P01A4
Alternative Fuel Rail Pressure Sensor Performance
Alt fuel rail pressure sensor reading implausible.
Alt fuel rail pressure sensor reading implausible.
Common causes
- high
Sensor reading drifted
One of the most commonly reported causes for this code — check this first.
Typical part cost: $110-660
- low
Sensor element aged beyond calibration window
Less common, but worth ruling out after the more likely causes.
Typical part cost: $110-660
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P01A4 mean?
P01A4 means "Alternative Fuel Rail Pressure Sensor Performance". It is a generic OBD-II code that points to a fault in the fuel & air metering.
What are the most common causes of P01A4?
sensor reading drifted; sensor element aged beyond calibration window; sensor element contaminated by oil, soot or coolant — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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