Attention: TDR Forum Junkies I recently had a rather "interesting" commute between four dealerships in three days to limp my 2016 3500 single rear wheel short bed with the P20E8 error one thousand miles to a dealer where I needed to be anyway, which was only successful due to a few very helpful suggestions here. It seems that there are a few things one must know as an owner of these trucks, and this is definitely one of them. There were some comments regarding making a "sticky" for this issue since it is a common occurrence. I do not know how to do that, but hopefully this helps someone else.
Situation: You are driving and the EVIC shows the dreaded "Service DEF See Dealer" message.
- If this is a new issue, you should get a 150 mile countdown until your vehicle is crippled. If you need to drive significantly less than that to get to your destination, no problem. Go where you planned to go, within reason (it might not be a good time to go off-roading or to a very rural campground with no cell phone service), and then seriously plan your next moves. This will most certainly involve visiting one or more dealerships.
- If you need to drive significantly more than 150 miles, you must plan in advance (at least somewhat). There are three actions that will cause your vehicle to be crippled and governed to 5 miles per hour maximum once that countdown has elapsed: fueling the vehicle, idling for more than one hour, and shutting off the engine. Your strategy should be as follows:
Common issues that cause this problem (from easy to near impossible to fix):
- Running out of DEF.
- Poor choice of DEF, contamination, or other issues.
As many may be aware, new DEF pumps cannot currently be obtained. If a dealer has one in stock, it may have the same issues as the pump that just failed. In my particular case, my truck has been in the shop for about 1.5 weeks now. The dealer found a new pump that was in stock at another dealer literally on the other side of the country, installed it, and upon testing it the new pump was already dead. Now the dealer has supposedly located a second new pump. We are awaiting shipping, but I am concerned that it may suffer the same fate. In my case this truck was new-to-me five months ago, and I have been driving about 2-3k miles per month in it without any issues, until now. I have always used Blue DEF and never let the DEF tank go empty, but I have no idea what the service history was on the truck from the original dealership through 32k miles. The service tech at a dealership has said that FCA is redesigning the pump since so many have failed and a new one should be available by May. Unfortunately, another service tech at a different dealership had advised that if the problem was a DEF pump that the best fix was to "Trade it in and get another truck." At that dealership it was reported to me that they had four disabled trucks on their lot and no spare parts they could obtain to fix them.
Situation: You are driving and the EVIC shows the dreaded "Service DEF See Dealer" message.
- If this is a new issue, you should get a 150 mile countdown until your vehicle is crippled. If you need to drive significantly less than that to get to your destination, no problem. Go where you planned to go, within reason (it might not be a good time to go off-roading or to a very rural campground with no cell phone service), and then seriously plan your next moves. This will most certainly involve visiting one or more dealerships.
- If you need to drive significantly more than 150 miles, you must plan in advance (at least somewhat). There are three actions that will cause your vehicle to be crippled and governed to 5 miles per hour maximum once that countdown has elapsed: fueling the vehicle, idling for more than one hour, and shutting off the engine. Your strategy should be as follows:
- Get some good rest if you can, you will need it.
- Plan to arrive at a dealership within the range of one tank of fuel with at least a few hours before their service department closes. I also tried to avoid rush hour traffic due to the "long idle" restriction.
- Fuel up just before the countdown hits zero miles. Once it hits zero the message changes to "5 MPH Max Speed on Restart, Long Idle or Refuel". Once you see this message absolutely do not shut the engine off.
- Drive continuously on that tank of fuel directly to the dealership. Some have suggested that you can fill the tank with small amounts of fuel (a 5 gallon can at a time) without triggering the 5 MPH limit. I did not have the testicular fortitude to try it out and potentially need to wait hours for a tow, not arrive at the dealership on time, and extend the trip by yet another day.
