New Holland ENG 3170 – Engine ECU (ISM-IDI ENGINE): Diesel Particulate Filter (DPF) OUT Temperature is Over 700 °C (1292 °F)

This code triggers when the exhaust gas temperature exiting the Diesel Particulate Filter exceeds the safe operating threshold of 700 °C, which can indicate an uncontrolled regeneration event, a severely clogged filter, or a faulty temperature sensor sending an erroneously high reading.

• L213
• L216
• L220
• L223
• L230
• C245
• SR175
• SV series
• TR/TV series
• B90B
• B100B
• B110C
• B115C

1. 1

   Check for accompanying voltage codes (e.g., 1802, 1803, or 1806) that indicate a wiring short, open circuit, or failed sensor rather than a physical overheating issue.

2. 2

   Visually inspect the wiring harness leading to the DPF OUT temperature sensor (Exhaust Gas Temp Sensor #2). Look for melted wires, corrosion, or loose connectors (specifically connectors X-476 or X-477).

3. 3

   Check for DPF restriction codes (e.g., 3426 DPF Level 1 Overloaded or 3427 Flow resistance low) to see if a severely clogged DPF is causing abnormal exhaust temperatures.

4. 4

   Physically inspect the DOC (Diesel Oxidation Catalyst) and DPF assembly to ensure they are not physically damaged or glowing red hot during operation.

1. 1

   Locate the Sensor

   Locate the DPF assembly. Identify the DPF OUT temperature sensor, which is designated in New Holland service manuals as 'Exhaust Gas Temp Sensor #2' (mounted on the outlet side of the DPF).

2. 2

   Disconnect the Harness

   Carefully disconnect the electrical connector for the temperature sensor.

3. 3

   Remove the Sensor

   Using a crowfoot wrench, loosen the temperature sensor tightening nut. OEM manuals explicitly warn to use a crowfoot wrench to prevent twisting or damaging the sensor body or the adjacent differential pressure pipes.

4. 4

   Install the New Sensor

   Thread the new temperature sensor into the DPF housing and tighten it to the specified torque using the crowfoot wrench.

5. 5

   Reconnect

   Reconnect the sensor to the engine wiring harness.

6. 6

   Clear the Code

   Use the New Holland Electronic Service Tool (EST) or a compatible CAN-bus DTC eraser to clear code 3170 from the Engine ECU.

7. 7

   Test Run

   Start the machine and monitor the DPF exhaust temperatures via the diagnostic tool to ensure they remain within the normal operating range (below 700 °C).