John Deere ECU003720.15 – ECU: High Ash Load in Exhaust Filter

The ash content in the exhaust gas filter (DPF) has reached a high level, necessitating professional filter maintenance. Ash is a noncombustible residue from engine oil and fuel additives that accumulates over time, reducing the filter's capacity to store soot and increasing exhaust system back pressure. When this code is triggered, automatic or parked filter cleanings are no longer sufficient to resolve the issue, which may reduce filter efficiency and negatively affect engine performance.

• 210K
• 310K
• 310SK
• 310TK
• 410K
• 410TK
• 5085E
• 5085M
• 5100E
• 5100M
• 5100MH
• 5100ML
• 5115M
• 5115ML
• 4045HFC92
• 4045HFG92

1. 1

   Verify that ECU 003720.15 is an active fault code.

2. 2

   Attempt a parked regeneration to ensure all operator-level cleaning procedures have been tried. If it fails or the light returns shortly after, professional service is confirmed.

3. 3

   Inspect the intake and exhaust systems for any leaks, loose connections, or missing plugs that could affect sensor readings.

4. 4

   Ensure that the NOx sensors and other related aftertreatment sensors and modules have secure electrical connections with good power and ground.

5. 5

   Using a diagnostic tool, monitor the upstream and downstream DPF temperature sensors. A significant temperature increase during a forced regeneration attempt indicates proper combustion.

1. 1

   Remove DPF

   Remove the Diesel Particulate Filter (DPF) assembly from the machine. This is not an operator-level task and must be performed by a qualified service provider.

2. 2

   Clean or replace DPF

   Clean the removed DPF using specialized equipment designed to extract hardened ash (do not use water or chemicals, as they can damage the filter), or exchange it for a new or remanufactured unit.

3. 3

   Reinstall DPF

   Install the cleaned or replacement DPF back onto the machine.

4. 4

   Reset ECU ash level

   Use a dealer-level diagnostic tool, such as John Deere Service Advisor, to reset the ash level calculation within the ECU. This crucial step informs the engine control module that a clean filter has been installed.