P0B43Hybrid/EV Battery Voltage Sense B 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
- P0B43 sets when cell voltage channel B reads higher than a lithium-ion cell can physically reach in service, so the controller blames the measurement path. GM documents the criteria for its battery energy control module: cell voltage B at 4.8 V or above for 1.4 s within a 2 s window, Type A, one trip, with open sense line, communication and balancing faults ruled out first. Beyond GM, no manufacturer documents P0B43 publicly; FCA's sister code P0B3E for channel A shows that software in the battery controller can cause such readings. CARB treats battery voltage sensors as monitored input components. Overcharged cells use separate cell voltage codes. Low, range and open faults of channel B are P0B42, P0B41 and P0B40.
- What you may notice
- MIL and hybrid warning on
- Charging or electric drive limited
- Likely causes
- LikelyOpen sense line letting the input float high
- PossibleBattery controller software misreading the channel
- RareMeasurement input of the cell monitoring chip failed
- 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.