ECU 004376.05 – DEF Dosing Unit Reversing Valve, Resistance Too High. John Deere System Advisory.
ECU 004376.05 (ECU 4376.05)
Code: 004376.05
Shortcode: 4376.05
Description:
This diagnostic code is set when the ECU detects that the resistance in the DEF dosing unit reversing valve circuit is too high, typically indicating an open circuit. This can prevent the reversing valve from functioning properly, affecting the DEF dosing process.
Reaction:
The ECU may limit or adjust the operation of the DEF system to manage the high circuit resistance, potentially impacting DEF injection and overall emissions control efficiency.
Recommendations:
- Inspect Wiring and Connections: Check for damaged, frayed, or loose wiring and connectors in the DEF dosing unit reversing valve circuit. Repair or replace as necessary.
- Test Valve Element: Use diagnostic tools to test the reversing valve element for continuity and proper resistance. Replace the valve if it is faulty.
- Check for Corrosion: Inspect connections and components for signs of corrosion that could increase resistance. Clean or replace corroded parts.
- Verify Electrical Supply: Ensure that the electrical supply to the valve is stable and within specifications.
- 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 functioning of the DEF dosing unit reversing valve is crucial for effective DEF injection and maintaining the efficiency of the aftertreatment system. Regular inspections and timely maintenance can prevent valve-related issues.