Mitsubishi Endeavor P0453: Fuel Tank Pressure Sensor/Switch Too High

Mitsubishi Endeavor uses an evaporative emission control (EVAP), system to move fuel vapors out of the fuel tank and filler neck and then sends them to engine for burning.  The fuel tank pressure is too high. P0453The engine light will turn on after the key is thrown.

The Endeavor won't fail if you have only P0453 as your trouble code.  The EVAP system controls the movement of fuel vapor.  It doesn't matter if it does that, or not. This has no impact on how your engine works.  We don't endorse ignoring this code.

The EVAP isn't always functioning.  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.  It measures the air pressure inside the tank and not the fuel pressure.  If it does so, then P0453 will be thrown.  The fuel tank pressure sensor can be found on top of the fuel tank, fuel pump or fuel level sending device.

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

P0453 Symptoms:  Mitsubishi Endeavor

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

You may only notice the fuel smell.  If your EVAP system doesn't properly remove fuel vapor it will seek other escape routes.

The causes

These are some of the most common reasons for P0453.

• Charcoal canister Clogged vent valve
• Pressure sensor in fuel tank damaged (sensor, or the wiring).
• Tank with contaminated fuel
• PCM/ECM (highly unlikely)

Diagnose P0453 with the Mitsubishi Endeavor

Diagnosing P0453 in your Endeavor 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 Endeavor’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 gas valve by driving for awhile.  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 frayed wires.  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.

What a Mechanical Engineer Will Do

• 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.  This can be heard depending on which year and model of the vehicle.

A mechanic can inspect the wiring leading to the fuel pressure sensor if the fuel tank pressure is not within the specifications.  A mechanic will inspect the wiring leading to the fuel pressure sensor and replace it if that is found.

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.

Mitsubishi Endeavor: P0453 Conclusion

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.  It's possible to fix your Endeavor.