Resetting a DEF level sensor typically requires a professional diesel diagnostic tool, as basic OBD2 scanners cannot complete this operation. Below are the general and vehicle-specific steps:
I. General Reset Procedure
Preparation: Park the vehicle securely and turn the ignition to the "ON" position (without starting the engine). Connect a diesel diagnostic adapter compatible with the specific vehicle model (e.g., Nexiq USB-Link series) and launch the corresponding diagnostic software.
System Test: Perform a DEF injection test via the diagnostic interface to verify that parameters such as pump pressure and injection status are normal; otherwise, the subsequent reset will not take effect.
Step-by-Step Reset: Sequentially perform the NOx sensor reset and SCR efficiency reset. Finally, select the "DEF System Reset" option to clear historical data regarding fluid levels and pressure.
Verification: Wait for the reset process to complete, then start the engine and confirm that the DEF warning light on the dashboard has turned off.
II. Model-Specific Procedures
Volvo Models (US17+ Emission Standards)
Ensure the DEF tank is not frozen and the fluid level is sufficient. After clearing fault codes, run the engine at a high idle (above 1000 rpm) for 2 minutes, turn off the ignition for 15 seconds, and then repeat the high-idle run for another 2 minutes to complete the reset verification.
Paccar MX-13 Models
In the diagnostic software, navigate to the Aftertreatment System > DEF Tank Level Sensor menu. Select the "Relearn/Calibrate" option. Ensure the tank is at least 3/4 full and there are no active fault codes. Wait 2–5 minutes for calibration to complete, then cycle the power (turn off and restart) to finalize the process.
If the fault light remains on after the reset, inspect the sensor itself and the associated wiring for hardware damage.
Resetting a DEF level sensor typically requires a professional diesel diagnostic tool, as basic OBD2 scanners cannot complete this operation. Below are the general and vehicle-specific steps:
I. General Reset Procedure
Preparation: Park the vehicle securely and turn the ignition to the "ON" position (without starting the engine). Connect a diesel diagnostic adapter compatible with the specific vehicle model (e.g., Nexiq USB-Link series) and launch the corresponding diagnostic software.
System Test: Perform a DEF injection test via the diagnostic interface to verify that parameters such as pump pressure and injection status are normal; otherwise, the subsequent reset will not take effect.
Step-by-Step Reset: Sequentially perform the NOx sensor reset and SCR efficiency reset. Finally, select the "DEF System Reset" option to clear historical data regarding fluid levels and pressure.
Verification: Wait for the reset process to complete, then start the engine and confirm that the DEF warning light on the dashboard has turned off.
II. Model-Specific Procedures
Volvo Models (US17+ Emission Standards)
Ensure the DEF tank is not frozen and the fluid level is sufficient. After clearing fault codes, run the engine at a high idle (above 1000 rpm) for 2 minutes, turn off the ignition for 15 seconds, and then repeat the high-idle run for another 2 minutes to complete the reset verification.
Paccar MX-13 Models
In the diagnostic software, navigate to the Aftertreatment System > DEF Tank Level Sensor menu. Select the "Relearn/Calibrate" option. Ensure the tank is at least 3/4 full and there are no active fault codes. Wait 2–5 minutes for calibration to complete, then cycle the power (turn off and restart) to finalize the process.
If the fault light remains on after the reset, inspect the sensor itself and the associated wiring for hardware damage.
