Hyundai Accent P0453: Too high Fuel Tank Pressure Sensor/Switch

Hyundai Accent employs an evaporative exhaust control system (EVAP). This allows fuel vapors to be moved from the fuel tank and fuel filler neck to reach the engine, where they are burned.  The fuel tank pressure is too high. P0453The engine light will turn on after the key is thrown.

Your Accent will not fail if the sole trouble code you have is P0453.  Fuel vapor is transferred by the EVAP system.  It doesn't matter if it does that, or not. This has no impact on how your engine works.  This code is not to be ignored.

The EVAP system does not work all the time.  It uses a  valve to open and close the system to release fuel vapor into the engine to be burned off.

It is the fuel tank pressure sensor that detects excessive pressure.  This sensor measures air pressure within the tank. It does not measure fuel pressure.  When it does, the P0453 signal is sent.  The fuel tank pressure sensor, also known as the fuel pump pressure sensor, is usually located on top of your gas tank or fuel pump.

The opposite of this code is P0452, which is thrown whenever the system pressure is too low.

P0453 Symptoms:  Hyundai Accent

This code is usually not associated with any symptoms.  The check engine light will illuminate (that’s why you’re here).

One thing you might notice is the smell.  If the EVAP isn't working properly to remove the fuel vapor from the air, the system will look for other routes.

There are many causes

Below are some more frequent causes of P0453.

• Charcoal canister Vent valve, clogged
• Pressure sensor in fuel tank damaged (sensor or wiring).
• Damaged fuel tank
• PCM/ECM (highly unlikely)

Diagnostics P0453 for the Hyundai Accent

Diagnosing P0453 in your Accent can be challenging if you don’t have a scan tool that is capable of reading the fuel pressure sensor data or capable of commanding the vent valve to open and close.

Here are some things you can do at home

• If you happen to notice the sound of air escaping when you take your Accent’s gas cap off, that is a telltale sign that the vent valve is bad, or the charcoal canister is bad(it’s pressure leaving the gas tank).  You can open the cap by driving for awhile.  It’s hard to notice the sound when you’re at a noisy gas station.
• Examine the wiring connecting to the fuel pressure sensor. If it is damaged or frayed, you should inspect it.  If it isn’t then the only way to really diagnose it is with a professional mechanic’s scanner.  This is difficult because you may need to remove the tank from your vehicle to be able to examine it.

How a mechanic will do it

• To determine if the sensor detects vacuum, a mechanic will take data from the fuel pressure sensor.
• The vent valve will be opened and closed by them.  You can also hear the engine running depending on your vehicle's year.

A mechanic can inspect the wiring leading to the fuel pressure sensor if the fuel tank pressure is not within the specifications.  The fuel pressure sensor must be replaced if it is not working as expected.

If the vent valve is on and the pressure sensors are fine, the charcoal canister needs to be replaced.  If the vent valve doesn’t come on, it will need replacement in order to clear P0453.

If it looks good, the PCM could have a problem.

Hyundai Accent: P0453

That’s pretty much it.  While there are only a couple of common things that’ll cause P0453, there it can be tough to diagnose it without the right equipment.  It’s not going to leave you stranded on the side of the road either.  You'll be able to fix your Accent.