Description:

This diagnostic trouble code indicates that the resistance in the Diesel Exhaust Fluid (DEF) dosing unit pump circuit is too low, typically indicating a short to ground. This condition can affect the proper functioning of the DEF dosing system.

Reaction:

The ECU may limit or adjust the operation of the DEF dosing unit to manage the low circuit resistance and ensure safe operation of the emissions control system.

Recommendations:

• Inspect Wiring and Connections: Check for damaged, frayed, or loose wiring and connectors associated with the DEF dosing unit pump. Repair or replace as necessary.
• Test DEF Pump Element: Use diagnostic tools to test the DEF dosing unit pump for proper resistance and continuity. Replace the pump if it is faulty.
• Check for Short Circuits: Inspect the circuit for any 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 DEF dosing unit pump 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:

Proper electrical function of the DEF dosing unit is crucial for accurate dosing and emissions control. Regular inspections and timely maintenance can help prevent resistance-related issues.