Modern enhanced evaporative emissions (EVAP) systems have a monitor that performs system self-tests. That monitor seals the system, then checks for leaks and adequate purge flow. If the fuel tank pressure (FTP) sensor assigned to watch the system sends a signal with a much higher voltage than normal, the engine’s computer may set a P0453 code.
Diagnostic Trouble Code (DTC) P0453 stands for “Evaporative Emission System Pressure Sensor/Switch High.”
The FTP sensor (also known as the EVAP pressure sensor) is usually located on or inside the fuel tank. It measures the pressure (and therefore, the vacuum) inside the tank. If the sensor signal voltage exceeds a specific value for a certain amount of time, the PCM will log code P0453.
If you’re planning to fix P0453 yourself, you may read our advanced discussion about the EVAP system and how it maintains adequate purge flow for more information.
Note: The definition of code P0453 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.
There are many reasons for the FTP sensor to send an unnaturally high signal voltage. The common causes include:
You shouldn’t find it harder to drive a vehicle suffering from a code P0453 since the malfunctioning part doesn’t control any vital process. However, it’s still best to address this problem as soon as possible since a faulty FTP sensor can’t warn the PCM of any leak that may appear in the EVAP system.
This symptom serves as a heads-up about a possible code P0453:
Most people bring their vehicle to an auto repair shop for thorough diagnosis and repair once they’ve discovered a logged P0453 code. If you feel confident with your DIY car repair skills, you can track down the trouble code to its root cause and try to fix it.
Watching the following video can expand your grasp of the P0453 code and what you might need to do to diagnose it:
There’s no single way to deal with the P0453 code, which can make fixing it tricky, especially if you don’t have the necessary tools and automotive DIY knowledge. Most people leave the job to their mechanics. You can still choose to deal with it yourself, however, you’ll need some guidance.
You can use repair manuals like those from Chilton or Haynes to help you figure out what to do. You can also get a single-vehicle ALLDATA subscription, which should be useful for the P0453 code and other future fixes you may need to do on your car.
Keep in mind that different vehicle manufacturers may have different repair instructions and that a fix that works in one particular model might not work for others.
The evaporative system’s purpose is to prevent fuel vapors from escaping into the atmosphere. Fuel vapors are carried through a hose to a special charcoal canister filled with fibrous material, and periodically, engine vacuum will be applied through the canister purge solenoid to draw atmosphere through the canister, carrying the trapped vapors into the intake manifold where they travel to the combustion chamber as part of the air-fuel mix.
The ECM/PCM’s algorithms factor this small amount of fuel vapor in while calculating the mix, because it does make a difference. The times when canister purge isn’t happening is referred to by engineers as “purge free cells” for that reason.
Initially, EVAP systems only purged vapors from the canister while the vehicle was above idle, but with the birth of OBD2 enhanced EVAP systems in the late ‘90s, the canister purge valve may operate at idle. This is important to know, because if you pack your gas tank, you might get some liquid fuel in the canister, which can cause an unexpected stumble then surge at idle as unexpected amounts of heavy vapor or liquid are delivered to the intake.
For leak detection, most OBD2 systems have a vent solenoid that blocks atmosphere from entering the canister vent during leak detection cycles.
One common way leaks are detected is for the ECM/PCM to close the normally open canister vent solenoid and deliver a very slight vacuum to the entire EVAP system (including the fuel tank), then trap that vacuum and monitor the pressure via the fuel tank pressure sensor to determine if a leak is present somewhere in the system.
One common way leaks are detected is for the ECM/PCM to close the normally open canister vent solenoid and deliver a very slight vacuum to the entire EVAP system (including the fuel tank), then trap that vacuum and monitor the pressure via the fuel tank pressure sensor to determine if a leak is present somewhere in the system.
–Richard McCuistian, ASE Certified Master Automobile Technician
Note that despite the fact that this vacuum is supplied from the engine’s intake manifold through the purge valve, this is a very, very slight vacuum that is actually measured in inches of water rather than inches of mercury, which is a much stronger vacuum.
If the system cannot build enough vacuum or the vacuum drops off too quickly after it is trapped and monitored for loss, the PCM determines the system has a leak and sets a code for either a large or small leak. The system also measures how fast the pressure recovers when the canister vent solenoid is opened and will set a code if the vacuum remains trapped when it shouldn’t.
The fuel tank pressure sensor is monitored continuously for faults. It is typically a three-wire sensor with 5 volts, a signal return ground, and a signal wire with a changing voltage that reflects tank pressure.
Dealing with a triggered P0453 code due to a faulty fuel tank pressure (FTP) sensor can be frustrating. Luckily, CarParts.com offers a quick and reliable solution to get your vehicle back on track.
Our extensive selection ensures you’ll find a top-quality replacement FTP sensor that’s compatible with your vehicle. All you have to do is access our website using your mobile phone or computer. Search for the part, fill out the vehicle selection tool, and use the search filters to view sensors that fit your needs.
Moreover, with strategically located warehouses nationwide, we guarantee fast delivery of your order. You can get your new sensor in as fast as two business days, letting you clear this trouble code in no time. Should you need assistance, our dedicated support team is available round-the-clock to help you. You can contact our representatives via our toll-free hotline.
Don’t let a malfunctioning FTP sensor disrupt your driving experience. Visit CarParts.com today to find the perfect replacement and get back on the road with confidence.
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