Mitsubishi Outlander: P0453 Fuel Tank Pressure Sensor/Switch To High

Mitsubishi Outlander uses an evaporative emission control (EVAP), system that moves fuel vapors between the fuel tank and filler neck and then sends them to engine for burning.  The fuel tank pressure is too high. P0453The check engine light turns on when a, is thrown.

The Outlander won't fail to function if P0453 is the sole trouble code.  The EVAP system controls the movement of fuel vapor.  How your engine performs depends on whether it's doing this.  This code is not to be ignored.

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.  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 the 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:  Mitsubishi Outlander

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.

There are many causes

Below are the top causes of P0453.

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

Diagnose P0453 with the Mitsubishi Outlander

Diagnosing P0453 in your Outlander 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 Outlander’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 caps after 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

• The data of the fuel pressure sensor will be captured by a mechanic to determine whether it detects any vacuum.
• The vent valve will be opened and closed by them.  This can be heard depending on which year and model of the vehicle.

The fuel tank pressure data may be out of specification. A mechanic will check the wiring to the fuel sensor.  The fuel pressure sensor must be replaced if it is not working as expected.

The charcoal canister must be replaced if the vent valve turns on and the pressure sensor works fine.  If the vent valve doesn’t come on, it will need replacement in order to clear P0453.

If all appears to be in order, it could indicate that the PCM may not work properly.

Mitsubishi Outlander: 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.  Good luck fixing your Outlander!