P0B9DHybrid/EV Battery Voltage Sense T 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
- If sense T reports more voltage than its cell can hold, the battery controller stores P0B9D. GM documents it on several systems. The 2019 battery energy control module and the 2016 Volt set it at 4.8 V or above for 1.4 s within 2 s, Type A, and only when no open sense line fault is pending. The 16OBDG02 programme with a dedicated battery sensor module uses 4.90 V in 14 of 18 samples. The eAssist mild hybrid sets it above 4.65 V in 7 of 10 samples, Type B. In the 2012 two-mode trucks the channel is block 20, the final NiMH block, with a limit of 23 V and 15 of 20 samples, Type B. Most such readings come from wiring touching a higher potential or a faulty measuring input.
- What you may notice
- MIL and service hybrid or EV system message
- Charging power reduced
- Likely causes
- LikelySense lead T shorted to a higher cell or busbar
- PossibleMeasuring input for channel T drifting high
- RareCell or block T genuinely overcharged
- 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.