Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the electric pump that helps move the transmission fluid in your car. It's like when a pump in a fish tank stops working, and the water doesn't move around like it should.
The P27A2 code indicates that the control circuit for the auxiliary transmission fluid pump B is open, meaning there's a break or disconnection in the electrical circuit.
An auxiliary transmission fluid pump is used to maintain hydraulic pressure and fluid flow within the transmission system, especially in hybrid or electric vehicles. The 'B' designation refers to a specific pump circuit. An open circuit means there is a break in the electrical pathway, preventing the pump from operating.
• Transmission overheating
• Poor transmission performance
• Illuminated check engine light
• Faulty auxiliary transmission fluid pump B
• Damaged wiring or connectors in the pump circuit
• Blown fuse related to the pump circuit
OBD-II: On-Board Diagnostics, a standardized system in vehicles for diagnosing and reporting vehicle issues.
Transmission: A system in a vehicle that transmits power from the engine to the wheels.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or disconnection.
• Check the fuse related to the pump circuit.
• Repair or replace damaged wiring or connectors.
• Replace the faulty auxiliary transmission fluid pump B.
• Replace any blown fuses.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Toyota Prius
• Ford Fusion Hybrid
• Chevrolet Volt
• Regularly inspect wiring for wear and tear.
• Ensure proper maintenance of the transmission system.
• Avoid harsh driving conditions that may stress the transmission.
Electrical Circuit Issue
• Do not ignore the check engine light.
• Seek professional diagnosis if unsure.
• Avoid driving the vehicle excessively until repaired.
Check with your vehicle manufacturer; this repair may be covered under powertrain or emissions warranty.
This code has become more common with the increase in hybrid and electric vehicles that use electric pumps for transmission fluid circulation.
Moderate – While the vehicle may still operate, prolonged driving can lead to transmission damage.
Driving with a malfunctioning transmission pump can lead to safety issues and potential legal liabilities if the vehicle fails on the road.
• Vehicle in operation
• Transmission at operating temperature
The auxiliary transmission fluid pump is typically located near the transmission assembly, often mounted externally for easy access.
Q: Can I drive with a P27A2 code?
A: It's not recommended to drive for extended periods, as it may cause transmission damage.
Q: How do I reset the check engine light after fixing the issue?
A: Use an OBD-II scanner to clear the code, or disconnect the battery for a few minutes.
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