P0BB5Hybrid/EV Battery Voltage Sense Y Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0BB5 stands for a sense Y voltage below the plausible minimum. GM's 2016 Volt module and the 2019 battery energy control module both use 0.2 V or less for 1.4 s inside a 2 s window and flag it as Type A. Before testing, the 2019 module makes sure that no open sense line, no lost communication with the cell monitoring slave and no balancing or internal slave fault is active, and that the second protection self test is not running. The eAssist mild hybrid sets the code below 1.4 V in seven of ten samples, Type B. The likely culprits are a pinched sense wire touching a lower potential, a failed measuring channel or a cell that has really lost its charge. The driver sees a warning and reduced performance.
- What you may notice
- Hybrid or EV warning with MIL
- Noticeably reduced power
- Likely causes
- LikelyPinched sense wire Y shorting to a lower potential
- PossibleFailed measuring channel Y
- RareCell Y severely discharged
- 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: €100 – €6,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.