Code result
P0B28
Hybrid/EV Battery B Voltage Unstable
High severity
What it means
The voltage measurement of HV battery B fluctuates beyond the expected window. Loose connection or unstable cell.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
Loose busbar or terminal connection
highOne of the most commonly reported causes for this code — check this first.
Cell with unstable internal resistance
mediumA plausible cause — test and verify before replacing parts.
Pack cell imbalance approaching service threshold
lowLess common, but worth ruling out after the more likely causes.
Related help
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