P0B31
Hybrid/EV Battery D Voltage Low
The voltage of HV battery D is below the expected window. Cell-group depleted, deeply aged, or sense fault.
The voltage of HV battery D is below the expected window. Cell-group depleted, deeply aged, or sense fault.
Common causes
- high
Cells in group aged - capacity reduced
One of the most commonly reported causes for this code — check this first.
Typical part cost: $550-5500
- medium
Deep discharge event
A plausible cause — test and verify before replacing parts.
Typical part cost: $550-5500
See all causes + fix costs
Create a free Wrenchify account to unlock the rest for P0B31.
Unlock causesFree forever · No credit card
First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
Get the full step-by-step diagnosis
Create a free Wrenchify account to unlock the rest for P0B31.
Unlock diagnosisFree forever · No credit card
Related codes
See related trouble codes
Create a free Wrenchify account to unlock the rest for P0B31.
Unlock related codesFree forever · No credit card
Frequently asked questions
What does P0B31 mean?
P0B31 means "Hybrid/EV Battery D Voltage Low". It is a generic OBD-II code that points to a fault in the hybrid / ev powertrain.
What are the most common causes of P0B31?
cells in group aged - capacity reduced; deep discharge event; pack cell imbalance approaching service threshold — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.
Get the full P0B31 diagnosis for your vehicle
Year, make, model + step-by-step repair help — free plan included.