DEF Sensor - DSS and Carry On!

[dp7]

Originally Posted by Archer2

Thanks for the info dp7. That may help clear up some confusion. The Service Bulletin is for a DEF header that is analog with a float-type level system. Since it does not use a J1939 data bus if you have any of the DEF headers mentioned in the SB then you cannot use the DSS.
I don’t know whether the flat, inline 4 pin connector always means that the header is analog because it is conceivable that at some point in the evolution of DEF systems FL could have used the same type connector on a digital header. At any rate if you have one of these it’s not likely that yours is prone to the failures that have disabled so many coaches.

Just a thought.... I wonder if the connector listed in the TSB just supplies an analog signal to drive the analog gauge on the DEF tank. Perhaps the other cable shown on the TSB exiting a module supplies a digital signal to the J1939 bus...just a thought.

[RJS123]

Just going on record that the diesel exhaust fluids, sensors, EGR’s and every other cockamamie diesel emission control device are meant for 2 things-
1-Give some relief to the environment
2-Generate a monumental amount of revenue for manufacturers of said devices and repair centers from vehicle owners.

[milly59]

Originally Posted by DrPhil

Guess I am officially the guinea pig, so I wanted to share with the forum my experience with the above. Like many of you, I have lived with angst about DEF sensor failure, so I thought I’d share my experience in the hope that it would help others worried about or experiencing the same.

On Sept. 12, 2021 I was alerted by the IRV2 forum regarding the existence of a Diesel exhaust fluid Sensor Simulator (DSS) that would allow one to temporarily bypass a defective DEF sensor and allow one to proceed to a service center avoiding a dangerous roadside situation and/or costly tow (links below). I thought that such a device might be an inexpensive insurance policy in the event of a DEF sensor failure, so I purchased the parts ($78), programed the board and assembled. Programing was much easier than I anticipated, but fashioning the cable was the tough part (tight wiring inside of a small DB9 connector). The completed device was ready on Sept. 17th, but little did I know that I was going to need the dang thing soon.

Less than 48 hours later on Sept. 19th, DEF sensor failure occurred on my 2017 DSDP 4369 on Spartan K2. This was a real shock as I had babied my DEF system filling it at every fuel fill, etc. for the last 2 years, and at the time, the DEF tank was >3/4 full. Initially the MIL, CHECK ENGINE and a solid DEF lamp came on, and fault codes 3364 DEF QUAL, 1761 DEF VOL, and 3031 DEF TEMP were observed. Shortly thereafter (15-20 min/miles of driving) fault codes 5842 SRC MON and 1569 TOR DER were also generated. Clear 25% derate was observed at the same time via my connected ScanGaugeD looking at horsepower output (typically reached 360 hp at full throttle now 265 hp). Finding a safe place to park, allow the engine bay to cool and my nerves to chill, I powered down the chassis, disconnected the DEF sensor from the chassis harness, and plugged in the DSS (anchoring it securely via zip ties). After re-powering the chassis and starting the diesel, the CHECK ENGINE and DEF lamps disappeared, but the MIL light remained. All 5 of the codes still registered in the dash system as well as the ScanGaugeD, so I used the ScanGuage to to clear. All codes cleared except 3031 DEF TEMP. I then drove the coach and verified no additional codes appeared and normal horsepower returned as well. At my next stop, I shut down the engine and restarted. This last operation cleared the final 3031 fault code.

The next, very important step was to arrange a proper, permanent repair to this temporary DSS fix. Therefore on Sept. 20th, Spartan was called, and they verified the issue as a failed DEF sensor. To my amazement, they had the part and were willing to overnight, CoachNet arranged a mobile service visit to my location, and Cummins Sales and Service in Indianapolis did the actual work in the field.

A huge thank you (acknowledgements below) to all involved that helped me deal with my DEF sensor problem in a super timely manner! I have numerous pictures that I will post soon. PM me if you have questions.

Let’s get out there RV’ing again with confidence!

DSS and Carry On!

