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 keeps a special liquid in your car from freezing. This liquid helps clean the car's exhaust to make it less polluting.
The P20BA code is triggered when the engine control module (ECM) detects an issue with the performance of the control circuit for the reductant heater A. This heater is part of the diesel exhaust fluid (DEF) system, which prevents the fluid from freezing.
The reductant heater is part of the Selective Catalytic Reduction (SCR) system in diesel engines. It ensures that the DEF, which is a mixture of urea and deionized water, remains in a liquid state. The ECM monitors the heater's circuit for proper operation. If the circuit performance is outside the expected range, the P20BA code is set.
• Check Engine Light illuminated
• Poor engine performance
• Increased emissions
• Faulty reductant heater
• Open or shorted wiring in the heater circuit
• Faulty ECM or control module
Reductant: A substance used in the SCR system to reduce emissions.
DEF: Diesel Exhaust Fluid, a mixture of urea and deionized water.
• Use an OBD-II scanner to confirm the code.
• Inspect the reductant heater and related wiring for damage.
• Test the heater's resistance and continuity.
• Replace the faulty reductant heater.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-250
• Chevrolet Silverado
• Ram 2500
• Regularly inspect the DEF system.
• Use high-quality DEF fluid.
• Ensure proper maintenance of the vehicle's electrical system.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if you are unsure.
• Ensure the DEF system is in good condition, especially in cold climates.
Check with your vehicle manufacturer for warranty coverage on emissions-related components.
This code has become more common with the increased use of SCR systems in diesel vehicles to meet stringent emissions standards.
Moderate – It is important to address this issue to maintain vehicle performance and emissions compliance.
Driving with this code may result in increased emissions, which can be illegal in some areas.
• Engine at operating temperature
• DEF system active
The reductant heater is located within the DEF tank or along the DEF lines in the vehicle's exhaust system.
Q: Can I drive with a P20BA code?
A: It's possible to drive short distances, but it's best to fix the issue soon to avoid increased emissions and potential engine performance problems.
Q: How do I reset the P20BA code?
A: After repairs, the code can be reset using an OBD-II scanner. If the problem persists, the code will return.
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