P0453 CODE: Evaporative (EVAP) Emission Pressure Sensor High Input

In case you’re not familiar with this term,  EVAP is the mechanism that allows fuel tank vapors to be directed to the engine and burnt as opposed to expelling them into the atmosphere where they’d cause harmful emissions.

The EVAP system in most vehicles has a pressure sensor, which monitors the whole process.

On occasion, the EVAP system conducts a pressure test to determine if there are any leaks in the system. It achieves this with the help of the pressure sensor.

So if the pressure goes above 4.5 volts, the sensor transmits information to the PCM signaling that the pressure is extremely high.

As in the case of the P0452 code, there are just two things that indicate your car has the P0453 trouble code. These are the illumination of the engine light and a noticeable fuel smell, although the latter happens rarely.

There are several factors that contribute to this trouble code. They include:

• Open signal wire of the fuel tank pressure (FTP) sensor
• Short to the voltage on the FTP sensor signal wire
• A faulty FTP sensor
• Unusually high pressure in the fuel tank as a result of a blockage in the EVAP purge hose or overfilled fuel tank
• Loose or damaged FTP sensor connector
• Loss of ground to the sensor

Conduct a visual inspection

Often, the greatest culprits of this trouble code are damaged or corroded wiring and unplugged sensor. Thus, the first step should be to inspect the wiring and pressure sensor of the EVAP control system.

Look for the EVAP canister underneath your car. You will find it connected to the fuel tank or as a distinct unit that has hoses extending to the fuel pump at the fuel tank. Inspect the EVAP and verify that the pressure sensor’s connector is well-seated and clipped in. The main thing you should look for on the connector and wires are signs of corrosion or wear and tear.

The next step is to disconnect the sensor and check the condition of the pins in the terminal. Ideally, they should be clean and have no traces of moisture. Check the entire wiring starting from the sensor and determine if there are any breaks on the wiring insulation. Take note that you may be forced to remove the electrical tape to inspect the wiring.

Test the output voltage

A majority of car owners prefer to have a mechanic fix issues in their autos. One of the advantages of hiring a mechanic is that they have all the required tools. Now, if you’re resolving the P0453 code on your own, you’ll need to acquire special tools to perform this test, that is, a scan tool or a multimeter.

If you’re using a multimeter, confirm that the reference wire has 5 volts, then inspect the continuity of the ground circuit. Using the multimeter, probe the sensor signal wire so that you can get a reading of the voltage. When doing this, you should have your car key in the on position but the engine shouldn’t be running. The ideal voltage reading you should get is about 3 volts.

The next step involves removing the attached hose and applying vacuum using a vacuum tester. As you do this, keep tabs on how the voltage changes on the multimeter. If the voltage changes as you apply more vacuum, this indicates that the sensor is in good working order. However, if there’s no change in the voltage, it shows that the sensor is faulty.

If you’re using a scan tool instead, the first step is to get a reading of the EVAP pressure sensor from the freeze frame data. Just as in the previous case, the key should be in the on position but the engine should be turned off. The reading you get from the EVAP pressure sensor should be in the range of 3 volts.

If the ECM is still showing the P0453 code and you’ve not gotten an unusual voltage reading- when using either the multimeter or scan tool- it’s likely that you have an intermittent issue. You’ll need to conduct a wiggle test on the wiring to verify that there’s no communication problem from the sensor to the ECM.

Wiggle the circuit and keep track of the voltage reading on your scan tool. If you notice the voltage increasing or dropping as you swing a portion of the wire, it’s possible that you have a break in the wire. So once you repair the wire, you’ll get a normal voltage reading.

P0453 is a trouble code indicating that the pressure in the evaporative emissions system is higher than normal. This can happen for several reasons such as a damaged fuel tank pressure sensor, open or shorted signal wire or a damaged sensor connector. The best solutions for this error code entail inspecting the EVAP system and testing the output voltage.