P0B3FHybrid/EV Battery Voltage Sense A Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0B3F is reserved for a cell voltage channel A that jumps or drops out briefly instead of failing steadily. No manufacturer documents P0B3F publicly. GM's 2019 tables show how the siblings on the same channel work: an open line test (P0B3B), a stuck-in-range test against the other cells (P0B3C) and fixed limits of 0.2 V and 4.8 V (P0B3D, P0B3E); an erratic test would watch for implausible jumps between samples. CARB requires battery voltage sensors of the energy storage system to be monitored as input components, with fault codes pinpointing the smallest replaceable unit. Loose connections at the cell taps or the monitoring board are the usual suspects. Hybrid power may be limited.
- What you may notice
- MIL or hybrid warning that comes and goes
- Occasional loss of electric drive or assist
- Likely causes
- LikelyLoose or cracked cell tap connection
- PossibleFretting or vibration damage at the monitoring board connector
- PossibleElectrical noise from inverter or motor coupling into the sense lines
- 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: €80 – €6,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.