Case IH 19901 (DTC 2B93) – Engine ECU: High pressure intercooler outlet pressure sensor voltage lower than expected.

This indicates that the signal voltage returning from the intercooler outlet pressure sensor (often referred to as a boost pressure sensor) has dropped below the acceptable minimum threshold. This is typically caused by an open circuit, a short to ground in the sensor wiring, or an internal failure of the sensor itself.

• MAXXUM T4E
• 240 Series Axial-Flow Combines
• 7240
• 8240
• 9240

1. 1

   Connect the Case IH Electronic Service Tool (EST) to monitor the live voltage reading of the high pressure intercooler outlet pressure sensor.

2. 2

   Inspect the wiring harness leading to the intercooler outlet pressure sensor for chafed wires, melted insulation, or pinched lines that could cause a short to ground.

3. 3

   Disconnect the sensor and inspect the pins on both the sensor and the harness side for pushed-back pins, corrosion, or moisture intrusion.

4. 4

   With the key ON and engine OFF, use a multimeter to check the harness connector for proper 5V reference voltage and a good ground. If the reference voltage is missing, the issue is in the wiring harness or the Engine ECU. If the reference voltage and ground are good, the sensor itself has likely failed internally.

1. 1

   Power down machine

   Power down the machine, turn off the battery disconnect switch, and allow the engine to cool.

2. 2

   Locate sensor

   Locate the high pressure intercooler outlet pressure sensor. It is mounted on the engine air intake tract, specifically at the outlet of the high-pressure intercooler leading into the intake manifold.

3. 3

   Disconnect harness

   Depress the locking tab and disconnect the electrical harness from the sensor.

4. 4

   Remove sensor

   Unthread or unbolt the faulty sensor from the intercooler outlet piping/manifold.

5. 5

   Clean mounting port

   Clean the mounting port to ensure no debris falls into the engine intake.

6. 6

   Install new sensor

   Install the new pressure sensor and tighten it to the manufacturer's specified torque (do not overtighten, as this can damage the sensor element).

7. 7

   Reconnect harness

   Reconnect the electrical harness, ensuring the locking tab clicks into place.

8. 8

   Clear fault code

   Turn on the battery disconnect, connect the EST, and clear the inactive 19901 (2B93) fault code from the Engine ECU.

9. 9

   Verify repair

   Start the engine and verify that the code does not return and that the engine operates without derating or power loss.