Hyundai won't release details for 61D004 - likely defective software at manufacture.
"may have internal cell voltage deviation"
What is likely going on here?
After a month of back-and-forth with Hyundai UK, Hyundai Group there really is no detail. And more than that, seemingly no concern about the lack of detail.
If you connect "may have internal cell voltage deviation" and "detect potential battery abnormalities" - this likely addresses cell pack voltage deviation.
This data is already provided by the BMS (7E4) 220101 since the vehicle was built. Either the data wasn't checked, or the check parameters were incorrect / insifficient.
Hyundai will not admit nor release details.
There is no "confidential intellectual property of Hyundai and its suppliers" - this is a serious safety issue that can be largely mitigated by honesty.
It's taken Hyundai 6 years to realise this.
They likely became aware of it and fixed the issue in the later model BMS. Rather than be forth comming and release details for people to check their own cell pack deviation and, if necessary, approach dealers to make warranty claims or attempt an equalizing charge they are attempting to down play what is likely a software oversight.
Hyundai's final response
1. Why was this campaign introduced?
The purpose of Campaign 61D004 is to enhance the Battery Management System's capability to detect potential battery abnormalities earlier and more reliably, thereby improving preventive protection measures.
2. What exactly has changed in the software?
The update introduces enhanced monitoring and diagnostic logic within the Battery Management System (BMS).
Key improvements include:
Expanded monitoring coverage during both driving and parked conditions.
Improved sensitivity to battery cell condition changes.
Earlier identification of potential irregularities.
Faster activation of warning and protective functions when required.
3. Which modules are updated?
The software update applies to the vehicle's Battery Management System (BMS), which is responsible for monitoring and managing the high-voltage battery system.
The BMS performs functions such as:
Battery management system
Battery cell voltage monitoring
State of Charge (SOC) & State of Health (SOH)
Fault diagnostics
The purpose of this update is to strengthen the system's ability to identify and respond to potential battery irregularities at an earlier stage.
While we are able to describe the functional improvements, we are not able to provide detailed source code, software architecture, algorithms, calibration parameters, and proprietary engineering data, as they constitute confidential intellectual property of Hyundai and its suppliers.
As such, this email constitutes our final response on this matter.