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's computer is having trouble controlling a special system that helps reduce pollution. It's like when a toy's remote control isn't working right.
The P20FF code indicates a performance issue with the reductant control module, which manages the diesel exhaust fluid system to reduce emissions.
The reductant control module is responsible for the operation of the selective catalytic reduction (SCR) system in diesel engines. It controls the injection of diesel exhaust fluid (DEF) into the exhaust stream to reduce nitrogen oxide emissions. A P20FF code is set when the module does not perform as expected, potentially due to software or hardware malfunctions.
• Check Engine Light is on
• Reduced engine performance
• Increased emissions
• Faulty reductant control module
• Wiring issues or poor connections
• Software glitches in the control module
Reductant: A substance used to reduce pollution in exhaust gases.
SCR: Selective Catalytic Reduction, a system to reduce emissions in diesel engines.
• Use an OBD-II scanner to confirm the code.
• Inspect wiring and connections related to the reductant control module.
• Test the reductant control module for proper operation.
• Repair or replace faulty wiring or connectors.
• Reprogram or update the reductant control module software.
• Replace the reductant control module if necessary.
• OBD-II scanner
• Multimeter
• Diagnostic software tool
$200 - $800
Moderate
• Ford F-250
• Chevrolet Silverado 2500
• Ram 2500
• Regularly check and maintain DEF levels.
• Perform routine inspections of the SCR system.
• Keep vehicle software up to date.
Emission Control System Issue
• Avoid driving long distances until the issue is resolved.
• Consult a professional mechanic for diagnosis and repair.
Check with the vehicle manufacturer for warranty coverage on emission control components.
This code has become more common with the increased use of SCR systems in diesel engines to meet stricter emission standards.
Moderate – It should be addressed soon to prevent increased emissions and potential engine performance issues.
Operating a vehicle with this issue may result in failing emissions tests and could be against environmental regulations.
• Engine running
• Vehicle at operating temperature
The reductant control module is typically located near the DEF tank or SCR system, often under the vehicle.
Q: Can I drive with a P20FF code?
A: While the vehicle may still be drivable, it's best to address the issue soon to avoid increased emissions and potential engine problems.
Q: What is diesel exhaust fluid?
A: Diesel exhaust fluid (DEF) is a liquid used in diesel engines to reduce nitrogen oxide emissions.
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