New DEF Sensor Head Not Quite There

[Jackbnibble]

I have a 2019 Phaeton and I'm having an issue with MIL engine light on my dash. Called Tiffin, they asked for active codes. Gave them "ECM SPN 3364 FM 1-9". Also "ECM SPN 3031 FM 1-9 " I was told def sensor needs to be replaced, but none in stock. My concern is, can I drive this rig with these codes? Has any one had this issue and if so how did you handle it? Any comments would be greatly appreciated.

[brobox]

It's a gamble when it will derate. I asked Cummins when mine was changed a few weeks ago. They said it was up to the manufacture, in my case Spartan, where they programmed them to derate. Spartan won't say, and nobody has reported at what mileage it will derate, just that it will derate at some point.
I drove 35 miles before mine was changed without a problem. I waited 2 weeks for a DEF sensor to be delivered.

[Zarbek]

To continue to drive your RV after derate you will need to find the speed sensor on either the driveshaft or somewhere else and unplug. You will not get a speed reading on your dash, but you will be able to drive without the derate.

[Turbojack]

Originally Posted by Zarbek

To continue to drive your RV after derate you will need to find the speed sensor on either the driveshaft or somewhere else and unplug. You will not get a speed reading on your dash, but you will be able to drive without the derate.

If that is the case that will be a great work around. I will have to look into this. I was thinking the dash is getting the speed from the ECM based on the inputs of RPM, knowing what gear the transmission is in, tire size, and such, but been wrong before

[brobox]

Originally Posted by Turbojack

If that is the case that will be a great work around. I will have to look into this. I was thinking the dash is getting the speed from the ECM based on the inputs of RPM, knowing what gear the transmission is in, tire size, and such, but been wrong before

I have removed an Entegra driveshaft, they do not have a sensor

[Rollin101]

I think the speed sensor is on the output shaft of the tranny.

[Gasman 2]

Originally Posted by Rollin101

I think the speed sensor is on the output shaft of the tranny.

That’s what I was thinking. I believe the transmission’s ECU monitors both input and output shaft RPM. It may not like not seeing any output speed.....might default to low gear?? Anyone know?
Richard

[palehorse89]

The speed sensor's is Externally mounted in the Allison transmission........and communicates with the Allison TCM.

https://www.youtube.com/watch?v=zKocVH4oOwQ

[Gasman 2]

Originally Posted by palehorse89

The speed sensor's is Externally mounted in the Allison transmission........and communicates with the Allison TCM.

Yes should have said TCU and not ECU.

[palehorse89]

Originally Posted by Gasman 2

Yes should have said TCU and not ECU.

I knew exactly what you meant Gasman, they both talk to each other.......

[Zarbek]

I just had my DEF Head on my Spartan chassis replaced by a Cummins repair person. Here is what I learned from him:

Never fill your DEF tank at a truck stop. Why, because you can overfill the tank. If you overfill the tank then the computer sees that while you are driving the level is not going down and therefore there must be a problem. This causes an error code.

Always use the prepackaged DEF that is sealed. Why, because there are no contaminants in there to mess the DEF head sensor up.

Always completely empty your prepackaged DEF into the tank. Never recap and store. This can cause the water to evaporate in that tank and crystals can form. This will also screw up the DEF head sensor.

[brobox]

Originally Posted by Zarbek

I just had my DEF Head on my Spartan chassis replaced by a Cummins repair person. Here is what I learned from him:

Never fill your DEF tank at a truck stop. Why, because you can overfill the tank. If you overfill the tank then the computer sees that while you are driving the level is not going down and therefore there must be a problem. This causes an error code.

Always use the prepackaged DEF that is sealed. Why, because there are no contaminants in there to mess the DEF head sensor up.

Always completely empty your prepackaged DEF into the tank. Never recap and store. This can cause the water to evaporate in that tank and crystals can form. This will also screw up the DEF head sensor.

I have a feeling that is just what happened when I changed the DEF fluid in my tank after reading other post. There is a serious problem with the government mandate if we cannot change old DEF fluid for fresh without the sensor, at $700. having to be changed.

[billb3672]

WARNING: Check to make sure they replace the engine Cooling Fluid !!! We just had our DEF head replaced and I found that they didn't replace the engine cooling fluid (Anti-Freeze) that is lost during the installation process.

[azbuzzard]

Well we just joined the list of people waiting 7-10 days for a replacement.
Yesterday hooked up the toad, started the engine got check engine light and DEF gauge was all orange in color. Called Spartan, have to stay put until part comes. Canceled our next 2 campground reservations.