Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car is using too much of a special fluid called reductant, which helps clean the car's exhaust. It's like if you were drinking too much water too quickly.
The P20F5 code is triggered when the engine control module (ECM) detects that the vehicle is using more reductant fluid than expected to reduce emissions.
The reductant, commonly known as Diesel Exhaust Fluid (DEF), is injected into the exhaust system to reduce nitrogen oxide emissions. This code indicates that the consumption rate of the DEF is higher than the parameters set by the manufacturer, suggesting a possible leak, malfunction in the dosing system, or incorrect fluid concentration.
• Check Engine Light is on
• Increased DEF consumption
• Possible reduction in engine performance
• Leaking reductant tank or lines
• Faulty reductant injector
• Incorrect reductant fluid concentration
Reductant: A fluid used in diesel engines to reduce emissions.
DEF: Diesel Exhaust Fluid, a type of reductant.
• Check for leaks in the reductant tank and lines.
• Inspect the reductant injector for proper operation.
• Verify the concentration and quality of the reductant fluid.
• Repair or replace leaking components.
• Replace faulty reductant injector.
• Drain and refill with correct reductant fluid.
• OBD-II scanner
• Wrench set
• DEF refractometer
$200 - $600
Moderate
• Ford F-250
• Chevrolet Silverado 2500
• Ram 2500
• Regularly check DEF levels and quality.
• Inspect for leaks periodically.
• Use manufacturer-recommended DEF.
Emission Control System
• Monitor DEF usage regularly.
• Address Check Engine Light promptly to avoid further issues.
Emission-related components may have extended warranty coverage. Check with the manufacturer.
This code has become more common with the increased use of DEF systems in diesel engines to meet stricter emission standards.
Moderate – While the vehicle may still operate, excessive DEF consumption can lead to increased maintenance costs and potential emission test failures.
Ignoring emission-related codes can result in fines and failing vehicle inspections in some regions.
• Engine at operating temperature
• Vehicle driven under normal conditions
The reductant tank is typically located near the rear of the vehicle, and the injector is in the exhaust system.
Q: Can I drive with a P20F5 code?
A: You can drive, but it's best to address the issue soon to avoid increased maintenance costs.
Q: How often should I refill DEF?
A: DEF consumption varies, but it typically needs refilling every 3,000 to 5,000 miles.
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