The EVAP Pressure Sensor, also known as a Fuel Tank Pressure (FTP) Sensor is a device that measures air pressure or vacuum in the evaporative emission (EVAP) system. This sensor is typically found on top of or inside of the fuel tank.
Code P0451 is triggered when the FTP sensor signal falls outside the specified range for an extended period.
NOTE: An understanding of EVAP systems could help you address code P0451 better. Here’s a primer.
What Does the P0451 Code Mean?
The P0451 code is defined as Evaporative Emission Control System Pressure Sensor/Switch Range/Performance.
This diagnostic trouble code is set by the PCM when it detects that the Evaporative Pressure Sensor (also known as a Fuel Tank Pressure Sensor) indicates pressure change values that are not within the manufacturer-specified range. This could happen while an EVAP monitor test is being conducted and/or during the operation of a vehicle.
This code belongs to a range of related evaporative emission trouble codes which include P0450, P0452, P0453, P0454, P0455, P0456, P0457, P0458, and P0459.
What are the possible causes of the P0451 code?
Defective EVAP pressure sensor (fuel tank pressure sensor)
The P0451 code is considered one of the more straightforward trouble codes. This error code is typically set due to a faulty or failing EVAP/Fuel Tank Pressure Sensor.
Damaged wiring or poor connections in the EVAP/Fuel Tank Pressure Sensor circuit
Issues with the EVAP/Fuel Tank Pressure Sensor’s circuit can also trigger code P0451.
In rare cases, this trouble code may be erroneously set by a malfunctioning PCM in need of a software update.
Symptoms of the P0451 code
Check Engine Light will illuminate
In most cases, there are no observable or adverse symptoms that accompany this trouble code, other than an illuminated check engine light.
How to Diagnose the P0451 Code
To resolve the P0451 code, you need to determine its exact cause, which can prove challenging. If you are not confident with your DIY automotive repair skills, it’s best to leave the task to your mechanic. However, if you’re confident about your automotive knowledge, you can try watching the video below to get an idea of what diagnosis might involve:
How to Fix the P051 Code
There’s no universal solution for code P051. The repair process will vary depending on the exact cause of the issue and the vehicle’s year, make, and model. It’s always best to bring your car to a mechanic if you’re unsure about diagnosis and repair.
If you think you have enough DIY experience to resolve the issue, it’s highly recommended that you still use online repair manuals to guide you through the repair process. You should also consider investing in an ALLDATA single-vehicle subscription, which should help you clear the P0451 code and give you more information on other repairs you may have to do on your car in the future.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.