South Llano River, Junction, TX
South Llano River, Junction, TX

Literally we were in the middle of nowhere, heading to Santa Fe, NM, enjoying the scenery and serenity of the drive. With no prior warning our check engine light suddenly came on and the following message displayed on the information panel of our RAM 3500 truck: “5MPH Max in 125 mi, Service DEF System, See Dealer.”  I’ve got Bonnie scrambling through the owner’s manual trying to determine WTH this could be as the miles in the message began counting down. And so we continued to fearfully roll down the lonely road. The dead silence in our truck was interrupted only by the continuing alarm that accompanies this message. The further we went, the more frequently the message appeared. The thoughts of hauling our 5th Wheel at 5 MPH was almost unimaginable.  But the further we traveled through the isolated countryside, the more real the situation became. Thankfully our destination in Santa Fe was within reach of the projected mileage.  But that provided little comfort as the message continued to scream at us. We made it to our RV Park, high-fived one another and started looking for the closest Dodge dealership.

Early this morning I was parked in front of the service door of the local RAM dealer (with 16 miles to spare before the truck went to 5mph limp mode) awaiting their arrival.  The service manager said they were stacked up with jobs and short a couple of mechanics but they would try to work on our truck.  I caught the dealer shuttle back to our RV and waited and waited and waited.

It took all day but our truck and its Diesel Exhaust Fluid (DEF) system is again healthy. The codes indicated contaminated DEF fluid. They had to pull the DEF tank, wash it out and clear the DEF lines  then remount and fill the tank with fresh DEF.

I’ve always used the same brand of DEF fluid since buying the truck and think I am always careful when adding fluid, so I have no idea how it got contaminated.  The service manager told me they have seen several of these situations in the last six months and he was wondering if a bad or marginal batch of DEF was being sold.

In any case, it ended well for us but we did learn the price of “emission.”  Just over four hundred bills…

Note: The dealer confirmed the 5mph max speed restriction would have been very real once the mile countdown reached zero. 

9 Comments

  1. Top speed 5 MPH! Man, would certainly make for a very long trip.

    • Yeah, Steve, but the way people drive someone would for sure rear-end us before we got too far!

      Actually, I’d park and have them both towed before I’d try to go anywhere at 5mph. It’s a federal mandate for auto manufacturers to have the vehicle disabled in some form if the DEF reactive emission control system is not functioning as designed. RAM now does the limp mode thing, a couple of years ago they made them so they just wouldn’t start after you shut them off. Ford and GM have their own methods of disablement.

  2. That is all news to me so I’ve learned something for the day. I can go back to bed. :) It is also another notice of how technology has moved along. We design these elaborate systems and then designs elaborate systems to monitor the system. It can make your head spin. Glad you made it okay and that the system worked as designed.

    • Monte, in situations like this I find myself on the Internet learning as much about the subject matter as possible — that’s my nature. I’ve certainly learned a great deal about DEF and the emission control systems diesel engines are required to have these days. I think this is partly about wanting to feel more confident and part of it is simply curiosity on my part. Even as a child I always wanted to know how things work. So with this event I’ve also learned how to check the manufacturing dates and batch numbers for the DEF I buy so as not to get old out-of-date product and how best to store it and for how long it’s shelf life is. I hope to never have to deal with this again. :-)

      It can make your head spin and the reaction, in this case, seemed severe but for cleaner air and fewer emissions I’m happy to accept a little inconvience.

  3. Cedric Canard

    You had me on the edge of my seat Brooks. Glad it all ended well :)

    • Cedric, you could have cut the tension in the air with a knife during that 100 mile “countdown ride.” Now, we can laugh about it, but not then! :-)

  4. Hmmm, thought I left a comment on this one but maybe I didn’t hit the submit button? Anyway, it was something about DEF and learning something new? Lol! Had no idea this stuff existed! Anyway, l like the photo you chose to go with this, and thanks for doing your part to support the Clean Air Act. :-)

    • Until we got this truck I didn’t know about DEF either. It’s a nuisance from an owners perspective but is suppose to be effective along with a catalytic converter in reducing Oxides of Nitrogen (NOx) emissions in diesel exhaust to nonharmful Nitrogen and water. All newer diesels are required to use it, included those big tractor trailers.

      Thanks about the photo and I did check comments and I didn’t find your previous comment.