P0B3BHybrid/EV Battery Voltage Sense A Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Voltage sense A to Z and beyond are the cell or cell-group sense channels of the battery monitoring electronics, unlike the pack voltage sense codes P0ABA and P0B14 ff, which measure the whole pack. P0B3B is the circuit code for channel A. GM uses it in the battery energy control module as an open sense line check: neighbouring cell readings differ by 1.3 V or more, or a cell reads under 36 mV with balancing on, or a splice reads over 0.1 V (bus bar 0.5 V), for 0.6 s; Type A, one trip. Ford stores P0B3B with other open-line codes on the 2019-2020 Fusion PHEV and 2023 Mach-E; Honda's 2014-2015 Accord Hybrid used it for a cell voltage sensor fault caused by inverter noise.
- What you may notice
- MIL or powertrain warning, Stop Safely Now message possible
- No start or no charging
- Fail-safe EV mode with limited speed and sudden loss of power
- Likely causes
- LikelyOpen cell sense line, splice or bus bar connection inside the pack
- PossibleIntermittent fault in the flexible printed circuit to the battery controller (Ford Mach-E)
- PossibleSensor software misreading inverter noise, fixed by update (Honda)
- RareInternal failure of the traction battery requiring pack replacement (Ford Fusion PHEV)
- 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 – €8,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.