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 heater that helps keep a special fluid warm in your car. It's like when your electric blanket doesn't work because the plug is loose.
The P20BF code indicates that the control circuit for the second reductant heater is experiencing low voltage, which means it might not be working properly.
The reductant heater is part of the Selective Catalytic Reduction (SCR) system in diesel engines. It ensures that the Diesel Exhaust Fluid (DEF) remains at an optimal temperature. A low control circuit signal suggests a potential issue with the heater's electrical circuit, possibly due to wiring, connections, or the heater itself.
• Check Engine Light is on
• Poor engine performance
• Increased emissions
• Faulty reductant heater B
• Damaged wiring or connectors
• Faulty control module
Reductant: A fluid used in the SCR system to reduce emissions.
SCR: Selective Catalytic Reduction, a system that reduces emissions in diesel engines.
• Use an OBD-II scanner to confirm the code
• Inspect the wiring and connectors for damage
• Test the reductant heater B for proper operation
• Repair or replace damaged wiring or connectors
• Replace the reductant heater B if faulty
• Update or reprogram the control module if necessary
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-250
• Chevrolet Silverado 2500
• Ram 2500
• Regularly inspect and maintain the DEF system
• Ensure connectors are secure and free of corrosion
• Use high-quality DEF fluid
Sensor Issue
• Avoid driving long distances until repaired
• Regularly check for any leaks or damage
• Consult a professional mechanic if unsure
Check vehicle's emissions warranty; components related to emissions may be covered.
This code has become more common with the increased use of SCR systems in diesel vehicles.
Moderate – Should be addressed soon to avoid potential engine performance issues.
Ignoring emissions-related issues can lead to legal penalties and increased pollution.
• Engine at operating temperature
• Vehicle in a safe, stationary position
The reductant heater is typically located near the DEF tank or in the DEF line.
Q: Can I drive with a P20BF code?
A: It's not recommended to drive long distances as it may affect engine performance and emissions.
Q: What happens if I ignore this code?
A: Ignoring it can lead to increased emissions, poor engine performance, and potential legal issues.
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