Thawing Ram DEF tank

March 14, 2024
This bulletin applies to 2019-2022 Ram 2500/3500/4500/5500 trucks equipped with a 6.7L Cummins Turbo Diesel engine.

This bulletin applies to 2019-2022 Ram 2500/3500/4500/5500 trucks equipped with a 6.7L Cummins Turbo Diesel engine.

The MIL may be on with DTC P203E-00 (reductant level sensor 1 circuit intermittent erratic) set. Repeated freeze/thaw cycles of the urea tank may cause solid DEF crystals to form and settle on the focus tube, blocking the level sensor signal. Rapid temperature sings from below freezing to above freezing may cause an incomplete thaw of the DEF tank. When the vehicle is powered on, the diagnostic is enabled due to thawed DEF at the tank bottom surface, but the fluid in the center may still be partially frozen. This may be caused by the customer over-filling the DEF tank. 

Chrysler says that replacing the urea delivery module and grade vent valve (GVV) and updating the dosing control unit (DCU) software provides the fix.

Remove the DEF tank. Loosen the hose clamp on the GVV hose and remove the GVV from the DEF tank. Install the new GVV. Replace the urea delivery module with the kit P/N 68457124AD. Install the DEF tank. Refill the DEF tank to specification.

Reprogram the DCU with the latest software and clear any DTCs.

PART                                                   PART NUMBER
Urea delivery module service kit........68457124AD
Grade vent valve............................... 68621194AA
DEF 1 gallon..................................... 68035704AC

About the Author

Motor Age Staff

Motor Age has been publishing technical content for professional automotive technicians since 1899. Our writers have decades of experience and scores of ASE certifications, and they continue to teach new generations of technicians via classrooms all around the globe, as well as through the books and training manuals they've authored. 

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