Description:

This code indicates that the resistance in the DEF dosing unit supply line heater circuit is too low. Low resistance typically indicates a short to ground, which can cause the heater to malfunction or fail.

Reaction:

The ECU may limit or adjust DEF system operation to prevent potential damage, impacting DEF injection and overall vehicle performance and emissions control.

Recommendations:

• Inspect Wiring and Connections: Check for damaged, frayed, or loose wiring and connectors in the DEF dosing unit supply line heater circuit. Repair or replace as necessary.
• Test Heater Element: Use diagnostic tools to test the heater element for proper resistance. Replace the heater if it is faulty.
• Check for Short Circuits: Inspect the circuit for points where wires may be touching ground, causing a short circuit. Repair or insulate as needed.
• Verify Electrical Supply: Ensure that the electrical supply to the heater is stable and within specifications.
• 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 electrical function of the DEF dosing unit supply line heater is essential for effective DEF injection, especially in cold conditions. Regular maintenance and timely repairs can help avoid resistance-related problems.