U029ALost Communication With Hybrid/EV Battery Pack Sensor Module
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- The battery pack sensor module is the electronics inside the high-voltage battery that reports pack current and voltage; many designs house it together with the main contactors. U029A means the battery or vehicle controller no longer hears from it. Stellantis documents the code in the battery pack control module of the 2024 Dodge Charger with 400 V electric drive: bulletins 08-026-25 Rev. B and 08-126-25 Rev. B reflash several modules and, if U029A stays, call for a six-minute sleep with the scan tool unplugged before a BPCM soft reset. Audi files U029A00 under address 8C for the 2025 Q5 e and the 2024 Q8 Sportback e-tron. Ford's 2014 code list shows it without the lamp flag. Lacking these values, the car may refuse to drive or charge.
- What you may notice
- Wrench or turtle symbol, reduced power
- Vehicle does not enable drive or stops charging
- High-voltage system warning in the cluster
- Likely causes
- LikelyOutdated software in the battery control module or sensor module
- PossibleCode latched after programming because the network never went to sleep
- PossibleMoisture or poor contact at the battery low-voltage connector or bus wiring
- RareBattery pack sensor module internally failed
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €0 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.