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U025F Lost Communication With Electronic Brake Booster Control Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Second brake unit without power or ground (separate fuse or supply path)
Damaged bus wiring or connector to the redundant unit
Internal failure of brake unit B

Symptoms

  • Brake system or driver-assist warning in the cluster
  • Automated or assisted driving functions unavailable

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,000
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

electronic brake booster module bvehicle bus wiring

Related codes

U0560U025EU034BU0121

References: bosch-mobility.com, bosch-mobility.com, static.nhtsa.gov.