Jeep P1404 EGR code- Would a new EGR Valve fix it? Pt1

[@John76546-x]

The scantool live data that stood out to me was the 5.0V reading for the position of the EGR valve. It seems to me any position (potentiometer reading) sensor should be .5v to 4.5v and not read the source voltage. From there I would have checked power and ground at the sensor and then checked the valve for problems.

[@SchrodingersBox]

Yes correct. You won’t see a potentiometer show the full reference voltage or complete absence of voltage. In this case clearly the potentiometer itself was faulty but of course usually it’s a circuit fault.

[@brownwrench]

4.7s are bad for broken manifold studs at the ends, which is where the egr taps in on the driver side, if I'm not mistaken. My 04 does not have EGR.

[@bas2876]

Potentio readings should be between 0.5 and 4.5 V

[@ThunderbirdRocket]

Thanks for letting us know !

[@ThunderbirdRocket]

Learning lots from you ! Thanks for the video !

[@embreesmith7613]

Bernie !!! New content. Freakin Awersum. 😀😀😀

[@marlinyoung1606]

Just because the valve was replaced does not mean the one you installed was good. Especially crap from oreillys or autozone.

[@SchrodingersBox]

Exactly. That’s why I fully tested the new one- even testing the potentiometer. The new one works properly.

[@sheerwillsurvival2064]

Another great video 👊🏻

[@Dr.AymanKamar]

Great video my friend

[@SchrodingersBox]

Thanks as always! Book came in handy here!!

[@abderrahimmark]

come on, Matt. Get already a diesel car in that garage. Get a vw tdi 😂😂 It would be fun to watch.

[@georgebonney90]

Thank you Sir

[@SchrodingersBox]

Always a pleasure George!

[@The_Noticer.]

Actually, the fuel trims make sense right? The PCM thinks its commanding the EGR, adding a known amount of exhaust back into the intake, which it would have to control for with the injection (LT fueltrim). But it's not actually getting that flow, so it corrects for it (ST fueltrim). Or am i dead wrong? :) Guess I'll find out in part2 if its actually blocked. Also, can you recommend one of those bi-directional scaltools that are DIY affordable? I'm seeing a lot of unknown brands and I'm sure a ton of them are garbage.

[@SchrodingersBox]

No I agree. The LTFT makes sense. However I was confused on why it was countered by the sTfT. The STFT should have been zero.

[@Look4u_carfixing]

Hi , why don't you make your ebook available in Amazon or eBay

[@SchrodingersBox]

I like to just keep it in the “family”.

[@davidsevor3141]

How will a ground to an egr which is power side switch affect the car's pcm? I am giving the ground to the ground side of the egr not the powerside so how will that blow up the computer 🤔

[@SchrodingersBox]

It won’t. You are giving a ground after the load so it’s fine. But ground it out before the load on the power side and it will blow the PCM because the load is power side switched.

[@davidsevor3141]

Am sorry to ask this question because i thought I've familiarise myself with the basics of electricals on this site but am thrown off by this video where he said you will burn the computer if it is a power side switch. When i give a ground to an egr with a powerside switch pcm how will that affects the pcm because after all i may even be using my test light to do that on the egr's groundside. Ground to ground shouldn't poss any problem especially when the load is connected even if it is power side switch?

[@SchrodingersBox]

It depends on which side of the load you are on. You will absolutely 100% fry a PCM supplied voltage source if you ground it directly without a load. In the example in this video that is the design of this EGR. Now if you ground it after the load OR you provide a load and ground on the power side it will be Ok.

[@davidsevor3141]

​​​@@SchrodingersBoxplease I am unable to decode or apprehen your last statement even the first one. Firstly a PCM's supplied voltage source is the battery so how can I 100% fry it am sure you meant the pcm itself and not the source. I am also not seeing the picture you are putting out clearly actually. Now the last statement says "providing a load and ground on the power side will be ok" is not clear. How can you provide ground on the power side of the load or maybe in a case one confuse the power line to that of the ground wire thereby grounding the power line while the load is being back probe?

[@SchrodingersBox]

No. A 12V source from a PCM will be from a transistor. Not the battery. If the voltage was from the battery it would go through a fuse from the circuit box, not through the pcm.

[@YourLastVictory]

This is too advanced for me to understand what’s going on especially with the graphing 😢

[@SchrodingersBox]

Yes this video assumes you know the principles from other videos that show the basics. You need to familiarize with those first.

[@YourLastVictory]

@@SchrodingersBox I’m a subscriber for your website so hopefully I’ll get there soon!

[@SchrodingersBox]

Oh by far and away that best best way to do it!!! Far and away. Might help to start with the “basic electrical for beginners” series. Also here on KZbin I have “secret of engine diagnostics: fuel trims” which helps understand how I verified the repair.

[@tomtke7351]

When you upgrade your intro you'd please me to remove the catvin pain screams to be replaced with a cat's heavy purr... I get the need for a cat but being a cat lover I cringe in pain to hear that cat in your intro...

[@rexisretro]

🫡

[@nickayivor8432]

Enjoy your evening with all your family around you,Schrodingers Box My mentor 👍 WHIP SMART,Schrodingers box From Nick Ayivor from London England UK 🇬🇧 ⏰️ 3.03AM Good Night 😴 🥱 🌃 🌙

[@SchrodingersBox]

Good to see you Nick! Best not start watching or you will go to bed at 4AM hahahaha

[@tomtke7351]

You seem to mock people with either learning or speech difficulties. QUIT!

[@ThunderbirdRocket]

You don’t know Matt do ‘ya ? He’s a very principled guy . This I can assure you .

[@SchrodingersBox]

“Who have”. Not “with”. The way you say it, the insinuation is that I have learning or speech difficulties that I leverage for mocking people which is totally untrue.

[@SchrodingersBox]

“Who have”. Not “with”. The way you say it, the insinuation is that I have learning or speech difficulties that I leverage for mocking people which is totally untrue.

[@abderrahimmark]

come on, Matt. Get already a diesel car in that garage. Get a vw tdi 😂😂 It would be fun to watch.

[@SchrodingersBox]

Hahahaha I do get asked this daily especially from European viewers. There are so few diesels here where I am. I know nothing about diesels and it would be a disaster. I tried one time a few years ago to diagnose I check engine light on a diesel and I concluded it must have had a bad MAP sensor because it wasn’t measuring engine vacuum at idle. It wasn’t until I got the same reading that I researched and learned diesels don’t have vacuum hahahaha.

[@crasbee]

@@SchrodingersBox That's not universally true. Some (especially more modern, but some as old as 80s) diesel engines have throttle valves, but they don't necessarily work in the same way (or with the same intention) as in gasoline engines. But even some gasoline engines don't necessarily have manifold vacuum, for example some BMWs have a throttle valve but it tends to be wide open because the amount of air getting into the combustion chamber is controlled by the VANOS system.

[@SchrodingersBox]

All the more reason I don’t do videos on diesels lol. True about the BMW- I forgot all about that!!