New Holland ENG 3995 – Engine ECU (ISM-IDI ENGINE): Diesel Particulate Filter (DPF) OUT Temperature is over 800 °C (1472 °F)

This code triggers when the exhaust gas temperature exiting the DPF exceeds the critical safety threshold. This condition can be caused by a genuine exhaust overheating event (such as uncontrolled fuel burning/runaway regeneration in a clogged DPF) or, more commonly, a failure of the DPF OUT temperature sensor or its wiring circuit sending an artificially high voltage signal to the computer.

• L213
• L215
• L216
• L218
• L220
• L223
• L225
• L230
• C227
• C232
• C238
• W50C through W300C series
• B90B
• B100B

1. 1

   Check for Related Voltage Codes: Scan the Engine ECU for related sensor circuit codes like 1802 (Out of Voltage - Low), 1803 (Out of Voltage - High), or 1806 (Temperature is not correct).

2. 2

   Live Data Monitoring: Connect a diagnostic scan tool and read the live data for the DPF OUT Temperature. If the sensor reads >800 °C (1472 °F) when the engine is completely cold, the sensor is shorted internally or there is a wiring harness short.

3. 3

   Visual Wiring Inspection: Inspect the wiring harness leading to the DPF OUT temperature sensor for melted insulation, chafing against the exhaust pipe, or corrosion inside the connector.

4. 4

   DPF Restriction Check: Check the DPF differential pressure sensor readings to determine if the DPF is severely overloaded or clogged, causing excessive heat buildup.

1. 1

   Cool Down

   Ensure the machine is parked on a level surface, the engine is turned off, and the exhaust system has completely cooled to prevent severe burns.

2. 2

   Locate the Sensor

   Locate the DPF OUT temperature sensor, which is threaded into the exhaust piping immediately downstream of the Diesel Particulate Filter canister.

3. 3

   Disconnect Wiring

   Carefully unplug the sensor's electrical connector from the main engine wiring harness.

4. 4

   Remove the Sensor

   Using a specialized sensor socket or a properly sized wrench, carefully loosen and remove the sensor from the exhaust pipe. (Tip: Penetrating oil may be required if the sensor is seized from extreme exhaust heat).

5. 5

   Prepare the New Sensor

   Apply a small amount of high-temperature anti-seize compound to the threads of the new sensor, being extremely careful not to get any compound on the sensor probe tip itself.

6. 6

   Install

   Thread the new sensor in by hand to prevent cross-threading, then tighten it to the manufacturer's specified torque.

7. 7

   Reconnect and Clear

   Reconnect the electrical harness. Use your diagnostic scan tool to clear the ENG 3995 fault code from the Engine ECU.

8. 8

   Test

   Start the engine and monitor the live exhaust temperature data to ensure the new sensor is reading ambient/normal operating temperatures.