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 electricity going to a special pump in the car that helps move the transmission fluid. It's like when a toy car's battery isn't connected properly, so the car can't move.
The P0B09 code indicates that there is an issue with the electrical circuit that supplies power to the auxiliary transmission fluid pump A. This could be due to an open circuit or a problem with the supply voltage.
The auxiliary transmission fluid pump is responsible for maintaining the necessary pressure and flow of transmission fluid, especially in hybrid or electric vehicles. The P0B09 code is triggered when the vehicle's control module detects an open circuit or abnormal voltage in the motor supply circuit of this pump.
• Warning light on the dashboard
• Transmission overheating
• Poor transmission performance
• Vehicle may enter limp mode
• Faulty auxiliary transmission fluid pump
• Damaged wiring or connectors in the pump circuit
• Blown fuse or faulty relay
• Control module failure
Auxiliary Transmission Fluid Pump: A pump that helps circulate transmission fluid, especially in hybrid or electric vehicles.
Open Circuit: A break in the electrical circuit preventing current flow.
• Check for any blown fuses related to the transmission pump circuit.
• Inspect wiring and connectors for damage or corrosion.
• Test the auxiliary transmission fluid pump for proper operation.
• Use a multimeter to check for proper voltage and continuity in the circuit.
• Replace any blown fuses or faulty relays.
• Repair or replace damaged wiring or connectors.
• Replace the auxiliary transmission fluid pump if it is faulty.
• Reprogram or replace the control module if necessary.
• Multimeter
• OBD-II scanner
• Wiring repair tools
$200 - $800
Moderate
• Toyota Prius
• Chevrolet Volt
• Ford Fusion Hybrid
• Regularly inspect wiring and connectors for wear and tear.
• Ensure proper maintenance of the transmission system.
• Avoid driving through deep water which can damage electrical components.
Electrical Circuit Issue
• Do not ignore the warning light; have the vehicle checked as soon as possible.
• Avoid driving the vehicle extensively until the issue is resolved to prevent further damage.
Check with your vehicle manufacturer; this issue may be covered under the powertrain or emissions warranty.
This code is more common in hybrid or electric vehicles due to their reliance on electric auxiliary pumps.
Moderate – Address the issue soon to avoid potential transmission damage.
Driving with a malfunctioning transmission pump can lead to safety issues and should be addressed promptly.
• Vehicle in park with engine running
• Transmission at normal operating temperature
The auxiliary transmission fluid pump is typically located near the transmission, often mounted on or near the transmission housing.
Q: Can I drive with a P0B09 code?
A: It's not recommended to drive with this code active as it can lead to transmission damage.
Q: How can I reset the P0B09 code?
A: After repairs, the code can be cleared using an OBD-II scanner. However, ensure the issue is resolved to prevent it from returning.
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