P0453: EVAP System → Pressure Sensor/Switch High

The vehicle's evaporative emission control (EVAP), system moves fuel vapor from its fuel tank and filler neck and then sends it to engine for burning.  The fuel tank pressure is too high P0453This will turn on the engine's check engine light.

The P0453 compound by itself is not considered a risk for breakdown.  The EVAP is responsible for transferring fuel vapor.  No matter whether it's doing this or not, the engine will still run as normal.  This code is not to be ignored.

The EVAP is sometimes not working.  To release the fuel vapor, the purge valve opens and closes the system.

It is the fuel tank pressure sensor that detects if the system pressure is too high.  If it happens, then P0453 will be thrown.  The fuel tank pressure sensor, also known as the fuel pump pressure sensor, is usually located on the fuel tank top, fuel pump, and fuel level sending units.

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

Signs

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, however, is The smell of fuel.  If your EVAP isn't properly purging fuel vapor it might find other routes.

The causes

These are some of the most common reasons for P0453.

• Charcoal canister Vent valve, clogged
• Fuel tank pressure sensor damaged (sensor or wiring).
• Damaged fuel tank
• PCM/ECM

Diagnosis

Diagnosing P0453 can be challenging if you don’t have a scan tool that is capable of reading the fuel pressure sensor data.  

How to Make Your Home a Better Place

• If you happen to notice the sound of air escaping when you open the fuel tank, that is a telltale sign that the vent valve is bad, or the charcoal canister is bad(it’s pressure leaving the gas tank).  Once you have driven for some time, turn off the engine and open the cap.  It’s hard to notice the sound when you’re at a noisy gas station.
• You should check the wiring for the fuel tank pressure sensor to see if there are any fraying or damage.  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.

The fuel tank pressure data may be out of specification. A mechanic will check the wiring to the fuel sensor.  A mechanic will inspect the wiring leading to the fuel pressure sensor and replace it if that is found.

The charcoal canister must be replaced if the vent valve is on and the pressure sensor works fine.

If the vent valve doesn’t come on, it will need replacement in order to clear P0453.

Conclusion 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.