How to fix Code P0299 : Ford Ecoboost Turbocharger/ Supercharger ‘A’ Underboost Condition

How to fix Code P0299: Ford Ecoboost Turbocharger/Supercharger ‘A’ Underboost Condition

Welcome to the OBD2 fault code. We’re going to be correcting this error code, P0299, for a turbocharger under boost, and I’m going to show you one of the more common fixes and easier fixes on this particular problem. Now, there’s not just one reason to get a turbocharger under boost. It’s leakage. of pressurized air in the system. So it could be coming from anywhere post-turbocharger, which would cause this particular code to throw. But there’s one very common feature on this truck, and it’s a blow-off valve located down on the bottom of the front of the engine compartment. It’s one part, and I’ll show you why it fails. We’re going to pull out our old one and see if that’s what happened.

How to fix Code P0299 : Ford Ecoboost


If you get a tear in this particular rubber gasket here, this rubber diaphragm, then you’re going to constantly have air leakage, and you’ll have an underboost error code. I don’t know if that’s what’s wrong with our truck today, but I’ve already replaced it once, and so we went on a camping trip. I went ahead and purchased one. In the event that it happened again, the code did throw again, and so we’re going to pull our old one. Let’s take a look and see if it’s damaged. This piece is located down here. We’re going to get underneath the front of the truck from the ground. You’re going to need an eight-millimeter wrench and a pick.

The first thing is to get your little flap out of the way here. Get this little flap out of the way. Now the part. Here’s our part right here. I’m going to replace it. I have an electrical fitting that does come off. There you go. I’m going to get these eight-millimeter sockets on either side. Sorry, my hand’s in the way. Get those off. Now, back from the front of the truck, one thing you can do to help yourself is take a pick and get this air hose pulled out.


I’ll have to go underneath to get it out completely. But you can move that out of the way. It’ll give you access to your other bolt, which is actually right up in here. Right there it is. Okay, with this air moving,it does give you just enough space to get on that bolt up in there and just slowly go back around. Okay, now that you have it screwed out, this thing just pulls right out. Now let’s take a look at it and inspect it. All right, here’s our old part, which is actually a Ford Motor Company part.

Here’s our new part. It’s Amazon. Now, what you’ll look for is a tear or some sort of air leakage around this orange diaphragm. I’m actually not seeing one on this part here. But if you’re consistently getting this code and I’m not, I do get the code when I’m pulling my camper and when I really get on it to get up to speed and get a pretty heavy load. So I’m not convinced. I mean, this video is not a waste because if you’re consistently getting this under boost code, this is most likely your culprit. I’m glad to know that I’m not, but here’s what I’m going to do.


I’m going to put this part in my glove box, where I have had this one. I’m going to put this part in. We’re going to see how well it does. We’re going to see if it continues to throw the code because I’m pulling my camper again in another couple of weeks. And if for some reason I do have problems with it, I’ve always got the original back in the glove box, and I’ll reinstall it because I’m not having a consistent code with this, but just every now and then code, which means I’m probably getting some sort of boost loss somewhere else. And if it continues to be a problem, we’ll have to diagnose it. First things first, though, I am going to take this weather-stripping gasket type. out of this one.

We’re going to put it in this one. This little blue piece also comes out. It’s kind of hard to do with one hand. Got it. And I’m going to reinstall them in my new part. And there we go. We may have to straighten that up a little bit, but we’re going to run this one for a while. We’re going to store this one and see how it goes. I don’t know how well you’re going to be able to see this, but you can actually see that the part has one place to put the bolt. But the body that you’re screwing it into has two places; both of them will work; you just have to make sure you line it up and then pull it down. I still think it’s a good idea. There, it snapped in place.

couple of parts a couple of tools It’s not hard to replace, so I’ll keep you guys posted. Last thing, we’re going to erase that code and see if it comes back. There it is. now it’s still going to show and my permanent files But as I drive, the engine light will go away. Crank it up. As you can tell, it’s gone.


Through this post, I have solved the P0299 fault code. I hope you liked my tutorial. We will continue to help you like this.

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