New Holland ENG 1804 – Engine Control Unit (ECU): Diesel Particulate Filter (DPF) IN Temperature is not correct

The engine control system has detected an implausible, erratic, or out-of-range signal from the exhaust gas temperature sensor located upstream (at the inlet) of the Diesel Particulate Filter. This condition prevents the system from accurately monitoring exhaust temperatures, which can disable automatic or manual DPF regeneration and eventually lead to a clogged filter.

• L213
• L215
• L216
• L218
• L220
• L223
• L225
• L230
• SR175
• C227
• C232
• C238
• W50C
• W60C
• W70C
• W80C
• SR160
• SR210
• SR220
• SV250
• TR270

1. 1

   Connect a diagnostic tool and view live data for 'DPF IN Temp' to check if the value is stuck, erratic, or implausible (e.g., reading extremely high when the engine is cold)

2. 2

   Look for accompanying voltage codes indicating a hard electrical fault, such as 3175 (DPF IN Temperature Sensor: Out of Voltage - Low) or 3840 (DPF IN Temperature Sensor: Out of Voltage - High)

3. 3

   Inspect the sensor's wiring harness and connector for signs of melting, chafing against the exhaust, corrosion, or disconnection

4. 4

   Use a multimeter to test the sensor's resistance; an open circuit (infinite resistance) or a dead short indicates a failed internal thermistor

1. 1

   Cool Down

   Park the machine on a level surface, turn off the engine, and allow the exhaust system and DPF assembly to cool completely to avoid severe burns.

2. 2

   Locate the Sensor

   Locate the DPF IN (Upstream) Temperature Sensor. It is threaded into the exhaust piping directly before the DPF housing.

3. 3

   Disconnect

   Unplug the sensor's electrical pigtail connector from the main engine harness.

4. 4

   Removal

   Using a suitable wrench or sensor socket, carefully unscrew the faulty temperature sensor from the exhaust pipe. (Tip: Penetrating oil may be required if the sensor is seized from heat cycling).

5. 5

   Preparation

   Apply a small amount of high-temperature anti-seize compound to the threads of the new sensor (if it does not come pre-applied). Ensure no compound gets on the sensor probe itself.

6. 6

   Installation

   Thread the new sensor into the exhaust by hand to prevent cross-threading, then tighten to the OEM torque specification.

7. 7

   Reconnect

   Reconnect the electrical connector, ensuring the locking tab clicks into place securely. Route the wire away from direct heat sources.

8. 8

   Clear Codes & Test

   Turn the ignition on and use your diagnostic tool to clear fault code ENG 1804. Start the engine and initiate a manual/forced DPF regeneration to verify the sensor reads correctly under load and the code does not return.