Engine-CodesGeneric – P20AC

P20AC Code - Reductant Metering Unit Temperature Sensor Circuit

Quick Answer

The P20AC code indicates a problem with the reductant metering unit temperature sensor circuit. Common causes include Faulty Temperature Sensor: The most common cause of this code is a malfunctioning temperature sensor in the reductant metering unit, Wiring Issues: Problems with the wiring connections or harnesses related to the temperature sensor can also trigger this code, Corrosion or Contamination: Corrosion or contamination in the sensor or its connections can lead to inaccurate readings. 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
P20AC indicates Reductant Metering Unit Temperature Sensor Circuit.
Common causes
Common causes include Faulty Temperature Sensor: The most common cause of this code is a malfunctioning temperature sensor in the reductant metering unit, Wiring Issues: Problems with the wiring connections or harnesses related to the temperature sensor can also trigger this code, Corrosion or Contamination: Corrosion or contamination in the sensor or its connections can lead to inaccurate readings.
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
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P20AC Description

The P20AC code indicates a problem with the reductant metering unit temperature sensor circuit. The reductant metering unit is a crucial component of the vehicle's selective catalytic reduction (SCR) system, which is responsible for reducing harmful emissions. The temperature sensor in the unit is designed to monitor the temperature of the reductant fluid to ensure it is at the optimal temperature for the SCR system to function efficiently.

OBDII Code P20AC - Reductant Metering Unit Temperature Sensor Circuit
P20AC Code - Reductant Metering Unit Temperature Sensor Circuit

Common Causes of P20AC

  1. Faulty Temperature Sensor: The most common cause of this code is a malfunctioning temperature sensor in the reductant metering unit.
  2. Wiring Issues: Problems with the wiring connections or harnesses related to the temperature sensor can also trigger this code.
  3. Corrosion or Contamination: Corrosion or contamination in the sensor or its connections can lead to inaccurate readings.
  4. Software or Calibration Issues: Issues with the software or calibration of the SCR system can also cause this code to appear.

Symptoms of P20AC

  1. Check Engine Light: The most common symptom of this code is the illumination of the check engine light on the vehicle's dashboard.
  2. Reduced Fuel Efficiency: A faulty temperature sensor can lead to poor fuel efficiency as the SCR system may not be operating at its optimal level.
  3. Decreased Engine Performance: The vehicle may experience a decrease in engine performance due to the inefficient operation of the SCR system.
  4. Increased Emissions: The vehicle may produce higher emissions than usual if the reductant fluid temperature is not regulated properly.

How to Fix P20AC

  1. Diagnose the Issue: The first step in repairing this code is to diagnose the specific cause of the problem, which may involve testing the temperature sensor, checking the wiring, and inspecting for any corrosion or contamination.
  2. Replace the Temperature Sensor: If the sensor is found to be faulty, it will need to be replaced with a new one to restore proper operation of the SCR system.
  3. Repair Wiring Connections: If the issue is related to wiring problems, repairing or replacing the damaged connections can resolve the code.
  4. Clear the Code: Once the repair is completed, the code should be cleared from the vehicle's onboard computer to reset the system and ensure the issue has been resolved.

Cost to Fix P20AC

The cost of repairing the P20AC code can vary depending on the specific cause of the issue and the make and model of the vehicle. In general, the cost of replacing a temperature sensor can range from $100 to $300, including parts and labor. Additional costs may be incurred if wiring repairs or other components need to be replaced. It's important to consult with a professional mechanic to get an accurate estimate for your specific situation. Labor rates at auto repair shops can vary, so it's advisable to check local rates for a more precise estimate.

Need more information about the P20AC code?

Need more information on how to fix the P20AC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P20AC code diagnosed by a professional: Find a repair shop in your area

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.

Frequently Asked Questions about P20AC Code

No Frequently Asked Questions about P20AC Code found.

Discuss the causes and fixes for P20AC OBDII Code

Code P20AC comments

No comments found for this page.