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 fuel pressure regulator. It's like when a straw is pinched and you can't drink your soda easily. The fuel isn't flowing as it should.
The P0091 code indicates that there is a low voltage condition in the control circuit of the fuel pressure regulator 'A'. This means the regulator isn't getting enough power to function properly.
The fuel pressure regulator is responsible for maintaining the correct fuel pressure in the fuel rail. The 'A' control circuit is responsible for sending the necessary electrical signals to adjust the fuel pressure. A low voltage condition typically indicates an issue with the wiring, connectors, or the regulator itself.
• Check Engine Light is on
• Poor fuel economy
• Engine may run rough or stall
• Faulty fuel pressure regulator
• Damaged wiring or connectors in the control circuit
• Faulty powertrain control module (PCM)
Fuel Pressure Regulator: A device that maintains the proper fuel pressure in the fuel rail.
PCM: Powertrain Control Module, the vehicle's main computer that controls engine and transmission functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the fuel pressure regulator for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the fuel pressure regulator if faulty.
• Reprogram or replace the PCM if necessary.
• OBD-II scanner
• Multimeter
• Fuel pressure gauge
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular maintenance and inspection of the fuel system.
• Keep electrical connections clean and free of corrosion.
• Use quality fuel to prevent deposits.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Avoid driving long distances until the issue is resolved.
Check with your vehicle's manufacturer for specific warranty coverage on emissions-related components.
This code has been commonly reported in vehicles with high mileage or those that have had fuel system issues in the past.
Moderate – It should be addressed soon to prevent further engine performance issues.
Driving with a malfunctioning fuel pressure regulator can lead to increased emissions and potential safety risks.
• Engine running
• Fuel system under normal operating conditions
The fuel pressure regulator is typically located on the fuel rail near the engine.
Q: Can I drive with a P0091 code?
A: It's possible to drive short distances, but it's not recommended as it may lead to further engine issues.
Q: How do I reset the P0091 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is resolved, it should not return.
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