P0B57Hybrid/EV Battery Voltage Sense F 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
- P0B57 stands for an implausibly high value on cell sense channel F, as opposed to P0B56 for an implausibly low one and P0B55 for a frozen value. GM uses fixed upper limits: 4.8 V or more for 1.4 s within 2 s in the battery energy control module of its lithium-ion systems (Type A, one trip), and above 23 V for block 6 in the 2012 two-mode trucks (15 of 20 samples, Type B, two trips). Both values lie clearly above what the cell or block can physically reach, so a real overcharge is not the explanation. Look for a sense lead in contact with a higher potential or for a measuring fault inside the module, and expect limited battery power and charging until then.
- What you may notice
- MIL and battery warning
- Battery charging limited
- Weaker acceleration in hybrid mode
- Likely causes
- LikelyChannel F sense lead touching a higher potential
- PossibleMeasuring input or reference fault in the 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: €50 – €5,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.