Maintenance, Trips, Troubleshooting


Mother’s Day came late this year. We were supposed to pick-up our son from college on Mother’s Day, just as we had in 2015, on the hottest day of the year. This year, however, Ryan wanted to stay an extra week to spend time with some of his friends who were graduating on May 15th. Originally I had planned to stay home with Topper and Daisy, since the dogs (and me, apparently) add a layer of complication to college drop-offs and pick-ups; however, when I started to load up the E-trek with food and provisions for Karl, I decided  to invite myself and the dogs for the trip. We got a last minute reservation for doggy day care at the Pooch Hotel near Boston, and somehow we were all packed and ready to go before 6:00 p.m.

We had several stopover choices: multiple rest areas along Route 84, Cabela’s in East Hartford, but we made it all the way to the Cracker Barrel in Sturbridge, MA by 9:30 p.m. There were a few other RVs in the lot. It had been raining for most of the drive and was markedly cooler than our trip last May–in fact, we finally turned the Webasto heater on after freezing for most of the night. (We had it set for hot water production only.)

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Saturday morning the weather was clear, so after coffee and filling up with fuel, we were on our way to Boston. However, we noticed a message on the dash “Check Diesel Exhaust Fuel See Operator’s Manual” along with the “Check Engine” indicator lamp lit. After a brief freak out (me) and cursing the day we bought the E-trek (Karl), we pulled into the next gas station.  Karl remembered a tip during our initial walkthrough at the dealer regarding not letting the DEF get too low (more on this later), and had fortunately stowed a 2.5 gallon jug of Diesel Exhaust Fluid (DEF) in the rear of the E-trek. Karl added the DEF hoping that would clear the message. (It did not.) Also, since the “Check Engine” light was illuminated,  the manual suggested that “the DEF may have been contaminated, diluted or not compliant with ISO 22241.” Our first thought was when we refueled at a poorly-marked diesel fuel pump (just before leaving Sturbridge), we put regular gas in the E-trek. Furthermore, the manual warned, that

After the first message and under normal operating conditions, you can drive on for up to approximately 50 miles Then a warning tone sequence sounds and the engine can only be started another 10 times.

Needless to say, we were perplexed and tried to calculate how many times we would need to stop the engine: one start already used when we stopped to add the DEF, another to drop off the dogs, a third after loading up the E-trek Ryan’s dorm, another when we  pick-up the dogs, and so on. Suddenly ten starts seemed pretty limiting, so we decided to let the unit idle during each stopover. Furthermore, it was Sunday morning, so the likelihood of contacting Mercedes-Benz service was slim to none. There was a Mercedes-Benz dealer in Boston; however, they would not open until 11:00 a.m. and the service department was closed.


Another shock occurred when we got a text from our son asking what time we would be arriving. It was 9:00 a.m. and he was actually up and allegedly packed! We had just dropped off the dogs at Pooch Hotel, and got to his dorm at 9:30 a.m. I stayed in the idling E-trek while Karl and Ryan brought down bin after bin, many electronics, five coats, two suits, two fans, and numerous other belongings that somehow fit in his closet-sized dorm room. The last step was to mount Ryan’s bike on the new rack we had assembled and installed the day before. (We had recently purchased a new rack that could accommodate Karl’s ElliptiGO, which he has been wanting to take on one of our battlefield trips. It will hold an ElliptiGO and a regular bicycle, or two bicycles.) Forty-five minutes after arriving, we were ready to go. Now if only the E-trek would make it back to New Jersey…


Topper and Daisy were ready to nap after playing at the Pooch Hotel for a couple of hours. We had driven well over 50 miles without any sort of warning tone. We hit a bit of traffic as usual, on the Mass Pike, but overall the drive home went smoothly despite the ominous message. The “reserve fuel” light went on just as we approached our road, so we knew we were home free. Disaster averted.

Naturally Karl called Mercedes-Benz first thing Monday morning. The service technician’s initial diagnosis was that we had let the Diesel Exhaust Fluid (DEF) get too low and we would require a service appointment to reset the message using their fancy computer diagnosis system at a cost of $400 and not covered by the warranty. According to the Mercedes-Benz, the initial DEF supply should be good for 20,000 miles and we were at about 7,600 miles when the message appeared. The service technician said that idling accelerates the use of the DEF, and since we often idle the E-trek (i.e., to charge the batteries via the underhood generator), the DEF had gotten too low. Unfortunately, there is no way to check the level of DEF (as you can with oil), which is why the dealer recommended having DEF on hand.

Something still didn’t seem right–we had never gotten a message that the DEF was low, and according to the manual, there should have been two warning messages: one when the DEF was below 1.5 gallons and another when it drops below .8 gallon.   We certainly didn’t want a $400 repair bill for something that wasn’t our fault. When Karl called to cancel the appointment so we could do more research, our case escalated to a high level customer service manager to resolve this issue, so the Tuesday appointment went on as scheduled. Sure enough, the problem was not the DEF level but rather multiple fault codes that had triggered the error message:

  1. Upstream Turbo Temp Sensor faulty, needed to be replaced and reassembled
  2. AdBlue System Faults, so AdBlue (the Mercedes-Benz brand DEF) was topped off

The bottom line is that we were not at fault, so there were no charges for the service at all, although they first said they would be charging us to top off the DEF, but Karl protested and they waived that charge as well.

So you may ask why we would share this tale of woe when we are trying to find a buyer for our E-trek. After two successful trips ( the DEF message notwithstanding), we are reconsidering and feel we may regret selling the E-trek without giving it more of a chance. Even though we have not fully embraced the RV lifestyle, we do benefit greatly from having the E-trek available for our occasional weekend road trips. We could never fit all of Ryan’s college belongings in our pick-up truck–we need the E-trek to get him to and from college. It makes the drive to Boston much more pleasant when we can break it up and park overnight with our own bathroom and food supply. The E-trek gives us the most flexibility since it is all-electric and we don’t have to plug in or run a noisy generator. Plus, we do like to include the dogs in our outings–they get so excited when they see us loading up the E-trek. Finally, it continues to amaze and amuse us that we have so many issues and makes us wonder: did we jinx ourselves by using the tagline “What could possibly go wrong?”

7 thoughts on “BOSTON DEF OR DIE”

  1. glad you decided to keep the etrek!!! i enjoy reading your honest and thorough analysis of the joys and travails as a first time RVer.

  2. We had that issue with our E-trek, also. Went to several MB service places and they said they could find no problems, turned off the warning light and sent us on our way, at no charge fortunately. Finally, it happened again on our way to Cincinnati. Found a MB service department near there. Made an appointment, stopped by, began to explain the problem that we were having and, to my surprise, the service manager pulled me up short and said it is not a problem with the DEF, but a problem with how the Sprinters are brought over to the US. Apparently, there is some kind of training process they have to go through and it wasn’t being done because they were being shipped to companies like RT. The other problem he said that it wouldn’t be ready until Tuesday and today was Thursday. So we left it with them and they took us over to my in-laws, because that’s where we were heading. Much to our surprise, we got a call the next day saying the van was fixed and that the problem was not as severe as he thought. He said that he needed to replace the nitrous oxide sensor. Based on what you said, I am not sure they resolved the problem. Hopefully they did.

    1. Hi Dean, Thank you for sharing your interesting story–the plot thickens! We will definitely follow-up with Roadtrek/MB regarding this issue.

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