Description:

This diagnostic trouble code indicates that the DEF tank heater coolant control valve is stuck open, leading to a DEF tank temperature that is higher than expected. This can affect the proper heating and operation of the DEF system, potentially causing performance issues.

Reaction:

The ECU may limit or adjust the operation of the DEF system to manage the high DEF tank temperature, potentially impacting DEF injection and overall emissions control efficiency.

Recommendations:

• Inspect Control Valve: Check the DEF tank heater coolant control valve for any mechanical issues that might cause it to remain open. Clean or replace the valve if necessary.
• Inspect Wiring and Connections: Check for damaged, frayed, or loose wiring and connectors in the coolant valve circuit. Repair or replace as necessary.
• Test Valve Operation: Use diagnostic tools to test the operation of the coolant control valve. Ensure it can open and close as required.
• Check for Obstructions: Inspect the valve and associated components for any obstructions that might prevent the valve from closing.
• Reset ECU and Monitor System: After addressing the issue, reset the ECU to clear the fault code and monitor the system to ensure the valve operates correctly.

Note:

Proper operation of the DEF tank heater coolant control valve is crucial for maintaining the correct DEF tank temperature and ensuring effective DEF injection. Regular maintenance can help prevent valve-related issues.