2016 Ram 2500 - P208E Reductant Injection Valve Stuck Clogged - No Regen

Question

Running into a wall with my 2016 Tradesman. The dash lit up with the 'Service DEF System' message and I'm currently down to the 50 miles until 5MPH max speed limp mode. I pulled the codes and got P208E indicating the injector is stuck closed. I can hear the pump priming when I cycle the key, but it doesn't seem like any fluid is actually hitting the SCR catalyst.

I live in a cold climate and we just had a deep freeze, so I'm wondering if something crystallized or if the line itself froze and cracked. The truck hasn't performed a mobile regen in over 400 miles and the soot load is climbing fast. I really need to get this sorted before it stops me on the job site tomorrow.

I tried cleaning the exterior of the DEF injector nozzle with warm distilled water because I saw some white crusty buildup, but after resetting the codes, the P208E came right back within ten minutes of idling.

WesternStarWill · Answer

✅ Confirmed fix: The DEF injector itself was internally failed but the root cause was a crystallized blockage in the supply line junction. I had to remove the injector and perform a spray volume test. Only a dribble came out.

I ended up replacing the DEF injector (Part #68239108AA) and flushing the supply line with hot distilled water to clear out the urea crystals. After the replacement, I used a high-level scan tool to perform the 'SCR Service Regen' and the 'Reset DEF Self-Learn' adaptation. The codes cleared and the limp mode countdown disappeared immediately.

CumminsCowboy · Answer

You might want to check the DEF pump pressure first using a scan tool that can perform a 'DEF System Leak Test.' If the pump isn't reaching 5 bar (about 72 psi), the injector won't spray even if it's technically functional. If you find the pressure is low, the filter in the DEF tank assembly might be plugged with crystallized urea.

2016 Ram 2500 - P208E Reductant Injection Valve Stuck Clogged - No Regen

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