Acknowledgements!!!
~ Mark, Vic, Rob, and others (DSS Development Team). Empowered me to temporarily fix in the field. Truly a fun experience building, programming, and deploying the DSS. I say “DSS and carry on” t-shirts/hats should be made!
~ Dave, Spartan. Had the part and was super flexible in how to address issue and ship.
~ Jacob, CoachNet. Owned my problem, and worked with Laura at Cummins and Dave at Spartan to expedite.
~ Laura, Cummins Sales and Service, Field Operations Office, Indpls. Was willing to go the extra mile to jump through hoops at Spartan and CoachNet and arrange for someone to get to my location quickly.
~ Rob, Cummins Field Service Tech. Awesome repair! What a gentleman!

Original article describing the DSS: https://www.rvtravel.com/def-sensor-...und-rvt-1017b/
DSS Build (Uno R2 ATMega256o version - parts for Arduino Due unavailable): https://defsim.myervin.com/using-an-...-def-simulator

Hello Dr Phil i also assembled my board...hope i won t need to use it...i have a quick question...what was your total cost to have the def head...and have it installed...i called Spartan they told me they will not sell any def heads unless we are stalled somewhere and they told me cost is around $1500...and that they are at gen 7 in stock...can you tell us what was your total expense for this ordeal...thank you very much

[Archer2]

RJS123, Good thought but I am pretty sure that the 3 wires coming from the sensor are +12v, GND and (analog) data signal. The other two wires are almost certainly for an electric heater in the DEF line.

[JerryP]

I have a 2020 Tiffin 33AA with a Cummins ISB 6.7 engine on a Freightliner XCH chassis. These use the 2350 controller. The wiring schematics indicate that it uses the CAN bus to communicate. I have heard that one of the developers of the DSS have used it on the 6.7. I’m mainly concerned about what connector is used on my DEF head & engine. Some people say it may be different than the Spartan. Does anyone know what connector and its pin out is used on my RV?

[Archer2]

Hi JerryP, the quickest way would be to just go to your coach, find the DEF tank and follow the wiring that comes out of the top of the sensor (header) for a foot or two and you will find the connector. You may have to cut a wire-tie to get enough cable slack. I have no idea where your tank is located or how difficult it would be to access. But if you think you might need to use the DSS in the future it would be way better to figure out where/what the connector is, and how to disconnect and reconnect it now than trying to do it on the side of the road, in the dark, while it’s raining! Take pictures from as many angles as you can get because that might help to identify the connector part number as well as the wiring pinout.

[milly59]

Hello Dr Phil
My question was how much did it cost you to buy the replacement DEF head from Spartan and have it installed...how much was this ordeal? i know how much costs to build the sensor replacement i did built one...i was just trying to find out how much Spartan sold the new head gen7 and have it installed? thank you everybody
I called Spartan to try to get a spare head in case and they would not sell one unless i would be stuck on the side of the road somewhere...i have a 2017 Aspire 44

[R.Wold]

Originally Posted by milly59

Hello Dr Phil
My question was how much did it cost you to buy the replacement DEF head from Spartan and have it installed...how much was this ordeal? i know how much costs to build the sensor replacement i did built one...i was just trying to find out how much Spartan sold the new head gen7 and have it installed? thank you everybody
I called Spartan to try to get a spare head in case and they would not sell one unless i would be stuck on the side of the road somewhere...i have a 2017 Aspire 44

Since your emissions warranty is still in effect it wouldn’t cost anything for parts and labor. Maybe not even the tow. Just the hazards, extreme inconvenience, and logistical difficulties of being unexpectedly derated A spare DEF head seems to run between $900 and $1200 depending on the variables. Installation can be handled by anyone with average automotive mechanical skills, and the codes should clear after several ignition cycles. If you were paying for labor you could expect a charge for around 2 hours, even though its about a half-hour job.

[Calpop45]

2018 Newmar DS with just over 33k miles. Spartan chassis, K2. After months of worry about the infamous DEF Sensor issue, we joined the club 600 miles from home on a tightly scheduled trip. Spartan didn’t recognise the trouble code, but assured me it was “not a DEF issue” and to continue our trip. With an abundance of caution, we stopped at a nearby Cummins dealer, who diagnosed a DEF head failure. Another call to Spartan by the Cummins tech resulted (after some runaround) in a repair order. So now we’re sitting in a Cummins parking lot, on a Friday, hoping for the best on Monday. I’m a bit disappointed with Spartan, how is it that they don’t recognize their own chassis diagnostics?
On a positive note, the Cummins dealer in Elko, NV, deserves more than five stars for helping a stranded traveler! Great people! I just hope we can quickly resolve the issue.

