Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's transmission has a small pump that helps move fluid around. This code means there's a leak in the pump, which can cause problems with how the car shifts gears.
The P277A code indicates there is a hydraulic leak in the auxiliary transmission fluid pump B, which may affect the transmission's ability to shift smoothly.
The auxiliary transmission fluid pump B is responsible for maintaining hydraulic pressure within the transmission system. A hydraulic leak in this pump can lead to insufficient pressure, causing transmission performance issues. This code is triggered when the vehicle's control module detects a leak or pressure drop in the pump B circuit.
• Harsh or delayed shifting
• Transmission slipping
• Unusual noises from the transmission
• Damaged or worn seals in the pump
• Cracked or damaged pump housing
• Faulty pump components
Transmission: A system in a vehicle that transmits power from the engine to the wheels.
Hydraulic: Operated by the pressure of a fluid.
• Check for transmission fluid leaks under the vehicle.
• Inspect the pump B for visible damage or wear.
• Use a scan tool to verify the code and check for related codes.
• Replace damaged seals in the pump.
• Repair or replace the pump housing if cracked.
• Replace faulty pump components as necessary.
• OBD-II scan tool
• Hydraulic pressure tester
• Basic hand tools
$300 - $800
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular transmission fluid checks and changes
• Inspect seals and gaskets periodically
• Avoid aggressive driving to reduce wear
Transmission System Issue
• Avoid driving the vehicle until repaired to prevent further damage.
• Consult a professional mechanic for a thorough inspection.
Check with the vehicle manufacturer for specific warranty coverage related to transmission components.
This code has been reported in vehicles with high mileage or poor maintenance history, often linked to neglected transmission fluid service.
High – Ignoring this issue can lead to significant transmission damage and costly repairs.
Driving with a malfunctioning transmission can be dangerous and may lead to further damage. Address this issue promptly.
• Vehicle at operating temperature
• Transmission in drive mode
The auxiliary transmission fluid pump B is typically located on or near the transmission housing.
Q: Can I drive with a P277A code?
A: It's not recommended to drive with this code, as it can cause transmission damage.
Q: How can I prevent this code from appearing?
A: Regular maintenance and fluid checks can help prevent this issue.
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