U04A8Invalid Data Received From Hybrid/EV Battery Interface Control Module H
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U04A8 is the invalid-data code for interface module H. In GM's 2016 hybrid table 16OBDG02, H is the last of eight boards that the battery systems module reaches through a daisy chain; a pack of that design needs no higher letter. GM explains that a break anywhere in such a chain cuts off every board behind it, so lost contact is reported for the first board that cannot be recovered. An invalid-data code is different: if only H's frames fail the checks while A to G pass, the cause is more likely local to H, its connector or its cell inputs. No manufacturer documents U04A8 publicly. U01A7 means H is silent, U0341 a software mismatch. The driver sees a hybrid warning and may lose power.
- What you may notice
- Hybrid system warning, MIL on plug-in hybrids
- Reduced propulsion power
- Likely causes
- PossibleInterface control module H internally faulty
- PossibleConnector or lead fault at the last board of the chain
- RareFaulty cell input on board H producing impossible values
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.