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 pump that helps cool down the battery in a hybrid or electric car isn't working as well as it should.
The P1B28 code is triggered when the vehicle's control module detects that the hybrid or electric vehicle's battery coolant pump is not operating at full capacity.
The hybrid/EV battery pack relies on a coolant pump to maintain optimal temperature. If the pump is operating below expected performance, it can affect the battery's efficiency and lifespan. This code indicates a detected limitation in the pump's operation, which could be due to mechanical or electrical issues.
• Warning light on the dashboard
• Reduced vehicle performance
• Overheating of the battery pack
• Faulty coolant pump
• Electrical issues such as wiring problems
• Blockage in the cooling system
OBD-II: On-Board Diagnostics, a standardized system for vehicles to self-diagnose and report issues.
Coolant Pump: A device that circulates coolant to manage the temperature of the battery pack.
• Check for any stored codes and freeze frame data.
• Inspect the coolant pump and related wiring for damage.
• Test the coolant pump operation and check for blockages.
• Replace the faulty coolant pump.
• Repair or replace damaged wiring.
• Clear any blockages in the cooling system.
• OBD-II scanner
• Multimeter
• Coolant system pressure tester
$200 - $600
Moderate
• Toyota Prius
• Chevrolet Volt
• Nissan Leaf
• Regular maintenance of the cooling system.
• Periodic checks of the coolant pump operation.
• Ensure the cooling system is free of blockages.
Cooling System Issue
• Do not ignore the warning light; have the vehicle checked promptly.
• Avoid driving the vehicle if it shows signs of overheating.
Check with your vehicle manufacturer; cooling system components may be covered under warranty.
This code has become more common with the increase in hybrid and electric vehicle usage, highlighting the importance of battery cooling systems.
Moderate – Address promptly to avoid potential battery damage.
Ignoring this code can lead to battery damage, which may result in costly repairs and safety hazards.
• Vehicle at operating temperature
• Coolant system filled to proper level
The coolant pump is typically located near the battery pack or in the engine compartment.
Q: Can I drive with a P1B28 code?
A: It's not recommended to drive with this code as it can lead to battery overheating.
Q: How often should the coolant pump be checked?
A: It's advisable to check the coolant pump during regular vehicle maintenance intervals.
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