P2E72Hybrid/EV Battery Pack B Cell Thickness Sensor 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
- P2E72 means the pack B thickness sensor reports a signal below its valid floor. On a bridge-type strain gauge, the output is a small fraction of the excitation voltage that grows with strain, so losing that excitation or shorting a bridge leg to ground pulls the reading towards zero. Capacitive designs, such as a patented pressure-sensitive QTC sensor coated with indium tin oxide, depend on a measuring module that can fail the same way. LG's piezo elements in the cell gaps only output voltage under pressure, so a short across them hides real expansion. No manufacturer documents P2E72 publicly. CARB demands separate codes for low and high faults; the high side of this circuit is P2E71, pack A's low code P2E6E.
- What you may notice
- Hybrid or EV warning light
- Power or charging may be reduced as a precaution
- Likely causes
- LikelySignal line or sensor shorted to ground inside pack B
- PossibleSensor excitation or reference supply lost
- RareFault in the measuring circuit of the battery monitoring module
- 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: €150 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.