Case IH F-105-31 - ECU – Engine Control Module (ECM / ECU): Torque limitation due to excessive intake air temperature

This fault indicates that the intake air temperature (the air entering the engine's intake manifold after passing through the turbocharger and charge air cooler) has exceeded the maximum safe operating threshold. To protect the engine from severe thermal damage or pre-ignition, the control module automatically enforces a "derate" state, limiting the engine's fuel injection and overall torque output.

• MAGNUM AFS Connect
• 240 Series Combines
• MX Series
• TG Series
• Steiger Series
• Farmall Series
• 70A
• 85A
• 95U
• 105U
• 115U

1. 1

   Inspect the Cooling Package: Check the charge air cooler (intercooler) and radiator for blockages caused by dirt, chaff, or debris. Restricted airflow is the most common mechanical cause of excessive intake temperatures.

2. 2

   Verify Sensor Data: Use a diagnostic tool to monitor the live data from the Intake Manifold Temperature Sensor. Compare the reading to ambient temperature when the engine is cold to check for sensor drift or erratic data.

3. 3

   Inspect Wiring and Connectors: Check the wiring harness leading to the MAP/IAT sensor for chafing, shorts to ground, or disconnected pins.

4. 4

   Check for Related Codes: Look for accompanying voltage codes (e.g., "Intake manifold temperature sensor voltage is higher than expected") which would point directly to an electrical failure rather than an actual overheating event.

1. 1

   Clean the Coolers

   Thoroughly blow out or wash the engine cooling package (radiator and charge air cooler) to restore proper airflow.

2. 2

   Inspect the Sensor

   Locate the Intake Air Temperature/Pressure sensor on the engine inlet manifold. Remove it and inspect the sensor tip for heavy soot or oil fouling.

3. 3

   Replace the Sensor (if faulty)

   If the sensor is damaged, fouled, or failed the diagnostic data check, replace it with a new OEM sensor. Ensure the O-ring is properly seated to prevent boost leaks and keep out contaminants.

4. 4

   Clear Codes and Test

   Clear the fault codes from the ECM. Run the machine under load to verify that the intake air temperature remains within normal limits and that the torque limitation (derate) has been lifted.