P05F2 trouble code on my 2015 RAM 1500 Ecodiesel

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New Member
Jul 29, 2020
Truck Year
Here I was on Saturday heading from So. Calif. to Austin, TX hauling a U-Haul 6x12 trailer to move my Daughter back home. Get to San Bernardino and I get the check engine light. Pull over and use my scanner and get trouble code P05F2 which reads "DTC definitions not found! Please refer to vehicle service manual". I ignore it for now and continue on as I took vacation time to haul my daughter back home. Then I get the message in the middle of my dash: "Engine Will Not Restart in 200 Mi Service DEF See Dealer". Now I worry. Stop off at Walmart, get more DEF even though I had put in 2.5 Gal. 2 days ago. Continue driving. Then the message that says same thing but now says 150 Mi. Get off freeway and head for home as my GPS says I am 100 miles from home right now. Heading there and as I am driving, the message pops up again at 100 Mi before Not Restart, and it stays on with the countdown going one mile less for each mile closer to home. Reach home, tranfer everything from truck to my 2005 Cadillac SRX that gets 12 mpg hauling that trailer, and I am doing 58 mph all the way to get as much mpg as I can. Now I have time to post this and get some advise and know what is best to do besides visit a dealership when I get home and have time to see about my poor RAM.


New Member
Nov 30, 2019
New Jersey
Truck Year
Code: P05F2 Definition: REDUCTANT PUMP SUPPLY VOLTAGE CIRCUIT STUCK OFF Description:When the Diesel Exhaust Fluid (DEF) system is in pressure control mode, the Powertrain Control Module (PCM) activates the DEF Supply Pump to refill the lines. As the lines fill, the pressure builds to the set point. When the pressure reaches the set point, the PCM turns on the DEF Injector to bleed air out of the Pressure Line. Each time the injector is turned off, the PCM monitors the amount of time it takes for the pressure to rise back to the set point to determine when all of the air is bled out of the line. The PCM will illuminate the MIL light immediately after the diagnostics runs and fails and diesel exhaust fluid injection into the after treatment system is disabled.Cause: