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 a part of the car that helps keep a special fluid warm. This fluid helps the car clean its exhaust before it goes into the air. If the fluid isn't warm enough, it can't do its job properly.
The P20BD code indicates an issue with the electrical circuit that controls the heater for the reductant, which is used in diesel exhaust fluid systems to reduce emissions.
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 the correct temperature to prevent freezing and to allow proper dosing into the exhaust stream. An open circuit or control issue in Heater B can lead to improper DEF dosing, affecting emissions control.
• Check Engine Light is on
• Vehicle may not meet emissions standards
• Potential reduction in engine performance
• Faulty reductant heater
• Open or shorted wiring in the heater circuit
• Faulty control module
Reductant: A substance used in diesel engines to reduce emissions.
SCR: Selective Catalytic Reduction, a system to reduce nitrogen oxide emissions in diesel engines.
• Use a scan tool to verify the code and check for any other related codes.
• Inspect the wiring and connectors for the reductant heater for damage or corrosion.
• Test the reductant heater for proper operation using a multimeter.
• Repair or replace damaged wiring or connectors.
• Replace the reductant heater if it is faulty.
• Replace or reprogram the control module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$200 - $500
Moderate
• Ford F-Series
• Chevrolet Silverado
• Ram 2500
• Regularly inspect and maintain wiring and connectors.
• Ensure the DEF system is serviced as per manufacturer recommendations.
• Use high-quality DEF fluid.
Sensor Issue
• Have your vehicle inspected by a professional if the Check Engine Light comes on.
• Avoid ignoring the issue as it can lead to increased emissions.
• Consider regular maintenance checks to prevent such issues.
Check with your vehicle manufacturer as emissions-related components may have extended warranties.
The P20BD code has been more common in diesel vehicles equipped with SCR systems since stricter emissions standards were implemented.
Moderate – While the vehicle may still be drivable, emissions control is compromised.
Driving with this code may not comply with emissions regulations, which can lead to fines or failed inspections.
• Engine at operating temperature
• DEF system active
The reductant heater is typically located near the DEF tank or within the DEF injector assembly.
Q: Can I drive with a P20BD code?
A: While you can drive with this code, it is not recommended as it affects emissions control.
Q: How do I clear a P20BD code?
A: The code can be cleared using an OBD-II scanner after repairs are made, but it may return if the issue is not resolved.
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