egr valve zero position relearn

jaysonfordtech · July 1, 2006

Ok guys I have been lurking and enjoying everyone's post for bit now, so I thought I might toss this out to you and see if you know something. I had a '04 f-350 6.0 that after egr replacement due to excessive carbon it came back with a semi related concern, so I pulled eec codes and had a p0404, p0405 that I could not explain as I had cleared the codes after the prior repair. I cycled the egr valve and had plenty of flow, engine noise change, and iat2 increased rapidly. I called hotline and was informed that the codes were my fault as I had not performed the egr relearn procedure. I asked the nice fellow on the hotline where this came from as I try to keep up on the new info from FMC about this POS engine. He informed me that this was not in print, and was from the reflash recall software change. What the hell is going on, we have a hard enough time with all the info let alone with info being withheld. Well according to the fellow I have to clear cont. dtc's, then perform a kam reset, then perform a koeo test (this is the critical part), then perform vgt relearn. I found the codes went away after this hoke poke dance, and the concern of the customer was a turbo that sticks hot after about 20 miles. I got about 29psi at 75mph. Good luck guys, this was just one more reason I am in college to get my bachelor and get the heck out of this. PS we better stock up on Toyota special tools as I can see that as soon as the asians learn to build a 1 ton, the legacy of this line of diesel engines is going to come home to roost and the blue oval will be a cheap buy for toyota to gain some manufacturing space. /forums/images/%%GRAEMLIN_URL%%/banghead.gif lol. /forums/images/%%GRAEMLIN_URL%%/banghead.gif

Jim Warman · July 1, 2006

Sorry to see your take on the engine, Jayson.... the 6.0 is a very good engine, though the control system does leave something to be desired... In all honesty, I think we can thank the EPA and Ford equally for some of this stuff....

I see that you have mixed terms in your post using EGR relearn at one point and VGT relearn at another....

The VGT map depends heavily on a properly functioning EGR system... if the EGR goes south, VGT will learn, through adaptive strategy, to compensate (this is my assumption, not a stated fact). As with any adaptive strategy, things can only be compensated for so much (look at how fuel trims change in a gasser with a vacuum leak).

I think that some adaptive strategy can change in very few key cycles while other needs a lot of running to "synchronize". I also think that we should be considering KAM resets more than we do for some of these repairs (easy for me to say now I'm straight time with perks) that we make that can influence boost or fuel curves...

FWIW, other marques are not without their concerns.. Even domestic brands are starting to get a bit heavy on assemblies built in third world sweatshops. With the way the world is going, I can see a change of some sort.....

Keith Browning · July 1, 2006

I'm not too sure or convinced that there is a specific EGR re-learn process and I would like to hear that from an engineer myself. Regardless whether we are talking about a 2003 engine or not, EGR operation and flow monitoring (Comprehensive Component Monitor) relies heavily on the MAF sensor. You must remember that EGR and VGT must have accurate intake and exhaust manifold pressure readings (inferred or actual) and a proper speed density/mass air reading. THAT is what really needs to be relearned and calculated before the EGR/VGT can be accurately controlled and monitored.

I have found that a P0404 is usually the result of restricted EGR passages around the valve and mixer, and circuit concerns with the valve. The code means that the EGR position voltage reading was higher than expected to achieve the desired flow. You said you had a P0405? The PCM saw a voltage reading from the EGR position sensor that was out of range and if that sensor is giving biased readings it must be addressed first.

P0404/P0405 & P0404/P0406 are code combinations I have seen a lot of. It usually ends up needing the manifold to be scraped and vacuumed and the valve replaced. If you see carbon venting from the holes on the outside of the valve/sensor body, it's a positive sign that the valve is defective. I have NEVER had to perform a re-learn except for an '03 that had 06E17 performed.

The interesting thing here is that you answered your own problem by eventually diagnosing a sticking turbo. Remember I mentioned that EGR and the VGT use the same data to operate? They also work together. You can close the vanes in the VGT to increase back pressure and improve EGR flow. I also have discovered by watching many data recordings that opening the EGR valve will slow down a turbo during an over boost event where the turbo is not responding to the VGTDC commands. /forums/images/%%GRAEMLIN_URL%%/eek.gif When you have no indication or obvious signs that you have a turbo issue it will drive you absolutely crazy... but I don't have to tell you that now do I? /forums/images/%%GRAEMLIN_URL%%/laugh.gif

jaysonfordtech · July 1, 2006

I wasn't mixing up my terms Jim, that's why I posted this. I had never heard of any egr learn procedure. I had just replaced the valve a few weeks prior for excessive carbon and I thought perhaps I had forgot to clear codes after my active command post repair to verify flow, so I called hotline and that is when he told me about this new procedure. I still don't know if he was feeding me a line, but I thought I could toss it out and see if you guy's had heard anything. I'm not so sure about the 6.0 being a good motor. Maybe deep down it's a good engine, perhaps as a boat anchor in about 100 feet of water. This engine launch in 2003 was the motivation I needed to get back in college and get my bachelors. I am sure I'm not the only ford tech that saw this boat heading for the iceberg and decided to head for the lifeboats.

Jim Warman · July 1, 2006

My experience with Lukewarmline is a mixed bag... Like Kieth, I haven't heard or seen anything on an EGR relearn process.. especially since EGR position is monitored. Like our PCs, these systems do a POST (power on self test) and I would almost bet the farm that EGR closed position voltage is one of the criteria measured.

This engine did lose a lot of it's bottom end response when pilot injection disappeared but it is still very powerful for it's size (remember that Ford is extracting a lot more power from it than Cornbinder is) and, for customers that avoid the trick of the week and are familiar with diesels, it is a reliable engine (in our area, at least - remembering that ours is a very "equipment" oriented area).

As for going back to college (and I don't mean to highjack your thread), I used to think that US techs and Canadian techs were pretty much lock-step.... until I saw constant references to guys leaving the trade to get a higher paying truck driving job.

This trade is heavily regulated in Canada - especially in Alberta. Do something wrong and the Tradesmans and Qualifications Branch can shut your shop down. I have two techs (nine bubble masters) that can earn $37/hr if they "make bonus". The three of us will make 6 figures each this year - I can't afford to leave this trade.

For my part, it is the challenges that new models/features that keeps me going.Hopefully, by the time we see the 6.4, I'll have a decent grasp on the 6.0.

Would I buy a current PSD? In a hearbeat if my driving situation didn't make a diesel such a poor choice.

gasgasman · July 1, 2006

Quote:

Maybe deep down it's a good engine, perhaps as a boat anchor in about 100 feet of water.

I don't think the subsea creatures want it either. /forums/images/%%GRAEMLIN_URL%%/crybaby2.gif

snw blue by you · July 4, 2006

"I found the codes went away after this hoke poke dance, and the concern of the customer was a turbo that sticks hot after about 20 miles. I got about 29psi at 75mph."

I am confused. Posted Image