John Deere 4766.17 – ECU: DOC Outlet Temperature Slightly Low

During an active exhaust filter cleaning (regeneration), the system expects the temperature exiting the Diesel Oxidation Catalyst (DOC) to reach a specific threshold to burn off soot. If the temperature is slightly lower than expected, the system cannot sustain the regeneration process, resulting in an 'Unable to continue cleaning' state. Continued operation with this active fault will result in a derate.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8235R
• 8260R
• 8285R
• 8310R
• 8310RT
• 8335R
• 8335RT
• 8360R
• 8360RT
• 9470RT
• 9520RT
• 9570RT
• 7R Series Tractors
• 7760 Cotton Pickers
• 210G
• 210GLC

1. 1

   Inspect the DOC Outlet Temperature Sensor for physical damage, heavy soot contamination, or a stuck reading, and compare the temperature reading to the DOC Inlet sensor before engine startup.

2. 2

   Inspect wiring and connections on the engine interface harness associated with the DOC outlet temperature sensor for damage, fraying, or looseness, and test the sensor circuit for continuity and correct voltage levels.

3. 3

   Check the EGR System (EGR Valve & Cooler) for heavy unburnt fuel (soot) deposits, which can cause poor EGR performance and low DOC outlet temperature.

4. 4

   Check the Hydrocarbon Doser (Fuel Dosing Valve) by monitoring the fuel line pressure to ensure the electronic dosing valve is not inoperative or clogged.

5. 5

   Inspect the exhaust piping before the DOC for any leaks that could allow heat to escape before reaching the sensor.

1. 1

   Cool Down

   Turn off the engine and allow the exhaust filter system to cool completely. CAUTION: The exhaust filter and surrounding components get extremely hot during operation and can cause serious burns.

2. 2

   Disconnect Power

   Disconnect the battery negative (—) cable.

3. 3

   Locate the Sensor

   Locate the DOC outlet temperature sensor on the Aftertreatment Device (ATD). It is typically threaded into the exhaust tube immediately after the Diesel Oxidation Catalyst and before the DPF.

4. 4

   Disconnect Wiring

   Remove any hold-down clamps or tie straps securing the sensor's wire harness. Tag and disconnect the wire harness connector from the sensor.

5. 5

   Remove Sensor

   Unscrew and remove the faulty DOC outlet temperature sensor from the exhaust housing.

6. 6

   Prepare New Sensor

   Apply appropriate high-temperature anti-seize compound (Tooling A) to the threads of the new DOC outlet temperature sensor.

7. 7

   Install Sensor

   Thread the new sensor into the housing and tighten it to the specified torque (OEM spec for this sensor is generally 25 N·m to 34 N·m, depending on the exact engine model).

8. 8

   Reconnect Wiring

   Reconnect the wire harness connector and secure the leads with tie straps at their previous locations to prevent chafing.

9. 9

   Restore Power

   Reconnect the battery negative (—) cable.

10. 10

    Clear and Test

    Reset the ECU to clear the 004766.17 fault code. Initiate a parked/stationary exhaust filter cleaning (regeneration) via the CommandCenter™ to monitor the system and verify that the DOC outlet temperature reaches the required threshold.