What Does the Fuel Tank Pressure Sensor Do? Location and FAQs

Reviewed by

Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on November 9th, 2023

Reading Time: 3 minutes
Summary
  • The fuel tank pressure (FTP) sensor monitors pressure to detect evaporative leaks and loose or faulty gas caps that might prevent fuel vapors from getting contained in the EVAP system.
  • The common symptoms associated with a faulty FTP sensor include an illuminated check engine light, engine stalling, and loss of power.
  • The FTP sensor is often on top of the fuel pump module.
  • While your vehicle may still run with a bad FTP sensor, avoid driving for extended periods.
  • Replacing the FTP sensor yourself is possible, but you should leave it to experts and professionals to lessen the chances of damage or malfunctions.

Within the confines of the complex world of modern engineering, different components harmoniously work together to ensure smooth operation and efficiency. Most of these components’ functions often go unnoticed, especially for those who haven’t ventured into the intricate world of automobiles.

In a time where fuel efficiency, safety, and reduced emissions are crucial, understanding what these parts do is essential for drivers. One component not often talked about is the fuel tank pressure sensor. So what exactly is it, and how does it play a pivotal role in maintaining optimal vehicle performance?

What Does the Fuel Tank Pressure Sensor Do?

The fuel tank pressure (FTP) sensor is part of the evaporative emissions or EVAP system.

It monitors pressure to detect evaporative leaks and loose/faulty gas caps that may be preventing fuel vapors from being contained in the EVAP system. Such leaks may result in decreased fuel efficiency, an increase in emissions, and decreased engine performance.

The process of detecting leaks starts with the FTP sensor monitoring the rate with which vacuum increases in the EVAP system. Then the monitor uses this information to determine the purge volume flow rate. The EVAP monitor closes the purge valve, which creates a closed system. The FTP sensor then monitors the leak-down rate.

If the rate exceeds the stored value in the PCM consecutively, the powertrain control module sets a diagnostic trouble code (DTC).

What Are the Symptoms of a Bad Fuel Tank Pressure Sensor?

The common symptoms associated with a faulty FTP sensor include an illuminated check engine light, engine stalling, and loss of power.

Note that these symptoms may be indicative of other problems. So, if your car is showing any of them, it’s best to diagnose and trace the root issue before attempting any fixes.

Illuminated Check Engine Light

A malfunctioning FTP sensor may log one or more DTCs which causes the check engine light to be activated. Examples include codes P0442, P0453, and P0455. Keep in mind that it’s possible you get any code, depending on the vehicle.

This occurs because the computer is unaware that the fuel tank pressure sensor is failing. As such, it attempts to test the system and flags any issues it encounters.

Ignition Issues

Similar to engine stalling, a malfunctioning FTP sensor also makes it difficult to start the engine because of the compromised combustion process. Ignition issues stem from incorrect readings sent from the FTP sensor to the PCM.

This could lead to a lean air-fuel mixture, meaning the volume of air is higher than the fuel. The engine will have trouble starting because of the inappropriate fuel mixture.

Where Is the Fuel Tank Pressure Sensor Located?

The fuel tank pressure sensor is often located on top of the fuel pump module, mounted on top or inside the fuel tank.

Can I Drive With a Bad Fuel Tank Pressure Sensor?

While your vehicle may still run with a bad FTP sensor, it’s not recommended to drive for extended periods. Doing so may result in pollution because the evap system might not work properly.

Can I Replace the Fuel Tank Pressure Sensor Myself?

Replacing the FTP sensor yourself is possible, especially if you have the tools and knowledge. However, it’s advised to leave it to experts and professionals to lessen the chances of damage or malfunctions.

How Much Does It Cost to Replace a Fuel Tank Pressure Sensor?

The average price of replacing an FTP sensor is between $256 and $295. The labor fee ranges from $139 to $175, while the replacement parts are priced between $118 and $120.

How Long Does It Take to Replace the Sensor?

It takes approximately two to three hours to replace the sensor with all the necessary equipment. In addition, the fuel tank has to be dropped down first before getting access to the sensor.

About The Authors
Reviewed By Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Tony Harlin is a Master Gas and Diesel Diagnostic Technician with over 18 years of experience. He works full-time at a large independent automotive shop as a driveability and repair technician working on all types of vehicles with a focus on diesels. ASE certifications include A1-A9, L1 and L2, as well as X1.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

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.

Share
Published by
CarParts.com Research Team and Anthony Harlin, ASE Certified Master Automobile Technician