- Have the PCM (Powertrain Control Module) re-flashed. This resets the 150 mile countdown and all of the diagnostic trouble codes. Just resetting the diagnostic trouble codes does not reset the countdown. It cost me between $200-300 each time for them to do this (some dealerships, against my specific instructions, did other things too - like regenerating the diesel particulate filter), and until they "prove that the error is caused by a defect in a part under warranty" you will be stuck for the bill. Supposedly, once it is proven that there is a defect under warranty you can argue to get reimbursed for these bills. I have not had any success yet.
- Repeat this process until you get to your destination.
- Plan to arrive at a dealership within the range of one tank of fuel with at least a few hours before their service department closes. I also tried to avoid rush hour traffic due to the "long idle" restriction.
- Fuel up just before the countdown hits zero miles. Once it hits zero the message changes to "5 MPH Max Speed on Restart, Long Idle or Refuel". Once you see this message absolutely do not shut the engine off.
- Drive continuously on that tank of fuel directly to the dealership. Some have suggested that you can fill the tank with small amounts of fuel (a 5 gallon can at a time) without triggering the 5 MPH limit. I did not have the testicular fortitude to try it out and potentially need to wait hours for a tow, not arrive at the dealership on time, and extend the trip by yet another day.
- Have the PCM (Powertrain Control Module) re-flashed. This resets the 150 mile countdown and all of the diagnostic trouble codes. Just resetting the diagnostic trouble codes does not reset the countdown. It cost me between $200-300 each time for them to do this (some dealerships, against my specific instructions, did other things too - like regenerating the diesel particulate filter), and until they "prove that the error is caused by a defect in a part under warranty" you will be stuck for the bill. Supposedly, once it is proven that there is a defect under warranty you can argue to get reimbursed for these bills. I have not had any success yet.
- Repeat this process until you get to your destination.
Common issues that cause this problem (from easy to near impossible to fix):
- Running out of DEF.
Fill the tank, drive a bit, and the error should go away but your 150 mile countdown will not reset. If the error occurs again you will be starting at whatever mileage was left before. If this does not fix the problem you may have to re-prime/ flush the pump, which can be done with a (dealer) professional-level scan tool (the process is called the "DEF Reductant Doser Pump Override Test", located under "Systems Tests", but if you have spent many thousands of dollars on the scan tool that does this you should probably know this already). I have not found a scan tool under $1,000 that can do this, and I have not considered purchasing anything more expensive than that, but please comment here if you find one.
- Clogged DEF injector or supply tube.
This can some times be cleared by just re-priming/ flushing the pump as above. Other times, it requires removal of the injector and/ or supply tube and a good cleaning.
- Faulty DEF injector.
This is apparently a relatively quick repair, unless a bolt is stuck and breaks off in the exhaust pipe.
- Poor choice of DEF, contamination, or other issues.
This might just require draining and refilling the DEF tank followed by a re-prime/ flush, or it may have destroyed some other component(s) in the process.
- Bad DEF pump.
This is the most dreaded of the problems, as it may not (as of 10/29/2020) be able to be fixed.
As many may be aware, new DEF pumps cannot currently be obtained. If a dealer has one in stock, it may have the same issues as the pump that just failed. In my particular case, my truck has been in the shop for about 1.5 weeks now. The dealer found a new pump that was in stock at another dealer literally on the other side of the country, installed it, and upon testing it the new pump was already dead. Now the dealer has supposedly located a second new pump. We are awaiting shipping, but I am concerned that it may suffer the same fate. In my case this truck was new-to-me five months ago, and I have been driving about 2-3k miles per month in it without any issues, until now. I have always used Blue DEF and never let the DEF tank go empty, but I have no idea what the service history was on the truck from the original dealership through 32k miles. The service tech at a dealership has said that FCA is redesigning the pump since so many have failed and a new one should be available by May. Unfortunately, another service tech at a different dealership had advised that if the problem was a DEF pump that the best fix was to "Trade it in and get another truck." At that dealership it was reported to me that they had four disabled trucks on their lot and no spare parts they could obtain to fix them.
