Ram DEF Freezing

This bulletin applies to 2019-2022 RAM 2500/3500/4500 vehicles equipped with a 6.7L I6 Cummins turbo diesel engine. Customers may experience a MIL on. DTC P203E-00 (reductant level sensor 1 circuit intermittent/erratic) may be set.

Repeated freeze/thaw cycles of the urea tank can cause solid DEF crystals to form and settle on the focus tube, blocking the level sensor signal. Rapid temperature swings from below freezing to above freezing can 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 is still partially frozen.

1. Loosen the hose clamp on the grade vent valve (GVV) hose and replace the GVV from the DEF tank.
2. Replace the urea delivery module with kit 68457124AD and the vent valve with P/N 68621194AA. After repairing, the DEF fluid level must be at or above the level it was when the customer brought the vehicle into the shop.
3. Refill the DEF tank.
4. Reprogram the DCU with the latest software. Clear all DTCs.