Network, generic

U04C0 Invalid Data Received From Battery Management Control Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The battery management control module behind U04C0 is not always the main controller of the high-voltage battery. Mazda uses the code on the CX-90 (2024–2026) and CX-70 (2025–2026) plug-in hybrids for their backup power unit: the PCM stores U04C0:00, which Mazda describes as an internal malfunction there, often together with P143B, U3008 or U3003 and a lit hybrid system warning. Bulletin SA-030-26 traces this to the small AGM sub battery under the passenger floor and has it replaced. GM's 2024 table 24OBDG07 has only the lost-contact sibling U01BF, set by the gateway after 6.5 s without messages from a module called LIBI, Type B, and no U04C0 entry. Not the same as U0412, the invalid-data code of the battery energy control module.

Likely causes

Weak backup sub battery (Mazda CX-90/CX-70 PHEV, AGM YTZ7S)
Battery management or backup power unit internally faulty
Bus wiring or connector fault to the module

Symptoms

  • Hybrid system warning light on
  • Further codes for the backup power supply stored

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–800
Time0.5–2 h

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

Parts involved

bms

Related codes

U01BFU04B1U0412

References: static.nhtsa.gov, gsi.ext.gm.com.