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 a problem with the electric pump that helps move the transmission fluid. It's like if a helper in a factory isn't working properly, so the factory can't run as smoothly.
The P27A4 code is triggered when the powertrain control module (PCM) detects a low voltage or issue in the control circuit of the auxiliary transmission fluid pump B.
The auxiliary transmission fluid pump B is an electric pump that assists in circulating transmission fluid. This code indicates that the control circuit for this pump is experiencing low voltage, which may affect the pump's performance.
• Check Engine Light illuminated
• Poor transmission performance
• Unusual noises from the transmission
• Faulty auxiliary transmission fluid pump B
• Wiring issues such as damaged wires or poor connections
• Faulty control module or relay
PCM: Powertrain Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connections to the pump.
• Test the pump for proper operation.
• Repair or replace damaged wiring and connectors.
• Replace the auxiliary transmission fluid pump B if faulty.
• Replace or repair the control module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$200 - $600
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular maintenance checks on transmission components.
• Ensure proper fluid levels and quality.
• Inspect wiring and connectors periodically.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Avoid driving the vehicle if transmission issues are severe.
Check with the vehicle manufacturer for warranty coverage on transmission components.
This code has become more common with the increased use of electric auxiliary pumps in modern vehicles.
Moderate – It should be addressed soon to prevent potential transmission damage.
Driving with a faulty transmission can be unsafe. Address the issue promptly to ensure vehicle safety.
• Vehicle at operating temperature
• Transmission engaged
The auxiliary transmission fluid pump is typically located near the transmission assembly.
Q: Can I drive with a P27A4 code?
A: It's not recommended to drive for long periods with this code, as it can lead to transmission damage.
Q: How can I reset the P27A4 code?
A: The code can be reset with an OBD-II scanner after repairs are made, but it will return if the issue is not resolved.
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