Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the system that helps reduce pollution from your car. It's like a broken switch in a toy that stops it from working.
The P20FA code indicates an issue with the electrical circuit that controls the reductant pump B, which is part of the vehicle's emission control system.
The reductant pump B is responsible for supplying diesel exhaust fluid (DEF) to the selective catalytic reduction (SCR) system. This system reduces harmful emissions. An open or malfunction in the control circuit can prevent the pump from operating correctly, leading to increased emissions.
• Check Engine Light is on
• Increased exhaust emissions
• Possible reduction in engine performance
• Faulty reductant pump B
• Open or shorted wiring in the control circuit
• Defective control module
Reductant: A substance used to reduce emissions, like diesel exhaust fluid.
SCR: Selective Catalytic Reduction, a system that reduces NOx emissions in diesel engines.
• Scan the vehicle for codes and freeze frame data.
• Inspect the wiring and connectors for damage or corrosion.
• Test the reductant pump B for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the reductant pump B if faulty.
• Update or replace the control module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $600
Moderate
• Ford F-250
• Chevrolet Silverado 2500
• Ram 2500
• Regular maintenance of the emission system
• Use high-quality diesel exhaust fluid
• Inspect wiring and connectors periodically
Emission Control Issue
• Address the issue promptly to avoid increased emissions.
• Consult a professional mechanic for accurate diagnosis.
Check vehicle's emission warranty; components may be covered.
This code has become more common with the increased use of SCR systems in diesel vehicles.
Moderate – Address soon to prevent potential damage to the emission system.
Ignoring emission-related codes can lead to failing emissions tests and potential fines.
• Engine running
• System warmed up to operating temperature
Typically located near the DEF tank or SCR catalyst.
Q: Can I drive with a P20FA code?
A: It's possible to drive, but it's recommended to fix the issue soon to avoid increased emissions.
Q: What happens if I ignore this code?
A: Ignoring this code can lead to higher emissions and potential damage to the emission control system.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.
Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.