P0B1AHybrid/EV Battery Pack Voltage Sense C Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0B1A flags pack voltage measurement C as in range but not believable. The controller compares it with a reference, usually the sum of the cell voltages or another pack voltage reading, and sets the code when the difference stays too large. No manufacturer documents P0B1A publicly. As an analogue, GM fails P0ABB on channel A once pack voltage and summed cell voltages differ by more than 12 V for 20 of 25 samples, Type A. CARB requires rationality monitoring for battery voltage sensors of hybrid storage systems. Electrical faults of channel C are P0B19, P0B1B and P0B1C. A distorted pack voltage undermines state of charge and cell protection, so power or charging is restricted.
- What you may notice
- MIL and hybrid/EV system warning on
- Implausible state-of-charge or range display
- Battery power limited, reduced electric drive or assist
- Likely causes
- LikelyDrift or calibration error of measurement channel C
- PossibleCell voltage acquisition faulty, reference sum wrong
- PossibleIncreased resistance at sense terminals
- RareBattery controller software needs an update
- 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 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.