Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has detected that the voltage in one part of the hybrid or electric battery is not steady. It's like when a flashlight flickers because the battery is not working well.
The vehicle's control module monitors the voltage of the hybrid/EV battery pack. If it detects that the voltage in one of the battery sections (Battery B) is fluctuating beyond acceptable limits, it triggers this code.
The P0B28 code is set when the Powertrain Control Module (PCM) or Battery Energy Control Module (BECM) identifies an unstable voltage condition in the hybrid or electric vehicle's Battery B. This instability can be due to issues such as a failing cell, poor connections, or internal battery faults.
• Check Engine Light is on
• Reduced fuel efficiency
• Vehicle may enter limp mode
• Faulty battery cell
• Poor electrical connections
• Internal battery pack failure
PCM: Powertrain Control Module
BECM: Battery Energy Control Module
• Use a scan tool to verify the code.
• Inspect battery connections and wiring for damage.
• Test the voltage of individual battery cells.
• Clean and secure battery connections.
• Replace faulty battery cells.
• Repair or replace the battery pack if necessary.
• OBD-II scanner
• Multimeter
• Battery cell tester
$500 - $3000
Difficult
• Toyota Prius
• Chevrolet Volt
• Nissan Leaf
• Regular battery maintenance
• Avoid deep discharges
• Keep battery connections clean
Battery Performance Issue
• Have the battery checked by a professional.
• Avoid driving long distances until fixed.
Check vehicle warranty for battery coverage, as hybrid/EV batteries often have extended warranties.
This code has become more common as hybrid and electric vehicles age and battery components wear out.
High – This issue can lead to reduced vehicle performance and potential battery damage.
Operating a vehicle with a faulty battery can lead to unexpected vehicle shutdown and potential safety hazards.
• Vehicle in ready mode
• Battery at operational temperature
The hybrid/EV battery is typically located under the rear seat or in the trunk area, depending on the vehicle model.
Q: Can I drive with a P0B28 code?
A: It's not recommended to drive with this code as it can lead to further damage or reduced vehicle performance.
Q: How often should I check my hybrid/EV battery?
A: Regular check-ups are recommended during routine vehicle maintenance or if you notice performance issues.
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