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Thread Title Unknown Fault Code


Date Posted: Jan/17/2009 10:32 AM
Posted By: NorthstarDiesel

Hello all, I don't usually post but I read frequently, and I'd like some input if you have a moment. I have a 2006 14L in the shop with an "Unknown Fault Code" in the code description line in DDDL, but a PID 411 and FMI 13. No other codes are active or inactive recently. At this time, just a CEL, no performance issues, did standard EGR checks all ok. 411/3, 411/4, and 411/0 are all DPS faults, I took a long shot and replaced the DPS and mounting plate (also checked tubes for clogging) with no avail. Called a freind at my local Freightliner Dealer, he suspects a possible ECM problem, at this point. Anyone else run into this? Thanks.



Date Posted: Jan/17/2009 11:12 AM
Posted By: GoneFishen

Trouble shooting EGR is tricky, don't just toss in parts unless you have lots of money. Look at the DDL program and see what the engine is doing at idle, you/friend needs to really watch what is happening. I teach EGR to the knowitall kids from the tech school. Something is happening and a keen observer is needed. record a snapshop and go thru it frame by frame. I send the tech on a road test if it a bus or on the dyno if a truck. They take a snapshot and review it then. Also open DDDL, no need to have a truck there, click slose, open the drop window under help in DDDL. select DDEC 5, close warning window and the whole troubleshooting section appears.
Take a few minutes to really watch the engine at idle, then perorm a snap test and again watch what is happening. Close observation of all things on the electronic dashboard on DDDL iswhat is required, not just tossing parts.

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DDA tech for 30 years,all 2 cycle,series 60,50 mbe also.
1995 F250, 191k mi.
Lost Wages, Nv



Date Posted: Jan/17/2009 3:39 PM
Posted By: NorthstarDiesel

I agree, "Throwing parts" at an engine is not a good method of troubleshooting, and I certainly value my customer's time and money more than that! I worked between a DDC distributor and a Freightliner dealer myself for 10 years before starting my own shop, and it is amazing to me how much things can change in 2 years and how difficult it can be to keep up without access to things like G2 anymore (by the way a huge step up from the old guild). You are absolutely right, Gonefishen, these things can be very tricky, watching how the engine acts and reacts and understanding the different modes and when EGR flows is crucial. Patience and observation are key, and never has the snapshot been a more valuable troubleshooting tool! However, when you have done the EGR troubleshooting, road tested, monitored, etc, and the only problem found is simply the symptom itself, a CEL from an "unknown fault code" P411/13 that is not in the book, or DDDL troubleshooting is involved, logic would tell you that when a 411/3, 411/4, and 411/0 are all DPS related faults, perhaps that could be a thing to try, thats all. I apologize for being long winded, and I really do value your input, but what I am asking, is if any of you guys at the dealers and distributors have come across this particular "unknown fault code" 411/3?



Date Posted: Jan/17/2009 4:17 PM
Posted By: Arrrggggpower

Both of you are long winded, and obviously love to type. BUT arrrgggguing about throwing parts at it, doesnt get rid of the check engine light. So gonefishin for all the knowledge you claim to have you could have simply said "I dont know the answer." So does anyone know the answer because I have the same problem.



Date Posted: Jan/17/2009 5:20 PM
Posted By: JoeZ

Start with the obvious......inlet restriction, or exhaust back pressure. Couldn't tell you why, but I have run across both of those setting unknown codes. I had a bad turbo do the same once.

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One of the last 2 Stroke mechanics left.
44 years in the business and worked on everything from 53 series to 149 series. Winding it down now...time to move on.



Date Posted: Jan/17/2009 7:30 PM
Posted By: Arrrggggpower

Well thanks alot joez the truck I have in the shop has a staight pipe on it. Guess what will be changing Monday morning. Its not actually throwing parts at it if you have the muffler on the shelf. Is it gonefishin?





Date Posted: Jan/17/2009 7:31 PM
Posted By: Arrrggggpower

P.S. I guess 40 years is better than 30. Thanks again joez.



Date Posted: Jan/18/2009 9:47 AM
Posted By: GoneFishen

Since someone bought a sensor and this did not work, this is tossing parts. Now the DPS can log a code for what? Think and look. How about a stuck open EGR valve, how about a sticky egr valve? How about the V-POD controling the turbo? DPF is a sensor that picks up what? EGR flow. I might be long winded but I am really cheap also. You want to get it fixed? LOOK at the engine and see what is happening. AND NO WE don"t stock mufflers. we STOCK THE DPF COMPONENTS FOR THE 07 ENGINES.

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DDA tech for 30 years,all 2 cycle,series 60,50 mbe also.
1995 F250, 191k mi.
Lost Wages, Nv



Date Posted: Jan/18/2009 9:55 AM
Posted By: GoneFishen

Since you asked, what is the current software level on the engine? Also there is a hotline for questions available for dealers at Freightliner and DDC distributors. You asked, I responded. Unknown fault codes might be caused from a previous programing issue. Like dealing with an unknown, simply it is just that. clear the code and run it like %^&^& on the dyno. Pull it down to 1300 and let it sit for 20 minutes. If it is has a problem let it show itself. Otherwise go trucking. 1969 TO 2009, yes that is 40 years of fixing DDA engines.

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DDA tech for 30 years,all 2 cycle,series 60,50 mbe also.
1995 F250, 191k mi.
Lost Wages, Nv