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 part of the car that heats up a special liquid used to clean the exhaust. It's like when a heater in your house stops working.
The P20C1 code indicates an issue with the control circuit for the third heater in the diesel exhaust fluid (DEF) system, which is responsible for heating the reductant to ensure proper operation.
The reductant heater is part of the Selective Catalytic Reduction (SCR) system in diesel engines. It heats the DEF to prevent it from freezing and to ensure it can be injected properly into the exhaust stream. An open circuit or failure in the control circuit for Heater C can prevent the DEF from being heated, leading to potential SCR system inefficiencies.
• Check Engine Light is on
• Poor engine performance
• Increased emissions
• Faulty reductant heater C
• Damaged wiring or connectors
• Faulty control module
OBD-II: On-Board Diagnostics, a standardized system for vehicle self-diagnosis and reporting.
DEF: Diesel Exhaust Fluid, a liquid used in diesel engines to reduce emissions.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the reductant heater C for continuity.
• Replace the faulty reductant heater C.
• Repair or replace damaged wiring or connectors.
• Replace the control module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$200 - $500
Moderate
• Ford F-250
• Chevrolet Silverado 2500
• Ram 2500
• Regularly inspect wiring and connectors for damage.
• Ensure DEF system maintenance is performed as scheduled.
• Use quality DEF fluid to prevent contamination.
Sensor Issue
• Have the vehicle inspected by a professional mechanic.
• Avoid ignoring the Check Engine Light, as it can lead to bigger issues.
• Regular maintenance can prevent such issues.
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 engines to meet emissions standards.
Moderate – It's important to address this issue to maintain emissions compliance and vehicle performance.
Ignoring emissions-related repairs can lead to fines and increased pollution.
• Vehicle must be running.
• DEF system must be active.
The reductant heater is typically located near the DEF tank or within the DEF delivery system.
Q: Can I drive with a P20C1 code?
A: It's not recommended to drive for extended periods with this code, as it can lead to increased emissions and potential engine performance issues.
Q: How often should the DEF system be checked?
A: The DEF system should be checked during regular maintenance intervals, as specified in your vehicle's owner manual.
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