DEF Sensor

[LeslieBermudez]

Reaching out in the hopes someone in this group has experienced something similar and can provide guidance before we invest too much time and money unnecessarily. Just yesterday my husband and I started our long awaited 2-3 year cross-country journey. We have a 2019 Tiffin Phaeton 40IH diesel pusher. Two hours into our trip the DEF sensor went off and continued beeping every couple of minutes. DEF tank is full. We checked all connections and everything looks good—clean, no frayed wires, etc. Did some preliminary Google searches and understand it could be a bad sensor or contaminated DEF, or, worse yet, a more serious system malfunction. Anyone have any experience with something similar to this? Any additional insight on how to troubleshoot?

 

[workinonit]

I can't afford to walk by a Tiffin much less ride in one but I have quite a few DEF vehicles. When you say the DEF sensor went off, what exactly was the alarm?

 

[LeslieBermudez]

It is interesting...the DEF gauge in the dash reads full (the tank is full), but the low DEF sensor on the dash came on (along with the check engine and MIL lights) and is beeping. Ordered a code reader to see what more we can ascertain, but just not making sense at this time.

 

[UTTransplant]

Call freightliner 24 hour hotline to find out how to read the codes from your dash. If a PowerGlide chassis, call Tiffin. You may go into a de-rate mode with max speed of 5mph. If it is the DEF head, a higher probability if PG chassis, the part can be sent in a day or two. If FCCC it might be available at the shop.