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 heater in the tank that holds a special fluid for your car's emissions system is not working properly because the electrical signal is too high.
The P202C code is triggered when the engine control module (ECM) detects a high voltage condition in the reductant tank heater control circuit.
The reductant tank heater is used to prevent the diesel exhaust fluid (DEF) from freezing in cold temperatures. The ECM monitors the heater's control circuit for proper operation. If the voltage is higher than expected, the ECM sets the P202C code.
• Check Engine Light illuminated
• Possible reduction in engine performance
• Emissions system warnings
• Faulty reductant tank heater
• Open or shorted wiring in the heater circuit
• Faulty ECM
ECM: Engine Control Module
DEF: Diesel Exhaust Fluid
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the reductant tank heater for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the reductant tank heater if faulty.
• Replace or reprogram 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 components.
• Ensure proper maintenance of electrical connections.
• Use high-quality DEF fluid.
Sensor Issue
• Address the issue promptly to avoid emissions problems.
• Consult a professional mechanic if unsure about repairs.
Check with your vehicle manufacturer for specific warranty coverage on emissions-related components.
This code has become more common with the increased use of DEF systems in diesel vehicles.
Moderate – While not immediately critical, it should be addressed to maintain emissions compliance and vehicle performance.
Operating a vehicle with emissions system faults may violate emissions regulations and can lead to fines.
• Engine at operating temperature
• Cold ambient temperatures where DEF freezing is possible
The reductant tank heater is located within or near the DEF tank, typically at the rear of the vehicle.
Q: What is a reductant tank heater?
A: It's a device that keeps the DEF fluid from freezing in cold weather.
Q: Can I drive with a P202C code?
A: It's not recommended to drive for extended periods with this code as it may affect emissions and performance.
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