The 2022 Jeep Grand Cherokee's 3.0L EcoDiesel uses DEF for emissions compliance. When DEF warnings appear, understanding the system helps resolve issues before speed limiting activates.
EcoDiesel DEF System
The DEF system monitors fluid quality, level, and system function. The Grand Cherokee's system is integrated with the vehicle's extensive driver information center, providing detailed status information.
Common DEF Issues
Quality Sensor Problems
The quality sensor can fail or become fouled, reporting incorrect DEF quality. P20EE indicates the system detects poor quality regardless of actual fluid condition.
DEF Crystallization
DEF can crystallize in the tank, lines, or around sensors. Crystals affect sensor readings and can block fluid flow.
Contaminated DEF
DEF contaminated with other fluids causes immediate quality warnings. The EcoDiesel system is sensitive to concentration variations.
Heater Failures
In cold weather, heater failures prevent DEF from flowing, triggering system faults even with good DEF.
Countdown to Derating
FCA/Stellantis vehicles progressively limit performance when DEF issues aren't resolved, eventually restricting speed to 5 MPH.