P0B8EHybrid/EV Battery Voltage Sense Q Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Channel Q reporting an implausibly high voltage sets P0B8E. On the 2012 GM two-mode hybrids, where Q is NiMH block 17, the limit is 23 V for 15 of 20 samples, Type B, checked only while the 12 V system lies between 9 and 18 V. GM's lithium-ion programs work at cell level: 4.8 V or more for 1.4 s in 2 s in the 2016 and 2019 battery controllers, more than 4.90 V in 14 of 18 samples where a separate battery sense module measures, all Type A. The BAS Plus mild hybrid limit is 4.65 V. As with the other high codes of this family, wiring and measuring input are far more often to blame than the cell; a damaged harness that lets lead Q touch the next tap is a classic finding. Charging and regeneration are limited.
- What you may notice
- Regeneration and charging limited
- MIL and battery system warning
- Likely causes
- LikelyDamaged harness letting lead Q touch the next tap
- PossibleMeasuring input of channel Q reading high
- RareReal cell overvoltage after a balancing failure
- 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.