Case IH 3171 – Engine Controller (Engine ECU / ECM): DPF Outlet Pressure Sensor Low Voltage

The signal voltage returning from the DPF outlet pressure sensor to the control module has dropped below the minimum acceptable range, typically caused by a short to ground in the sensor circuit, an open circuit/broken wire, or a complete internal failure of the sensor itself.

• skid steer
• SR160
• SR220
• SR250
• SV250
• SV300
• TR320
• TV380
• TV450B
• 588H

1. 1

   Inspect the wiring harness leading to the DPF Outlet Pressure Sensor for chafing, melting, or physical damage

2. 2

   Disconnect the sensor and check the pins for corrosion, moisture, or loose terminals

3. 3

   Use a multimeter to check for a short to ground or an open load on the sensor signal wire between the sensor connector and the Engine ECU

4. 4

   Verify that the sensor is receiving the correct reference voltage (typically 5V) and has a solid ground connection

1. 1

   Turn off the equipment, remove the key, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the DPF Outlet Pressure Sensor on the exhaust aftertreatment system.

   Usually mounted near the DPF housing with pressure lines routed to the exhaust pipe.

3. 3

   Disconnect the electrical harness connector from the sensor.

4. 4

   Repair the damaged section of the harness or replace the connector.

   Perform this if diagnostic tests revealed a wiring fault (short to ground or open circuit).

5. 5

   Disconnect the pressure hoses/fittings from the faulty sensor and unbolt it from its mounting bracket.

   Perform this if the wiring is intact, indicating the sensor has failed.

6. 6

   Install the new DPF Outlet Pressure Sensor, reconnect the pressure lines securely, and plug in the electrical connector.

7. 7

   Reconnect the battery.

8. 8

   Use an Electronic Service Tool (EST) to clear the fault codes.

   Run the engine and monitor the DPF pressure data to ensure the voltage is now within the normal operating range.