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 is having trouble keeping the fuel supply at the right level. It's like trying to fill a cup with water, but the water keeps going below the line it's supposed to stay at.
The engine control module (ECM) is unable to maintain the fuel mixture within the expected range during closed-loop operation.
The P306E code indicates that the ECM has detected that the fuel supply control system is unable to maintain the desired air-fuel ratio. This is typically due to a fuel delivery issue or a malfunctioning fuel system component. The 'lower limit fallen below' means the fuel mixture is leaner than expected.
• Check Engine Light is on
• Poor fuel efficiency
• Rough idle or stalling
• Faulty fuel pump
• Clogged fuel filter
• Leaking fuel injectors
ECM: Engine Control Module, the computer that controls engine functions.
Air-fuel ratio: The ratio of air to fuel in the combustion mixture.
• Check for any additional trouble codes.
• Inspect the fuel pump and fuel filter for proper operation.
• Test the fuel injectors for leaks or blockages.
• Replace the fuel pump if faulty.
• Replace or clean the fuel filter.
• Repair or replace leaking fuel injectors.
• OBD-II scanner
• Fuel pressure gauge
• Multimeter
$150 - $600
Moderate
• Toyota Camry
• Ford F-150
• Honda Accord
• Regularly replace the fuel filter.
• Use high-quality fuel.
• Perform regular maintenance checks on the fuel system.
Engine Performance
• Avoid driving the vehicle until the issue is resolved to prevent further damage.
• Consult with a professional mechanic for accurate diagnosis and repair.
Check with your vehicle manufacturer for specific warranty coverage related to the fuel system.
This code has been associated with fuel system issues in various vehicle models, often related to fuel delivery problems.
Moderate – It is recommended to address this issue soon to avoid potential engine damage.
Driving with a lean fuel mixture can lead to increased emissions and potential engine damage. Ensure repairs are performed by qualified personnel.
• Engine at operating temperature
• Closed loop fuel control active
The fuel supply components are typically located along the fuel line, from the fuel tank to the engine.
Q: Can I drive my car with a P306E code?
A: It's not recommended to drive with this code active, as it can lead to engine damage over time.
Q: How can I prevent a P306E code?
A: Regular maintenance of the fuel system and using quality fuel can help prevent this code.
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