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Well, here we go, not even 20K miles in on my recently purchased used 2011Mack with an  MP8 (505,000 miles) and I get my first check engine light.

SA: 0
SPN: 4752
FMI: 7

Topped a long grade with a heavy load, check engine light comes on. All gauges read normal so I kept on truckin to get my load delivered. Truck is running fine and brought me back home. Code seems to reflect EGR or EGR cooler related issue.

My question is? Can I run this until I can conveniently schedule it into the dealer? Or am I looking at my first downtime with my MP8?
I have lots of work lined up that would really hurt to lose :(. I also don't want to risk damage to the motor or having it go into derate mode and basically stranding me.

I do NOT like these "modern" motors...not one bit.

Thank you

 

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Thank you for the terrific replies. Its very much appreciated when a guy has few places to turn for insight.

I finally caved and decided to drop out on my work for today and take it to Mack. One day`s revenue (hopefully it only be one day) isn't worth possible damage to the motor. I was going to start ripping apart the Delta P sensor and Venturi pipe myself to maybe try and clean but then came to the realization i`m out of my territory with all this emissions stuff.

I will post back what Mack finds, hopefully that will help the next person down the line.

Thanks again !

Well, a day of lost revenue and a $480.73 charge from Mack and my problem is supposedly resolved.

Macktech689 hit the nail on the head. Software Reprogram.

I dunno, help me to understand, how does software go bad?  :idunno:
I mean, the truck ran fine for months on the software as it was, why does it just up and decide that now all of a sudden the software is no good?  I just don't get it, and I guess because of that, I have very little faith in the repair.

Half a grand and not one new part? just a bunch of code.

I guess the bright side is, it was only $480. and they did get it in/out the same day! But I just don't get it! LOL

The software doesn't go bad, the updates amend the system programing so to speak. Normal thing. As for the code appearing, the long pull with the load might have been just enough for the software glitch to appear.     Paul

"OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK"  Thomas Edison

 “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’

P.T.CHESHIRE

I appreciate the explanation 41chevy, that does put it into better context for me. I guess then theoretically, as you continue to update the software, it becomes better refined and more accepting of wider ranges of operating possibilities.

Still seems funny to me though. In the past, Ive never had to amend or update my truck to do what it was built to do, pull the load. Its kind of like amending a pool to hold water! (Here`s your pool, in the future however you may need to re-teach it that it has to actually hold the water, cause it might forget its purpose)

I'm not knocking it either, just forcibly trying to move on with the "modern" times lol.

Thanks again!

Certainly a different world. In the not to distant past when I raced my 55 chevy, I'd kick the timing, maybe change jets, add or remove a carb spacer and go. Now with my Mustang  I get to sit with a lap top, check air temp, humidity and adjust anything from boost, fuel spray, shift points, different trigger points for NOX  and a zillion other things with out even popping the hood. Newer trucks are the same, some need to "learn" a new job that puts different requirements on the Computer than what it is used to, so it needs a nudge to relearn it's limits. 21st century is an entirely different game.

Edited by 41chevy
  • Like 1

"OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK"  Thomas Edison

 “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’

P.T.CHESHIRE

  • 2 months later...

Just a friendly update to this topics in hopes it might help another down the road.

It happened again, same scenario, long, hard pull with a heavy load. Just about to the top of the grade and my check engine light appears. Same code as before...

SA: 0
SPN: 4752
FMI: 7

So, after some online research, and rather than take it to Mack again, I decided to butt heads with the computer myself.

I replaced the Venturi tube and Differential Pressure Sensor and that did the trick! Its a simple, easy to do fix. Depending on your year engine, Mack (Volvo) has updated the Venturi tube and Sensor. You will need a new mounting bracket as well as a new jumper harness for the sensor. End of the day, just shy of $500 total in parts. Immediately after replacement, the code became inactive and MIL went off.

Now I might have been able to just try and clean the sensor and tube, but once I had it all out , ahhh, just replace it. If you want to try and just replace the sensor only, you might find you are forced into buying a new tube, bracket and harness as the updated sensor will not fit on the old style Venturi Tube.

As a side note, There's just something not right about getting your Mack Truck parts in a Volvo box! :unsure:

  • Like 1

There is a service bulletin on this issue I believe , it will be Monday before I can post it. Yes, software caused the issue , however if the truck was driven to long with the improper software, the EGR cooler is plugged and must be replaced .  Best case ,  with the new software the code never reoccurs . Worst case , new egr cooler . I've been told on the 2010 and up egr coolers can't be cleaned out but you never know .

On 5/16/2016 at 4:45 PM, Rockwell said:

Well, a day of lost revenue and a $480.73 charge from Mack and my problem is supposedly resolved.

Macktech689 hit the nail on the head. Software Reprogram.

I dunno, help me to understand, how does software go bad?  :idunno:
I mean, the truck ran fine for months on the software as it was, why does it just up and decide that now all of a sudden the software is no good?  I just don't get it, and I guess because of that, I have very little faith in the repair.

Half a grand and not one new part? just a bunch of code.

I guess the bright side is, it was only $480. and they did get it in/out the same day! But I just don't get it! LOL

Usually software updates extend sensor parameters or include enhancements. All the testing in the world means nothing compared to real world application.  Because of excessive warranty failures, engineering may realize that extending sensor parameters will prevent further issues. Its kind of a learn as you go thing. Many diagnostic steps require checking for new software updates. 

I was about to say, volvo d13 fix was the delta p sensor and the venturi pipe that are sooted up and or clogged. There was a updated sensor and pipe that can be installed as well. Make sure they run a complete regen as well after the repair is complete. Location: Passenger side, front above the coolant filter. Also, you might need to replace your egr at some point in the future.

I paid 146.00. Sensor. 96.00 for harness

They should make a usb backup system for these but im sure its cause they know someone will hack it somehow.

Edited by Mickey603
updated

I still would bet the cooler is on the verge of fouling again and throwing SPN 4752 FMI 7. Cooler efficiency isn't about EGR flow, it's EGR temp and the main measurement for the cooler efficiency calculation. Look at any heat exchanger calculation, it's all temps in and out of the cooler. The venturi upgrade may have moved the cooler inlet temp calculation "off center"  slightly resulting in no more MIL light. Based on comments from owner, fault occurs at high load on long pull, exactly where EGR temp problems show up. Next time light occurs, you can pull cooler and pressure wash or steam clean inside. I would even do it to the new style coolers before ever buying a new one. Another trick is to hook up small water injection system on the inlet pipe to the cooler and hit the cooler with a few minutes of water driving down the road.  One customer got tired of constantly cleaning his cooler and made the system himself. This is not much different than the factory condensation cleaning method that's in all engines. 

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