Description:

This diagnostic trouble code indicates that the on-time of the DEF dosing unit heater is faulty. This means the heater is not operating for the required duration to maintain the proper DEF temperature.

Reaction:

The ECU may limit or adjust the operation of the DEF dosing unit heater to manage the faulty on-time and ensure safe operation of the emissions control system.

Recommendations:

• Inspect DEF Dosing Unit Heater: Check for any signs of damage or wear on the DEF dosing unit heater. Replace if necessary.
• Check Electrical Supply: Ensure that the electrical supply to the DEF dosing unit heater is stable and within specifications.
• Test Heater Function: Use diagnostic tools to test the DEF dosing unit heater for proper operation and duration of heating cycles. Replace the heater if it is not functioning correctly.
• Verify Timer Settings: Ensure that the timer settings for the DEF dosing unit heater are correct and functioning as intended.
• Monitor Operating Conditions: Review the operating conditions that might contribute to faulty heater on-time, such as extreme cold weather.
• Reset ECU and Monitor System: After resolving the issue, reset the ECU to clear the fault code and monitor the system to ensure normal operation.

Note:

Ensuring the proper operation and on-time of the DEF dosing unit heater is essential for effective DEF dosing and emissions control. Regular inspections and timely maintenance can help prevent on-time related issues.