New Holland ENG 1806 – Engine Control Module (ECM) / ISM-IDI ENGINE: Diesel Particulate Filter (DPF) OUT Temperature is not correct.

This code indicates that the temperature reading coming from the sensor located downstream (at the outlet) of the Diesel Particulate Filter is out of the expected range or not correlating with the engine's operating conditions. This can prevent the machine from performing a proper DPF regeneration and may force the engine into a derated (limp) mode.

• L213
• L215
• L218
• L220
• SR175
• SV185
• C227
• C238
• TR340
• L230

1. 1

   Connect a diagnostic scan tool and monitor the live data for the DPF OUT temperature sensor. On a cold engine, the reading should be close to ambient temperature. As the engine warms up, the temperature should rise gradually. A reading stuck at an extreme maximum or minimum points to a failed sensor or an electrical short/open circuit.

2. 2

   Inspect the wiring harness leading to the DPF OUT temperature sensor. Look for melted wires, chafing, or severe vibration damage.

3. 3

   Disconnect the sensor and check the pins for corrosion or fluid contamination.

4. 4

   Inspect the exhaust piping around the Diesel Oxidation Catalyst (DOC) and DPF for leaks, which can cause abnormal temperature readings.

1. 1

   Cool Down

   Park the machine on a flat surface, turn off the engine, and allow the exhaust system to cool completely. DPF temperatures can exceed 900°C (1650°F) during operation and regeneration.

2. 2

   Locate the Sensor

   Locate the DPF OUT temperature sensor on the exhaust aftertreatment assembly. It will be positioned downstream of the main DPF canister.

3. 3

   Disconnect Wiring

   Detach the sensor's electrical connector from the main wiring harness and unclip any retaining clamps holding the wire.

4. 4

   Remove the Sensor

   Using a union nut wrench (typically 14mm) or a specialized sensor socket, carefully loosen and remove the faulty temperature sensor from the exhaust pipe. Note: Be careful not to break the sensor off in the exhaust housing.

5. 5

   Install the New Sensor

   Apply a small amount of high-temp anti-seize compound to the threads of the new sensor (if it does not come pre-applied). Thread it into the exhaust pipe and tighten it securely.

6. 6

   Reconnect

   Reconnect the electrical connector to the harness and secure the wire in its original retaining clips to prevent vibration damage.

7. 7

   Clear Codes and Test

   Use a diagnostic scan tool to clear the ENG 1806 fault code. Start the engine, monitor the live temperature data to ensure the new sensor is reading correctly, and perform a forced DPF regeneration if the system requires it to clear soot accumulation.