P20E9 on 2014-2016 Jeep Grand Cherokee — Reductant Pressure Too High
1 vehicles · 1 makes
Most Reported On
P20E9 is an OBD-II diagnostic trouble code meaning “Reductant Pressure Too High.” A generic emissions code for diesel vehicles with an SCR aftertreatment system. The reductant (DEF/AdBlue) pressure sensor reports delivery pressure above the manufacturer's specified range, which normally means the fluid cannot flow out of the system properly — most often a restriction downstream of the pump. Expect a check engine light, DEF system warnings, and reduced power or a derate, since manufacturers treat DEF faults as emissions-inducement conditions. This code is most commonly reported on 2014-2016 Jeep Grand Cherokee.
Common Causes
Diagnostic Tools
This is a powertrain code, so a basic OBD-II reader can read it. These read P20E9.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.
- Read & clear engine (P) codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X V3.0 Elite OBD-II Scanner
by LAUNCH
Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
What you can do yourself, and what needs a shop
Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:
- Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
- Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
- Airbag/SRS component work — a stored fault can deploy a live device.
If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.
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FAQ
What does P20E9 mean?
P20E9 stands for "Reductant Pressure Too High." A generic emissions code for diesel vehicles with an SCR aftertreatment system. The reductant (DEF/AdBlue) pressure sensor reports delivery pressure above the manufacturer's specified range, which normally means the fluid cannot flow out of the system properly — most often a restriction downstream of the pump. Expect a check engine light, DEF system warnings, and reduced power or a derate, since manufacturers treat DEF faults as emissions-inducement conditions.
What are the most common causes of P20E9?
The most common causes of P20E9 are: Crystallized DEF blocking the injector or the reductant line (most common), Clogged, kinked, or frozen DEF supply line, Failed or stuck DEF/reductant injector (dosing valve), Faulty reductant pressure sensor reporting false high pressure, DEF pump module fault causing over-pressurization, including a failed pressure-relief or reverting valve, Contaminated or poor-quality DEF causing deposits throughout the system. The specific cause varies by vehicle.
How much does it cost to fix P20E9?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P20E9?
Au7o has documented P20E9 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.