Case IH 19897 – Engine Control Unit (ECU): High pressure intercooler outlet pressure sensor voltage higher than expected

This fault indicates that the sensor measuring the air pressure at the outlet of the high-pressure intercooler is reporting a voltage value that exceeds the maximum expected threshold. This typically points to a 'Voltage Above Normal / Shorted to high source' electrical issue, an actual overboost condition, or a blockage in the charge-air system.

• Tier 4b
• 240 Series Axial-Flow Combines

1. 1

   Verify the Code: Confirm whether the scan tool is reading 19897 or the officially documented 19900 / 1A93.

2. 2

   Visual Inspection for Leaks: Check for air leaks around the intercooler outlet pressure sensor mounting point and all adjacent charge air hoses.

3. 3

   Wiring & Circuit Check: Inspect the sensor wiring harness for a 'short to high source' (voltage above normal). Check for disconnected lines or short circuits.

4. 4

   Clear and Retest: Clear any stored fault codes relating to boost/intercooler pressure and perform a short drive/operation cycle to confirm if the code returns immediately (hard electrical fault) or under load (mechanical/pressure issue).

1. 1

   Locate the Sensor

   Identify the high-pressure intercooler outlet pressure sensor (also known as a boost pressure sensor) on the engine's charge-air piping.

2. 2

   Inspect Hoses and Clamps

   Physically examine the intercooler hoses. Tighten any loose clamps and replace any hoses that show signs of cracking, swelling, or leaking.

3. 3

   Inspect the Connector

   Disconnect the 3-pin sensor connector. Inspect the terminals for corrosion, moisture, or pushed-out pins.

4. 4

   Repair the Harness

   If the diagnostic tests revealed a short to voltage in the wiring harness, repair or replace the affected section of the harness.

5. 5

   Replace the Sensor

   If the wiring is intact, no physical blockages or leaks are present, and the voltage remains out of range, replace the intercooler outlet pressure sensor.

6. 6

   Relearn Cycle

   Reconnect the sensor and clear the fault codes. Allow the Engine ECU one or two complete warm-up and cool-down cycles so the system can relearn the sensor performance and verify the repair.