P0B9CHybrid/EV Battery Voltage Sense T 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
- P0B9C signals that sense T reads too low. On the 2012 two-mode trucks this is block 20, and because no block 21 exists the low test there looks at block 20 alone: below 2 V in 15 of 20 samples, Type B, while channels R and S each need their upper neighbour to read low as well. GM's lithium-ion controllers from the 2016 Volt to 2019 work with 0.2 V or less for 1.4 s within 2 s, Type A, the 16OBDG02 programme with under 0.20 V in 14 of 18 samples, and the eAssist mild hybrid with 1.4 V in 7 of 10 samples, Type B. Open sense line faults are evaluated first. For the driver the result is a warning and reduced power until the cause is repaired.
- What you may notice
- MIL and hybrid warning
- Reduced power, engine may not shut off on hybrids
- Likely causes
- LikelySense lead T shorted to ground or a lower potential
- PossibleWeak or discharged NiMH block 20 on two-mode packs
- RareFailed measuring input for channel T
- 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.