Case IH 19900 – Engine Control Unit (ECU): High pressure intercooler outlet pressure sensor voltage higher than expected

The engine control module is receiving a voltage signal from the high pressure intercooler outlet pressure sensor that exceeds the normal, calibrated operating range.

• Tier 4b
• 240 Series Axial-Flow Combines
• 7240
• 8240
• 9240

1. 1

   Inspect the wiring harness leading to the high pressure intercooler outlet pressure sensor for chafed wires, melted insulation, or physical damage

2. 2

   Disconnect the sensor and inspect the pins for corrosion, moisture, or pushed-back terminals

3. 3

   Test the sensor ground circuit for an open circuit (high resistance)

4. 4

   Test the signal wire for a short to a power source (voltage present when it shouldn't be)

5. 5

   Monitor the live voltage reading of the sensor using the Case IH Electronic Service Tool (EST). If it reads 5V while unplugged, the harness is shorted. If it drops to 0V when unplugged, the sensor is likely internally shorted

1. 1

   Turn off the combine, lower all attachments, and remove the key from the ignition.

2. 2

   Locate the high pressure intercooler outlet pressure sensor (typically mounted on the charge air cooler piping or intake manifold of the FPT engine).

3. 3

   Disconnect the electrical connector from the sensor.

4. 4

   If wiring faults (open ground or short to power) were found during diagnostics, repair the damaged section of the harness or replace the connector pigtail.

5. 5

   If the wiring is intact and tests within specification, remove the faulty sensor using the appropriate socket/wrench.

6. 6

   Install the new high pressure intercooler outlet pressure sensor and torque to OEM specifications.

7. 7

   Reconnect the electrical harness.

8. 8

   Connect the Case IH Electronic Service Tool (EST) to clear the active/stored DTC 19900 from the engine controller.

9. 9

   Start the engine and verify that the fault code does not return and that the machine has full power (no derate).