P20C2 on 2014-2016 Jeep Grand Cherokee — Reductant Heater "C" Control Circuit Performance
1 vehicles · 1 makes
How to diagnose and fix P20C2: most-reported vehicles
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Jeep Grand Cherokee · 2014–2016
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)
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P20C2 code reference
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Frequently asked questions
What does P20C2 mean?
P20C2 stands for "Reductant Heater "C" Control Circuit Performance." A generic diesel emissions code on SCR-equipped vehicles (Ford, RAM/Cummins, GM Duramax, Mercedes, VW and many medium/heavy-duty diesels). The powertrain control module commanded the "C" diesel exhaust fluid (DEF) heater on and the measured circuit voltage or current fell outside the expected range. The letter "C" designates one of several heaters on vehicles with multiple DEF heaters - typically the tank, supply lines, or injector hose. These heaters keep DEF from freezing or crystallizing in cold weather; when one underperforms the SCR system can stop dosing. Expect a warning light and, if ignored, a speed limit or no-restart derate.
What are the most common causes of P20C2?
The most common causes of P20C2 are: Failed DEF tank or supply-line heater element (heater C), Corroded or damaged connector at the DEF header/tank unit, Chafed, open, or shorted wiring in the heater control circuit, Failed heater relay or blown fuse feeding the heater circuit, Faulty DEF header assembly, Failed ECM/PCM heater driver. The specific cause varies by vehicle.
How much does it cost to fix P20C2?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P20C2?
Au7o has documented P20C2 across 1 vehicle models from 1 manufacturers: Jeep.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.