What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P109D8ABattery Management Units (BMU), Authentication FailureManufacturer communications
2Original wording in English
VOLVO
Reported code forms P109D8A
When updating the Energy Storage Control Module (ESCM) software, the truck may display fault code P109D8A – Battery Management Units (BMU), Authentication Failure.
MACK
Reported code forms P109D8A
Battery Electric Vehicle (BEV) - DTC P109D8A Following Energy Storage Control Module (ESCM) Software Update
Check vehicle applicability
14A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Mack | LRBE (ELECTRIC) | 2025 |
| Mack | LRBE (ELECTRIC) | 2024 |
| Mack | LRBE (ELECTRIC) | 2023 |
| Mack | LRBE (ELECTRIC) | 2022 |
| Mack | LRBE (ELECTRIC) | 2021 |
| Mack | LRBE (ELECTRIC) | 2020 |
| Mack | LRBE (ELECTRIC) | 2019 |
| Volvo | VNRE (ELECTRIC) | 2025 |
| Volvo | VNRE (ELECTRIC) | 2024 |
| Volvo | VNRE (ELECTRIC) | 2023 |
| Volvo | VNRE (ELECTRIC) | 2022 |
| Volvo | VNRE (ELECTRIC) | 2021 |
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.