P0BA1 code meaning
Hybrid/EV Battery Voltage Sense U Circuit Low
Powertrain system Generic code P0Bxx codes Check engine light
What P0BA1 means
P0BA1 is stored when sense U reads close to zero. GM's lithium-ion controllers of the 2016 Volt and ELR and of 2019 treat 0.2 V or less over 1.4 s in a 2 s window as a Type A fault, provided no open sense line, lost slave communication or balancing fault is already active. The 16OBDG02 programme with its own battery sensor module uses under 0.20 V in 14 of 18 samples. GM's eAssist mild hybrid applies a much higher limit of 1.4 V in 7 of 10 samples, Type B. The two-mode NiMH trucks have no channel U. A short in the sense lead or a failed measuring input is the most likely finding.
P0BA1 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0BA1
- MIL and EV or hybrid system warning
- Propulsion power limited
Common causes of P0BA1
- Most likelySense lead U shorted towards ground or a lower cell
- PossibleDead measuring input for channel U
- Less likelyCell U internally shorted or deeply discharged
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 uWiring harnessBms
What each part of P0BA1 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. |
| A1 | The exact fault in that area. |
What to do next
- Note P0BA1 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 P0BA1
What does P0BA1 mean?
P0BA1 means "Hybrid/EV Battery Voltage Sense U Circuit Low". P0BA1 is stored when sense U reads close to zero. It is a generic code, so it means the same on every make.
Is it safe to drive with P0BA1?
Drive gently and only to a workshop. With P0BA1 the car can go into limp mode (reduced power) to protect itself.
Will P0BA1 fail an emissions test?
Yes, it can. P0BA1 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 P0BA1 to fix?
Difficulty: workshop only. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will P0BA1 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.