P0B23 is the general fault for the voltage of hybrid/EV battery A, the first of up to four sub-batteries or energy stores (A to D) that the battery controller evaluates separately; which physical unit carries the letter is up to the manufacturer. The code says that the measured voltage of this unit no longer fits the expected value, without the finer split into unstable (P0B24), low (P0B25) or high (P0B26). No manufacturer documents P0B23 publicly; Bentley and Stellantis bulletins only show the specific siblings. GM watches the comparable whole-pack voltage with P0ABB to P0ABD. CARB requires the voltage sensors and cells of the hybrid storage to be monitored, with fault codes that point to the smallest replaceable unit.
High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
Symptoms
- Hybrid/EV system or high-voltage battery warning on
- MIL on
- Battery power limited, less electric drive or assist
- Charging or recuperation restricted
Most likely causes
- Weak or failing cells or module in battery A
- Fault in the voltage sense leads or connectors of battery A
- Battery controller software or internal measurement fault
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0B23 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- B: Subsystem depends on the code range
- 23: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0B23?
If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
What causes code P0B23?
The most common causes are: weak or failing cells or module in battery A; fault in the voltage sense leads or connectors of battery A; battery controller software or internal measurement fault.
Related codes
- P0B24Hybrid/EV Battery A Voltage Unstable
- P0B25Hybrid/EV Battery A Voltage Low
- P0B26Hybrid/EV Battery A Voltage High
- P0B27Hybrid/EV Battery B Voltage
- P0B2BHybrid/EV Battery C Voltage
- P0B2FHybrid/EV Battery D Voltage
- P0ABBHybrid/EV Battery Pack Voltage Sense A Circuit Range/Performance
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.