Network, generic (extended)

U301D Control Module Wake-up Circuit A Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

U301D says wake-up line A is electrically intact but its level does not fit what the module expects at that moment. Ford uses it in the battery energy control module of the 2019 Fusion Energi plug-in hybrid. Its OBD summary files the code under the charging performance checks: while the charger is precharging and its output voltage is already within the window for closing the charge contactors, the BECM still sees the charge wake-up line low before it has asked for the contactors to close. Ford's TSB 18-2386 and SSM 47630 report U301D with a lit MIL after charging on cars built up to 2 Oct 2018; if it is the only BECM code, the PCM and BECM are reprogrammed together (0.5 h) under the emissions warranty. Charging is normally unaffected, but the MIL stays on until cleared.

Likely causes

BECM and PCM software judging the wake-up timing too strictly
On-board charger raising its wake-up signal late or unsteadily
High resistance in the charge wake-up wire or connector

Symptoms

  • MIL on after a charging session
  • Code is the only entry in the battery control module

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€0–200
Time0.5–1 h

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

Parts involved

wakeup circuit abattery energy control moduleon board charger

Related codes

U301AU3021P06E4P0E64U3012

References: fordservicecontent.com, static.nhtsa.gov, static.nhtsa.gov.