Here is a truly NEW development in the DEF failures

[Flyboy]

Thank you Archer. I am completely in agreement. I am not pro trying to circumvent the system or somehow delete it, however, a device like this that could move you to the nearest help is truly a wonderful idea. Like I said, put it in the drawer and forget about it until you need it. Like others, I will be waiting to see and understand more. You have been very helpful to all of us on this thread.

[Archer2]

Hey Dave (RealNiceTent) your post about your brother's truck breakdown reminds me to make a point again. There are lots of potential emissions systems breakdowns. Some have nothing to do with the DEF tank and sensors and some of them do. The thing we are discussing addresses one very specific failure. There is no way to know what your brothers problem was or whether it was what we are talking about. The only thing this device can help with is if your DEF sensors have failed completely and are sending no data and the ECM has set 3 very specific codes. if your brother didnt have all three or had some different codes or a mixture of the two this thing is not for him. Once again, this is not a DELETE DEVICE. You will still need to keep good DEF in the tank and plenty of it. If you let it run dry you will have a derate almost immediately and you risk damaging the pump and or injectors and NOx sensors.

[brobox]

Originally Posted by Archer2

Hey Dave (RealNiceTent) your post about your brother's truck breakdown reminds me to make a point again. There are lots of potential emissions systems breakdowns. Some have nothing to do with the DEF tank and sensors and some of them do. The thing we are discussing addresses one very specific failure. There is no way to know what your brothers problem was or whether it was what we are talking about. The only thing this device can help with is if your DEF sensors have failed completely and are sending no data and the ECM has set 3 very specific codes. if your brother didnt have all three or had some different codes or a mixture of the two this thing is not for him. Once again, this is not a DELETE DEVICE. You will still need to keep good DEF in the tank and plenty of it. If you let it run dry you will have a derate almost immediately and you risk damaging the pump and or injectors and NOx sensors.

Archer, just curious, when the 21 DEF head fail, I still had the tank level working as pictured in post #81. It may have finally quit, but I put 40 miles on the coach before the new head arrived and the 1761 code stayed inactive and the gauge continued to work. I know that is unusual, but can it happen as it did on mine?

[Archer2]

I am not 100% sure but this is what I think is going on. First, the DEF tank level is, for certain, based on data from the sensor. I think what is happening is if the head fails while the ignition is on like when you are driving down the road the ECM holds the last good data until it is refreshed once per second or so. The next time the key is cycled is when you will get the “no data” gauge inop symptom.

[brobox]

Originally Posted by Archer2

I am not 100% sure but this is what I think is going on. First, the DEF tank level is, for certain, based on data from the sensor. I think what is happening is if the head fails while the ignition is on like when you are driving down the road the ECM holds the last good data until it is refreshed once per second or so. The next time the key is cycled is when you will get the “no data” gauge inop symptom.

My 1761 came on the first time when I picked it up from the Alignment shop, then quickly went out. I drove and restarted the coach several times before taking it to Cummins, which thankfully is only 6 miles from my storage location, so I wasn't concerned with derate. My thought is there are 3 sensors, DEF Level 1761, DEF Temperature 3031, and DEF Quality 3364.
During the 40-45 miles with lots of restart tests, Nexus 102P code reader tests, road test, the DEF level remained accurate which was about 1/2 a tank and the error code never returned. Even the Nexus Code Reader didn't show a problem with the DEF level.

[SargeW]

I believe it total luck of the draw. When my sensor failed, it all happened at once, all three codes and alarming dash buzzers. The gauge jumped back and forth from 3/4 to empty, to full. Then it would stop for a few minutes and repeat. I was about 1 1/2 hours out from the campground and just kept driving. There was never a "normal" period for more than 2-3 minutes.

[voltdoc]

Originally Posted by Archer2

I am not 100% sure but this is what I think is going on. First, the DEF tank level is, for certain, based on data from the sensor. I think what is happening is if the head fails while the ignition is on like when you are driving down the road the ECM holds the last good data until it is refreshed once per second or so. The next time the key is cycled is when you will get the “no data” gauge inop symptom.

Hmm, I noticed this too, I have all three codes and when active the 4 bar led def tank gauge shows 75% even tho clearly the level sensor isn't reporting. That 75% level survives many key cycles and engine runs on my coach. 75% also happens to be the starting value for the emulator so nothing to conclude yet. My tank is probably about 3/4 full. I'll drain partially and see what happens. Also I beleive I can change the initial default level on the simulator and see if it is retained when I force the faults to reoccur. I'll take a look at this today.

[voltdoc]

Originally Posted by voltdoc

Hmm, I noticed this too, I have all three codes and when active the 4 bar led def tank gauge shows 75% even tho clearly the level sensor isn't reporting. That 75% level survives many key cycles and engine runs on my coach. 75% also happens to be the starting value for the emulator so nothing to conclude yet. My tank is probably about 3/4 full. I'll drain partially and see what happens. Also I beleive I can change the initial default level on the simulator and see if it is retained when I force the faults to reoccur. I'll take a look at this today.

So yesterday I drained about half the fluid out of my DEF tank. Before I did that my failed DEF head was reporting 3 green bars on the 4 bar DEF level display. I cycled the ignition several times (waiting 30 seconds off and about 1 min on), the level remained at 3 green bars. That in itself is confusing because my DEF head is dead and there is no data coming from it.

Anyway, after I drained some DEF, I left the bad DEF head connected, cycled the ignition on and now the DEF gauge shows one green bar. Yet it is reporting the three fault codes and no data coming from the DEF head. Strange.

So next I hook up the def simulator, fault codes go away (except for 3031 bad temperature info which on my coach I need to clear manually but that's another story), DEF level shows three green bars which is programmed into the simulator and as expected. Key off, disconnect the def simulator, connect bad DEF head. Key on, DEF level is still 3 green bars.

Key off, Key on, DEF level is now one green bar. So Archer2 was correct that the prior DEF level is retained for at least one ignition cycle.

What is strange is that even with the failed DEF head some degree of tank level is still being reported on my DEF gauge. The first bar of the gauge should turn red if the tank is empty.

In the next few days, I will drain my tank completely and put in some fresh DEF, checking the gauge at various stages to see what happens.

BTW, my old DEF fluid had a noticeable, but not overpowering ammonia smell. I had to get up close to get a whiff. It checked out at 32 on the refractometer.

[MRUSA14]

Perhaps urea naturally has an ammonia smell?

[brobox]

Originally Posted by MRUSA14

Perhaps urea naturally has an ammonia smell?

It does. Smelling a fresh jug then the DEF tank is a good comparison.

[dxg0001]

Sorry if I missed it but I unable to find instructions and/or zip files with the software this thread is talking about. I have most of the mentioned parts at hand except for the connectors. Where are those instructions, wiring diagrams, software, etc.?

Thanks,
Dan

[jwprosser]

Dan,
They will be posted when they are finished with final testing is my understanding.

JP

[Archer2]

Originally Posted by dxg0001

Sorry if I missed it but I unable to find instructions and/or zip files with the software this thread is talking about. I have most of the mentioned parts at hand except for the connectors. Where are those instructions, wiring diagrams, software, etc.?

Thanks,
Dan

Should be just a matter of days before all the info becomes accessible. Just keep your eyes peeled and watch for it.

[RonK]

I too have all parts but connector, hopefully it will arrive soon
Thanks to whoever is developing this solution!!!