U025F code meaning
Lost Communication With Electronic Brake Booster Control Module B
What U025F means
U025F concerns a second electronic brake booster control unit, B. No manufacturer documents this code publicly, and none states which physical unit would carry the letter. Bosch describes where two units make sense: in automated vehicles its integrated power brake, which merges boosting and stability control in one unit, is backed by a separate redundant brake unit, and the iBooster together with ESP supplies the redundancy such cars require. Ford's booster (Escape, Explorer, Bronco Sport, Aviator and Corsair of 2020-2021) shows that a power interruption at that unit lights the ABS and stability lamps through a code in the ABS module (SSM 51374). If unit B goes silent, expect brake or driver-assist warnings and the loss of the backup path, which can switch off automated driving. Unit A is U025E.
U025F at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U025F
- Brake system or driver-assist warning in the cluster
- Automated or assisted driving functions unavailable
Common causes of U025F
- Most likelySecond brake unit without power or ground (separate fuse or supply path)
- PossibleDamaged bus wiring or connector to the redundant unit
- PossibleInternal failure of brake unit B
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Electronic brake booster module bVehicle bus wiring
What each part of U025F means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 5F | The exact fault in that area. |
What to do next
- Note U025F 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 U025F
What does U025F mean?
U025F means "Lost Communication With Electronic Brake Booster Control Module B". U025F concerns a second electronic brake booster control unit, B. It is a generic code, so it means the same on every make.
Is it safe to drive with U025F?
Drive gently and only to a workshop. With U025F the car can go into limp mode (reduced power) to protect itself.
Will U025F fail an emissions test?
U025F 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 U025F to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will U025F clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.