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 getting a confusing signal from a sensor that helps with braking. It's like when your TV remote sometimes works and sometimes doesn't.
The P0559 code indicates that there is an intermittent problem with the brake booster pressure sensor circuit, which affects how the car's computer reads the pressure in the brake booster.
The brake booster pressure sensor is responsible for monitoring the pressure within the brake booster to ensure proper braking force. An intermittent circuit issue means that the sensor's signal is not consistently reaching the Engine Control Module (ECM), which can lead to improper braking performance.
• Check Engine Light is on
• Brake warning light may illuminate
• Inconsistent brake pedal feel
• Faulty brake booster pressure sensor
• Damaged or corroded wiring/connectors
• Poor electrical connection in the sensor circuit
Brake Booster: A device that uses vacuum pressure to help apply the brakes.
Sensor Circuit: The electrical pathway that carries signals from a sensor to the vehicle's computer.
• Scan the vehicle for codes and freeze frame data.
• Inspect the brake booster pressure sensor and its wiring for damage.
• Test the sensor's electrical connections for continuity and proper voltage.
• Replace the brake booster pressure sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Ensure all electrical connections are secure and free from corrosion.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Toyota Camry
• Honda Accord
• Ford F-150
• Regularly inspect brake system components.
• Ensure electrical connections are clean and secure.
• Perform routine vehicle maintenance.
Sensor Issue
• Do not ignore the warning lights on your dashboard.
• Have your brakes inspected by a professional if you notice any issues.
Check with your vehicle manufacturer for specific warranty coverage on brake system components.
This code has been associated with vehicles experiencing intermittent braking issues due to sensor signal disruptions.
Moderate – While the vehicle may still be drivable, braking performance could be affected. Prompt attention is recommended.
Driving with compromised braking systems can be dangerous. Ensure repairs are conducted by qualified personnel.
• Vehicle should be parked on a level surface.
• Ensure the engine is off and the ignition is in the 'on' position for testing.
The brake booster pressure sensor is typically located near the brake booster, which is usually found on the driver's side of the engine compartment near the firewall.
Q: Can I drive with a P0559 code?
A: It's possible to drive, but it's not recommended as it can affect braking performance. Have it checked as soon as possible.
Q: How do I reset the P0559 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue persists, further diagnosis is needed.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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Universal · Torque wrench
Useful when reassembly torque matters for wheel, suspension, and under-hood fasteners.
Useful when wheel, hub, or suspension hardware needs correct reassembly torque.
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Universal · Drive-on ramps
Helpful for safer access underneath the vehicle during exhaust, EVAP, and underbody inspection work.
Helpful for safer access during underbody inspection work.
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