[pvcampbell]

Originally Posted by DrPhil

...After re-powering the chassis and starting the diesel, the CHECK ENGINE and DEF lamps disappeared, but the MIL light remained. All 5 of the codes still registered in the dash system as well as the ScanGaugeD, so I used the ScanGuage to to clear. All codes cleared except 3031 DEF TEMP. I then drove the coach and verified no additional codes appeared and normal horsepower returned as well. At my next stop, I shut down the engine and restarted. This last operation cleared the final 3031 fault code.

I'd like to go back to this description by the OP relating to clearing the codes. If a ScanGaugeD is required to clear the codes in order to make the DSS installation effective, then in addition to building the device, I'd need to spend another ~$140 to buy the code scanner.

Is that a correct assumption?

[flyboy013]

Originally Posted by pvcampbell

I'd like to go back to this description by the OP relating to clearing the codes. If a ScanGaugeD is required to clear the codes in order to make the DSS installation effective, then in addition to building the device, I'd need to spend another ~$140 to buy the code scanner.



Is that a correct assumption?

The answer to your question is best answered here:

https://defsim.myervin.com/faq

See the “I built the DEF Simulator and hooked it up, but not all my fault codes have cleared and the MIL (Malfunction Indicator Lamp) is still on, what do I do?” question

[ekim]

Originally Posted by milly59

i called Spartan they told me they will not sell any def heads unless we are stalled somewhere and they told me cost is around $1500...and that they are at gen 7 in stock...can you tell us what was your total expense for this ordeal...thank you very much

I recently heard that Tiffin was backed up 100 sensors (100 people stuck in route waiting for sensors). **If this is true**, things are getting worse, not better. I imagine Spartan is in a similar situation. Getting a spare seems like something that's still pretty far out there. Getting a sensor that will last 5 years seems very unlikely too.

Rather than press Spartan for a Shaw sensor, why not press them for a **non Shaw** solution. Do you really want for fork over $600-$1,500 every year or two for a Shaw sensor once you are out of warrantee? I'm sure a replacement sensor will come with a "parts only" 90 day warrantee or something similar. To make matters worse, every year as they put more faulty sensors into the market the problem worsens.

In a few years many of us will be out of warranty, does anyone think that once we're placed in line behind new coaches and the thousands of in service coaches getting warranty sensors that we'll be able to get parts easily?

Also, imagine that Shaw and the chassis manufacturers are going to try to recoupe the costs for this debacle. What's a good way for them to do it? Reduce the cost (eg quality) and jack up the prices of these sensors for out of warrantee customers. Since there's no competition, they can basically do whatever they want.

If we don't have multiple vendors for these sensors then we're setting ourselves up for continued problems down the road. PLEASE hound your chassis manufacturer to put a priority on having a multi-vendor solution for these sensors. I'm sure they know it's something they need to pursue. If customers start hounding them then the bean counters might let them put resources into developing a better supply chain..... This is what will ultimately be the best thing for us.

Multiple vendors competing on quality and cost - what a concept :-)

[flyboy013]

I’ve been thinking about replacing the DEF tank drain plug with a screw in combination temperature and pressure transducer. The pressure portion would be used to measure the quantity of fluid in the DEF tank just as is done for fresh and waste tanks. The transducer would be connected to the DSS device such that the DSS would then report actual fluid temperature and level to the ECM. The only thing that would be missing would be the quality sensor, but I’m willing to forgo that for now. The DSS could become a viable permanent alternative to the failing DEF heads.

[DrPhil]

Originally Posted by milly59

Hello Dr Phil i also assembled my board...hope i won t need to use it...i have a quick question...what was your total cost to have the def head...and have it installed...i called Spartan they told me they will not sell any def heads unless we are stalled somewhere and they told me cost is around $1500...and that they are at gen 7 in stock...can you tell us what was your total expense for this ordeal...thank you very much

Unfortunately I don't know how much the senor costs nor the cost of the labor to remove and replace. Mine was a warrantee claim.