John Deere 4766.18 – Engine Control Unit (ECU): DOC Outlet Temperature Moderately Low

The exhaust temperature exiting the Diesel Oxidation Catalyst (DOC) is not reaching the expected threshold during operation or regeneration, triggering a 'Cleaning system fault' and preventing active exhaust filter cleaning. If unaddressed, this results in engine power derating and 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
• 6190R
• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC
• 7210R
• 7230R
• 7250R
• 7270R
• 7290R
• 7310R
• 8245R to 8400R
• 8310RT
• 8335RT
• 8360RT
• 9470RT
• 9520RT
• 9570RT
• 210G
• 210GLC
• 85G
• 6105E
• 450K
• 550K

1. 1

   Check for engine software updates (e.g., SW63927D, SW61895G) that address DOC temperatures and reduce flow rate to assist with cleaning regens

2. 2

   Inspect the DOC Outlet Temperature Sensor (B5202) and its surroundings for contaminants that could affect temperature readings

3. 3

   Inspect wiring and connections between the DOC outlet temperature sensor, the Exhaust Filter Temperature Module (B5204), and the ECU for damage, fraying, or loose connectors. Test circuit for continuity and correct voltage

4. 4

   Inspect the fuel system and combustion efficiency for issues (insufficient fuel injection, improper combustion, incorrect air-fuel ratios) causing lower overall exhaust temperatures

5. 5

   Check the DOC for signs of inefficiency, face plugging, or blockages that might cause lower outlet temperatures

1. 1

   Verify Software

   Connect John Deere Service ADVISOR and verify if the ECU software is up to date. Flash the ECU with the latest payload if an update addressing DOC temperatures is available.

2. 2

   Cool Down

   Ensure the machine is turned off and allow the exhaust filter system to cool completely to prevent serious burns.

3. 3

   Disconnect Power

   Disconnect the battery negative (-) cable.

4. 4

   Remove the Sensor

   Locate the DOC outlet temperature sensor (B5202) on the exhaust filter assembly, disconnect the wire harness connector, and remove the sensor from the exhaust tube.

5. 5

   Install the New Sensor

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

6. 6

   Torque to Spec

   Thread the sensor into the exhaust housing and tighten it to a torque of 25 N·m to 34 N·m (18.5 to 25 lb-ft), depending on the specific engine's service manual.

7. 7

   Reconnect

   Reconnect the sensor wire harness and secure it with hold-down clamps and tie straps at the previous locations. Reconnect the battery negative cable.

8. 8

   Reset and Test

   Use Service ADVISOR to clear the 004766.18 fault code, reset the ECU, and perform a forced stationary exhaust filter cleaning (forced regen) to monitor the system and ensure the DOC outlet temperature reaches the normal operating range.