-2271 about a rattle from its connector in the 2020-21 Escape Hybrid. The likely result is a warning about the pedestrian alert system: the car stays drivable, but may be quieter than the rule allows at low speed. U013F is lost contact.
U0440 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0440
- Pedestrian alert system warning in the cluster
- No external sound at low speed
Common causes of U0440
- PossibleLoose or vibrating connector at the alert module
- PossibleAlert module software not matched to the vehicle
- Less likelyInternal fault of the pedestrian alert module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pedestrian alert control module
What each part of U0440 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 40 | The exact fault in that area. |
What to do next
- Note U0440 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 U0440
What does U0440 mean?
U0440 means "Invalid Data Received From Pedestrian Alert Control Module". U0440 points at the pedestrian alert control module, which drives the external speaker of electric and hybrid vehicles. It is a generic code, so it means the same on every make.
Is it safe to drive with U0440?
U0440 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0440 fail an emissions test?
U0440 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 U0440 to fix?
Difficulty: medium. A typical repair takes 0.3 to 1.5 hours of work. This is a job for a workshop.
Will U0440 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.