P20EE on Jeep: How to Diagnose & Fix
SCR NOx Catalyst Efficiency Below Threshold
2 Jeep models · 2 documented issues · 1 critical · $1,200-$3,000 repair
P20EE on Jeep by model: symptoms, diagnosis and fix
The exhaust gas recirculation cooler on the 3.0L EcoDiesel can crack internally, allowing coolant to weep into the exhaust gas stream. Because the coolant boils off into the intake and exhaust, the truck loses coolant steadily with no puddle on the ground; owners report topping off repeatedly while dealers chase a phantom external leak. The coolant combines with soot to varnish the intake ports and EGR valve, causing driveability faults and NOx-related emissions codes. Some cases mimic a head gasket failure with combustion gas detected in the coolant.
Common Symptoms
- Coolant level dropping with no visible external leak
- White or sweet-smelling exhaust
- Overheating or fluctuating temperature gauge
- Check engine light with EGR flow or NOx faults
- Sooty/oily residue in the intake
How to Fix
Have the cooling system pressure- and block-tested; a chemical combustion-gas test on the coolant plus a borescope of the intake confirms EGR cooler leakage rather than a head gasket. The repair is EGR cooler replacement (frequently with the EGR valve and an intake cleaning) and a coolant system flush. Owners report replacements as early as 30k-40k miles under the emissions/powertrain warranty, so document coolant top-offs early.
Sources for this issue (3)
A DEF/SCR warning or reductant-system DTC on a 2014-2016 Grand Cherokee EcoDiesel does not prove that the complete DEF tank has failed. FCA documentation shows materially different causes and remedies within this model range: one defined 2015 population received PCM software and a fluid-level reset for reductant codes, while a separate, narrowly defined 2015 VIN/build population with manufacturing contamination required several DEF/SCR components. Eligible vehicles that received the Approved Emissions Modification may also have extended-warranty coverage for multiple DEF-system parts and diagnostic scanning. The previous card collapsed all of these paths into one integrated-tank diagnosis and published two unverified retail searches.
Common Symptoms
- Malfunction indicator lamp
- Service DEF or reductant-system warning
- A stored DEF/SCR pressure, heater, quality, or system-performance DTC
How to Fix
Record the exact DTCs, freeze-frame data, warning text, VIN, build date, and current PCM software level. Have an EcoDiesel-capable shop or Jeep dealer follow the code-specific FCA diagnostic procedure and check whether a VIN-specific service action, applicable software update, or AEM extended warranty applies. Do not infer a failed tank from P20E8, P204F, P20EE, or another reductant code alone: verify the relevant pressure, heater, level/temperature input, fluid quality/contamination, delivery line, injector, SCR catalyst, wiring, and control-software path specified for that VIN. Replace only the component the tests and applicable FCA procedure identify. No retail part is published until the failed component and VIN fitment are confirmed.
Owner tips & cautions
- TipBring the exact code, freeze-frame data, VIN, build date, and software level to diagnosis; FCA's documented remedy changes with those details.
- WarningDo not buy a complete DEF tank from the warning message alone. FCA records show that software, contamination, the tank, lines, injector, catalyst, pump, sensors, or related controls can require different service paths.
- TipFor a 2014-2016 EcoDiesel that received the Approved Emissions Modification, check the transferable extended-warranty term before paying for DEF/SCR diagnosis or covered parts.
Sources for this issue (3)
P20EE code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P20EE mean on a Jeep?
P20EE stands for "SCR NOx Catalyst Efficiency Below Threshold." This is a diesel emissions code meaning the Selective Catalytic Reduction (SCR) catalyst on Bank 1 is not cleaning up exhaust as well as it should. The SCR system sprays Diesel Exhaust Fluid (DEF) into the hot exhaust to convert harmful nitrogen oxides (NOx) into harmless nitrogen and water; NOx sensors before and after the catalyst tell the computer how well it is working. When the measured efficiency falls below the required threshold, this code sets. Because it is an emissions-protection code, it often triggers warning lights and can lead to reduced power or a speed limit (a 'derate') if left unfixed. On Jeep it is documented across 2 models: Gladiator, Grand Cherokee.
What are the most common causes of P20EE?
The most common causes of P20EE are: Poor quality, contaminated, or wrong DEF fluid, Faulty or clogged DEF injector/dosing valve, Failed upstream or downstream NOx sensor, Degraded or failed SCR catalyst, Exhaust gas temperature sensor fault affecting dosing, Exhaust or DEF line leak, DEF line/heater problems (crystallization or freezing). The specific cause varies by vehicle.
How much does it cost to fix P20EE on a Jeep?
Published repair estimates on Jeep range from $1,200 to $3,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P20EE on a different make?
View P20EE across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.