Engine-CodesGeneric – P20C0

P20C0 Code - Reductant Heater 2 Control Circuit High Voltage

Quick Answer

The P20C0 diagnostic trouble code (DTC) indicates an issue with the reductant heater 2 control circuit in a vehicle's emissions system. Common causes include Faulty Reductant Heater: The issue may stem from a malfunctioning reductant heater, which can cause the control circuit to register high voltage, Wiring Issues: Damaged or corroded wiring in the reductant heater 2 control circuit can also trigger the P20C0 code, Faulty Sensor: A defective sensor that monitors the voltage in the reductant heater circuit can lead to this code being triggered. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P20C0 indicates Reductant Heater 2 Control Circuit High Voltage.
Common causes
Common causes include Faulty Reductant Heater: The issue may stem from a malfunctioning reductant heater, which can cause the control circuit to register high voltage, Wiring Issues: Damaged or corroded wiring in the reductant heater 2 control circuit can also trigger the P20C0 code, Faulty Sensor: A defective sensor that monitors the voltage in the reductant heater circuit can lead to this code being triggered.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Table of contents Created and updated by William Orellana on Sep 10, 2024
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Code P20C0 Description

The P20C0 diagnostic trouble code (DTC) indicates an issue with the reductant heater 2 control circuit in a vehicle's emissions system. The reductant heater is responsible for heating the diesel exhaust fluid (DEF) before it enters the selective catalytic reduction (SCR) system to reduce harmful emissions. In this case, the control circuit is detecting a high voltage, which can disrupt the proper functioning of the reductant heater.

OBDII Code P20C0 - Reductant Heater 2 Control Circuit High Voltage
P20C0 Code - Reductant Heater 2 Control Circuit High Voltage

Common Causes of P20C0

  1. Faulty Reductant Heater: The issue may stem from a malfunctioning reductant heater, which can cause the control circuit to register high voltage.
  2. Wiring Issues: Damaged or corroded wiring in the reductant heater 2 control circuit can also trigger the P20C0 code.
  3. Faulty Sensor: A defective sensor that monitors the voltage in the reductant heater circuit can lead to this code being triggered.
  4. Software/Programming Error: An issue with the vehicle's onboard computer software or programming may cause the control circuit to detect high voltage erroneously.

Symptoms of P20C0

  1. Check Engine Light: The most common symptom associated with the P20C0 code is the illumination of the check engine light on the vehicle's dashboard.
  2. Reduced Fuel Efficiency: A malfunctioning reductant heater can lead to decreased fuel efficiency as the emissions system may not be operating optimally.
  3. Failed Emissions Test: If the reductant heater is not functioning correctly, the vehicle may fail emissions tests due to increased pollution output.
  4. Rough Idling: In some cases, a malfunctioning reductant heater can cause the vehicle to idle roughly or experience fluctuations in engine performance.

How to Fix P20C0

  1. Diagnose the Issue: Begin by using a diagnostic scanner to retrieve the DTC and pinpoint the specific cause of the high voltage in the reductant heater 2 control circuit.
  2. Inspect Wiring and Connections: Check the wiring and connections in the reductant heater circuit for any damage, corrosion, or loose connections. Repair or replace any faulty components as needed.
  3. Test Reductant Heater: Test the reductant heater to ensure it is functioning correctly. Replace the heater if it is found to be faulty.
  4. Check Sensor: Inspect the sensor responsible for monitoring the voltage in the circuit. Replace the sensor if it is malfunctioning.
  5. Clear Codes and Test Drive: After making the necessary repairs, clear the DTC from the vehicle's computer and test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P20C0

The cost of repairing a P20C0 code can vary depending on the specific cause of the issue and the make and model of the vehicle. In general, the parts needed for this repair, such as a new reductant heater or sensor, can range from $100 to $500. Labor costs typically add an additional $100 to $300, bringing the total repair cost to between $200 and $800.

Tech Notes for P20C0

























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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

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