Case IH 419 – Engine Control Module (ECM) / Engine ECU: Boost Pressure data invalid

The Engine Control Module (ECM) has detected an error or an invalid signal coming from the Intake Manifold Pressure Sensor (Boost Pressure Sensor or MAP sensor). This typically causes the engine to de-rate to a 'no air' setting, resulting in a severe loss of power, rough idle, surging, or excessive fuel consumption.

• MX Magnum
• STX Steiger
• Case IH MX Magnum Series Tractors
• Case IH Steiger Series
• Case IH Axial-Flow Combines
• Equipment utilizing 8.3L, 9L, 11L (QSM11), and 15L engines

1. 1

   Inspect the Boost Pressure Sensor (Intake Manifold Pressure Sensor) and its wiring harness for chafed wires, melted insulation, or physical damage to the sensor body.

2. 2

   Disconnect the sensor and inspect the pins for bent, loose, pushed-back, or corroded pins (specifically the signal pin, often pin 39 depending on the exact engine harness).

3. 3

   Verify that the sensor is receiving the correct reference voltage from the ECM and that the ground circuit is intact.

4. 4

   Check the continuity of the signal wire from the sensor connector back to the ECM to rule out an open or short circuit.

1. 1

   Power Down

   Turn off the machine and disconnect the battery ground to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate the Boost Pressure Sensor, which is mounted directly on the intake manifold.

3. 3

   Harness Repair (If Applicable)

   If the diagnostic checks revealed damaged wiring or a faulty connector, repair the wiring harness or splice in a new connector pigtail.

4. 4

   Sensor Replacement

   If the wiring is intact and the sensor is internally shorted or sending invalid data, replace the sensor. Unplug the electrical connector, unbolt or unthread the faulty sensor from the intake manifold, clean the mating surface, install the new sensor (ensure any O-rings or seals are properly seated), tighten to OEM torque specs, and reconnect the electrical harness.

5. 5

   Clear Codes

   Reconnect the battery, turn the key to the ON position, and use a diagnostic scan tool (like Jaltest or the Case IH Electronic Service Tool) to clear the inactive 419 fault code.

6. 6

   Test Run

   Start the engine and verify that the yellow warning light is off and the engine no longer de-rates under load.