Case IH 19414 – Engine Control Module (ECM / ECU): Crankcase pressure Sensor 2 (in blow by hose) voltage is lower than expected

The voltage signal returning from the sensor to the control module has dropped below the minimum acceptable threshold (typically below 0.5V on a 5V reference circuit). This condition generally points to an electrical fault, such as a short to ground in the signal wire, an open circuit, a disconnected plug, or an internally shorted/failed sensor.

• Tier 4b
• Case IH agricultural equipment
• Case Construction Equipment (N-Series loaders)

1. 1

   Visually inspect the crankcase breather/blow-by hose for physical damage, blockages, or a disconnected hose.

2. 2

   Unplug the Crankcase Pressure Sensor 2 connector and inspect for water intrusion, corrosion, pushed-back pins, or damaged terminals.

3. 3

   Trace the wiring harness from the sensor back to the Engine ECU, looking for chafing, melted insulation, or pinched wires that could cause a short to ground.

4. 4

   With ignition ON and engine OFF, use a multimeter to verify the sensor is receiving a steady 5V reference voltage and has a solid ground at the connector.

5. 5

   Check the continuity of the signal wire between the sensor connector and the corresponding pin on the Engine ECU to rule out an open circuit.

1. 1

   Power Down

   Turn off the machine's ignition and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate Crankcase Pressure Sensor 2, which is mounted inline or attached directly to the crankcase blow-by ventilation hose (often near the turbocharger air inlet or valve cover breather).

3. 3

   Disconnect Wiring

   Carefully depress the locking tab and unplug the electrical connector from the sensor.

4. 4

   Remove the Sensor

   Remove the retaining fasteners (typically 8mm or 10mm bolts) or release the quick-connect tabs. Pull the sensor out of the housing/hose carefully to avoid snapping the plastic tabs or damaging the hose tee.

5. 5

   Install the New Sensor

   Seat the new sensor into the blow-by hose assembly. Install and tighten the retaining bolts (standard OEM torque for these plastic-housed sensors is generally around 8 Nm / 70 in-lbs).

6. 6

   Reconnect

   Plug the electrical connector back in until it clicks securely.

7. 7

   Clear and Verify

   Reconnect the battery, use a diagnostic scan tool to clear the inactive 19414 fault code, and run the engine to verify that the code does not return and that crankcase pressure reads normally.