P0B43 code meaning
Hybrid/EV Battery Voltage Sense B Circuit High
Powertrain system Generic code P0Bxx codes Check engine light
What P0B43 means
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.
P0B43 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.2 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B43
- MIL and hybrid warning on
- Charging or electric drive limited
Common causes of P0B43
- Most likelyOpen sense line letting the input float high
- PossibleBattery controller software misreading the channel
- Less likelyMeasurement input of the cell monitoring chip failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery voltage sense bWiring harnessBms
What each part of P0B43 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| B | Area: hybrid propulsion. |
| 43 | The exact fault in that area. |
What to do next
- Note P0B43 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0B43
What does P0B43 mean?
P0B43 means "Hybrid/EV Battery Voltage Sense B Circuit High". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B43?
Drive gently and only to a workshop. With P0B43 the car can go into limp mode (reduced power) to protect itself.
Will P0B43 fail an emissions test?
Yes, it can. P0B43 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0B43 to fix?
Difficulty: workshop only. A typical repair takes 0.2 to 6 hours of work. This is a job for a workshop.
Will P0B43 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.