Fix P20AD: STEP-BY-STEP diagnostic GUIDE!

The P20AD: Reductant Metering Unit Temperature Sensor Circuit Range/Performance fault code indicates that the reductant metering unit temperature sensor is not operating within its expected range or performance parameters. This sensor monitors the temperature of the diesel exhaust fluid (DEF) to ensure accurate dosing. If the sensor is faulty or the circuit has issues, it can result in incorrect DEF dosing and emissions control problems. Common causes include incorrect sensor performance, a faulty temperature sensor, or sensor circuit problems.

P20AD – Quick Overview

CodeInformation
MeaningP20AD: Reductant Metering Unit Temperature Sensor Circuit Range/Performance
Is it serious?Yes, it can cause improper DEF dosing, leading to emissions control issues and potential system inefficiencies.
Possible causes– Incorrect sensor performance
– Faulty temperature sensor
– Sensor circuit problems
How to diagnose?– Test the sensor for range and performance
– Inspect wiring and connectors
– Check the sensor circuit

P20AD Meaning

The P20AD code signifies that the reductant metering unit temperature sensor is not functioning correctly within the expected performance range. This sensor is crucial for monitoring the temperature of the diesel exhaust fluid (DEF) to ensure it is injected correctly into the exhaust system. Incorrect sensor performance can result in improper DEF injection, affecting emissions control and overall engine performance.

Step-by-step diagnostic guide

ActionDescriptionTools Needed
Check for Other CodesUse an OBD-II scanner to check for additional related codes that may provide more information about the sensor circuit issue.OBD-II Scanner
Test the Sensor for Range/PerformanceUse a multimeter or diagnostic tool to test the temperature sensor and verify that it is operating within the specified range and performing accurately.Multimeter, Diagnostic Tool
Inspect Wiring and ConnectorsVisually inspect the wiring and connectors associated with the temperature sensor for any signs of damage, corrosion, or loose connections that could affect performance.Flashlight, Multimeter
Check the Sensor CircuitMeasure the voltage and resistance in the sensor circuit to ensure it is performing correctly and providing the necessary signals.Multimeter, Circuit Tester
Clear the Code and Test DriveAfter repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to ensure the issue has been resolved.OBD-II Scanner, Vehicle Owner’s Manual
Recheck for CodesAfter the test drive, re-scan the vehicle to ensure the P20AD code does not return. If it reappears, further diagnostics may be required.OBD-II Scanner
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