Cadillac Escalade P0455 Code Diagnosis

The most frequent trouble code with the Cadillac Escalade Is the Code P0455. This code is used to refer to the number given when your Escalade goes into an OBDII scanner. The code P0455 indicates that the Escalade is experiencing trouble. Leakage large It is part of the evaporative emission controller system. This code is often found with or related to P0420,P0441 and, very frequently, P0440.

Your Escalade will not be affected by P0455 immediately. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though. It's often associated with P0442. More information is available at Cadillac Escalade P0442 OBDII Cod.

Cadillac Escalade P0455 Definition

The universal OBDII code P0455 can be used to diagnose trouble codes. The code can be used regardless of the make and model of the vehicle. Technically, the code stands for:

System Gross Leak – Evaporative Emission System

The EVAP captures any fuel vapor in the fuel tank. They are then sent to the engines intake for ignition. When there is a large leak in the Cadillac Escalade’s EVAP system, it will throw the P0455 OBDII Code.

Cadillac Escalade P0455 OBDII Code Symptoms

A P0455 Code will usually not cause any symptoms except the ones listed below. Smells like gas And the service engine soon light. The slightest drop in fuel economy may also be noticeable.

Particular attention should be paid to the smell of fuel near the fuel tank or fuel filler tube.

The EVAP system is responsible for fuel vapors. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

Escalade Trouble Code P0455

You can trigger the P0455 code in Cadillac Escalade by a variety of reasons. The most frequent problems that trigger this code are:

• Evap System Hose– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. This can lead to the P0455 code. It should be checked for tears or holes. This is the main problem that can cause the code.
• Vapor Canister Purge Valve– One of the most common causes of the P0455 code is the vapor canister purge valve. It’s really easy to replace. You will need to locate and take out a few clips.
• A Faulty Canister of Charcoal– The charcoal canister is often the cause of P0455.
• Fuel Tank Sending Unit– It is possible for the gasket that attaches the fuel sending unit to the gas tank to go bad. It can lower the tank pressure, which could throw out the code.
• Fuel Cap– A bad fuel cap can cause the code to be thrown for sure. Often, you’ll get a message informing you that the fuel cap is off even when it is on. You may not get the message but a P0455. This will save you time and money.
• Fuel Filler Neck– There is often a gasket where the fuel filler neck connects with the gas tank. It is possible for this gasket to dry, particularly if vehicles spend a lot of time in dry environments. When it dries out, the fuel tank can’t hold pressure anymore.

P0455 Cadillac Escalade Diagnosis

The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Cadillac Escalade P0455. The most commonly used methods to diagnose this code are:

• The mechanic will usually check for any additional trouble codes. It is easier to diagnose problems if there are more codes. That’s because when they appear together in certain combinations, there will often only be only a few conditions that will throw any combination of codes at one time.
• The mechanic will normally determine what trouble codes are associated with P0455. Check out the EVAP System. These include the line and purge valve.
• A mechanic will examine the gas cap and verify that it is able to withstand high pressure. If you are getting a warning that your gas cap is off, even when it’s on, replacing it will more than likely clear this code.
• Monitor and check the pressure in your fuel tank.
• Following the inspections and repairs, the mechanic will conduct two more tests.
• A smoke test, and they’ll use a scan tool to confirm that the EVAP solenoids and valves are operating properly.

Here’s a pretty good video on diagnosing these leaks from Scotty Kilmer, if you are interested:

While the trouble code may state that there is a “large leak” in the EVAP system of your Cadillac Escalade, the actual leak will most likely still look rather small. The “large” really is referring to how much pressure is being lost.

Most common P0455 fixes

Below are the top Escalade P0455 fix requests:

• Replacing the gas cap
• Replacement for EVAP Line
• Replace charcoal canister
• Change the fuel tank

You should start with the gas caps and move on to the fuel tanks. This is because the gas caps are the easiest to replace and the least costly.

Here’s a great video on How to check your gas cap.

It's a good idea to try and figure out the reason your Cadillac Escalade throws the P0455 error code. We trust this helped. Please feel free to add anything below.

Do you consider P0455 to be a serious concern?

While P0455 is not going to cause the Escalade’s engine to stop running, it should not be treated lightly. There could be fuel contamination. You should pay extra attention to the level of your fuel tank and ensure that you're not leaking fuel. You should immediately take it in for repair or replacement.