Pontiac G8: Pontiac G8 G0453: Too high Fuel Tank Pressure Sensor/Switch

The Pontiac G8 uses an electronic vaporative emission control (EVAP), system that moves fuel vapors between the fuel tank and filler neck. They then go to the engine for burning.  If the fuel tank pressure is too high P0453The engine light will turn on after the key is thrown.

You are not at risk of your G8 breaking down if you have only P0453 as your trouble code.  The EVAP is responsible for transferring fuel vapor.  It does not matter whether it's doing this or not. The engine will still run as normal.  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.  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, 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:  Pontiac G8

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 fuel smell.  If the EVAP isn't working properly to remove the fuel vapor from the air, the system will look for other routes.

The causes

Below are the top causes of P0453.

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

Diagnostics for P0453 on the Pontiac G8

Diagnosing P0453 in your G8 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.

How to Make Your Home a Better Place

• If you happen to notice the sound of air escaping when you take your G8’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 again 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.  It can be difficult to look at the tank without dropping it.

What a Mechanical Engineer Will Do

• To determine if the sensor detects vacuum, a mechanic will take data from the fuel pressure sensor.
• You can also tell the vent valves to open or close.  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.  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 all appears to be in order, it could indicate that the PCM may not work properly.

Pontiac G8: 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 repair your G8.