John Deere ECU003936.16 – ECU: Unexpected Temperature in Exhaust Filter

The Engine Control Unit (ECU) has detected a temperature differential between the Diesel Oxidation Catalyst (DOC) outlet and the Diesel Particulate Filter (DPF) outlet, indicating a moderately high level of unintended combustibles (unburnt fuel) in the DPF. When this fault is active, the active exhaust filter cleaning function becomes unavailable. Continued operation of the machine with this fault can lead to a loss of machine availability.

• 9470RT
• 9520RT
• 9570RT
• 8235R
• 8245R
• 8260R
• 8285R
• 8310R
• 8310RT
• 8335R
• 8335RT
• 8360R
• 8360RT
• 8400R
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC
• 4045
• Self-Propelled Forage Harvesters
• Sullair 300HH
• Sullair 375
• Sullair 375H
• Sullair 375HH
• Sullair 425
• Sullair 425H
• Vermeer D24x40 S3
• Vermeer D40x55 S3

1. 1

   Inspect the exhaust system for any leaks, especially between the turbocharger and the DPF.

2. 2

   Investigate the fuel system for issues that could cause unburnt fuel to enter the exhaust, such as leaking fuel injectors.

3. 3

   Visually inspect the exhaust temperature sensors and their wiring for any signs of damage, corrosion, or loose connections.

4. 4

   With a cold engine, use a diagnostic scanner to check live data from all exhaust temperature sensors. Readings should be close to ambient temperature; illogical readings indicate a faulty sensor.

5. 5

   Perform a resistance test on suspect temperature sensors by disconnecting them and measuring resistance with a multimeter while warming with a heat gun (resistance should change smoothly).

1. 1

   Address fuel system issues

   If a leaking injector or other fuel system fault is identified as the root cause of unburnt fuel entering the exhaust, repair or replace the faulty components.

2. 2

   Replace faulty sensors

   If a temperature sensor is identified as faulty through scanner or resistance testing, replace it.

3. 3

   Perform a parked regeneration

   After repairs, initiate a stationary or 'parked' regeneration of the DPF following the operator's manual to clear out any accumulated soot or unburnt fuel.

4. 4

   Clear fault codes

   Use a diagnostic scanner to clear the ECU 003936.16 fault code.

5. 5

   Verify repair

   Operate the machine under normal conditions to ensure the fault code does not reappear.