P204F: Reductant System Incorrect Quantity
3 vehicles · 3 makes · $300-$4,500 repair
Most Reported On
P204F is an OBD-II diagnostic trouble code meaning “Reductant System Incorrect Quantity.” The DEF (diesel exhaust fluid) injection quantity is incorrect. Part of the SCR emissions system on diesel vehicles. This code is most commonly reported on 2015-2022 Ford F-250 Super Duty, 2011-2025 Chevrolet Silverado 3500HD, and 2018-2024 Dacia Duster (Essential, Comfort, Prestige, Extreme), with repair costs ranging from $300 to $4,500.
Common Causes
Typical Repair Cost
Based on 3 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P204F, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all 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 diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (3)
FAQ
What does P204F mean?
P204F stands for "Reductant System Incorrect Quantity." The DEF (diesel exhaust fluid) injection quantity is incorrect. Part of the SCR emissions system on diesel vehicles.
What are the most common causes of P204F?
The most common causes of P204F are: Failed DEF injector, Clogged DEF line, Faulty DEF pump, DEF quality sensor error, Crystallized DEF in system. The specific cause varies by vehicle.
How much does it cost to fix P204F?
Repair costs for P204F range from $300 to $4,500, depending on the vehicle and root cause.
Which vehicles are affected by P204F?
Au7o has documented P204F across 3 vehicle models from 3 manufacturers: Chevrolet, Dacia, Ford.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.