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P204FModerateEmissions

P204F: Reductant System Incorrect Quantity

1 vehicles · 1 makes · $300-$1,500 repair

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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 appears across 1 vehicle models from 1 manufacturers, with repair costs ranging from $300 to $1,500.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (1)
  • Related Codes
  • FAQ
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Common Causes

1Failed DEF injector
2Clogged DEF line
3Faulty DEF pump
4DEF quality sensor error
5Crystallized DEF in system

Typical Repair Cost

$300 - $1,500

Based on 1 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.

Budget Pick$10–$20

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
Check Price on Amazon
Best Value$90–$120

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)
Check Price on Amazon
Advanced$180–$230

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
Check Price on Amazon
Professional$350–$450

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
Check Price on Amazon

As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.

Vehicles Affected (1)

Silverado 3500HDCritical

DEF System Malfunction and Reduced Power

2011-2025$300-$1,500380 reports

Related Codes (8)

01447EVAP System (VAG)P0401Exhaust Gas Recirculation Flow InsufficientP0402Exhaust Gas Recirculation Flow ExcessiveP0403Exhaust Gas Recirculation Circuit MalfunctionP0404Exhaust Gas Recirculation Circuit Range/PerformanceP0410Secondary Air Injection System MalfunctionP0411Secondary Air Injection System Incorrect Flow DetectedP0412Secondary Air Injection System Switching Valve A Circuit

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 $1,500, depending on the vehicle and root cause.

Which vehicles are affected by P204F?

Au7o has documented P204F across 1 vehicle models from 1 manufacturers: Chevrolet.

Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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