John Deere 4766.12 – Engine Control Unit (ECU): DOC Outlet Temperature Sensor Issue / DOC Outlet Temperature Error

The exhaust filter temperature module has detected a problem with measuring the temperature at the outlet of the Diesel Oxidation Catalyst (DOC). Accurate measurement here is critical for assessing the performance and efficiency of the exhaust aftertreatment system. Symptoms include the ECU disabling active exhaust filter cleaning (regeneration), leading to engine power deration or a complete loss of machine availability.

• 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
• 5045E
• 6M Series
• 6R Series
• 7R Series
• 8310RT
• 8335RT
• 8360RT
• 210G
• 210GLC
• 624K
• 724K
• 744K
• 824K
• E-Series articulated dump trucks
• D24x40 S3
• D40x55 S3

1. 1

   Visually check the DOC outlet temperature sensor for physical damage, heavy soot buildup, or melting

2. 2

   Inspect wiring and connections for damaged, frayed, or loose wiring associated with the DOC outlet temperature sensor circuit

3. 3

   Ensure that the sensor and its surroundings are free from contaminants that could skew temperature readings

4. 4

   Test the sensor circuit for continuity using a multimeter or John Deere diagnostic tool, and verify it is receiving the correct reference voltage from the ECU

1. 1

   Safety First

   Turn off the machine and disconnect the battery negative (-) cable.

2. 2

   Cool Down

   WARNING: Allow the exhaust filter and surrounding components to cool completely before servicing. The exhaust filter operates at extremely high temperatures and can cause serious burns.

3. 3

   Locate the Sensor

   Locate the DOC Outlet Temperature Sensor on the exhaust aftertreatment system (typically threaded into the exhaust tubing just after the DOC and before the DPF).

4. 4

   Disconnect

   Unplug the wire harness connector from the sensor.

5. 5

   Remove

   Carefully unscrew and remove the faulty sensor from the exhaust housing.

6. 6

   Prep the New Sensor

   Apply a high-temperature anti-seize compound to the threads of the new sensor (if not already pre-applied by the manufacturer).

7. 7

   Install

   Thread the new DOC outlet temperature sensor into place. Tighten to the specified torque (OEM manuals generally specify between 25 N·m to 34 N·m depending on the exact engine model).

8. 8

   Reconnect

   Reconnect the wire harness connector and secure any tie straps or hold-down clamps.

9. 9

   Restore Power

   Reconnect the battery negative cable.

10. 10

    Clear Codes

    Reset the ECU to clear the fault code. Start the engine and monitor the system to ensure accurate temperature measurement and verify that there are no exhaust leaks.