Case IH F-2630-02 - ECU – Engine Control Unit (ECU): Plausibility check error of the Charge Air Cooler (CAC) / Fresh Air Temperature Sensor at cold start

When the machine is cold, the Engine Control Unit (ECU) compares the readings from various temperature sensors (coolant, ambient air, intake manifold, and charge air cooler). If the Charge Air Cooler temperature sensor reports a value that deviates significantly from the other sensors or the expected ambient temperature during a cold start, the ECU flags the data as implausible and logs this FMI 02 fault.

• MAGNUM AFS Connect
• Magnum Series
• Magnum 400 AFS Connect
• Magnum 235–340
• Steiger Series
• Farmall Series

1. 1

   Connect a diagnostic service tool and view live data for all engine temperature sensors (Intake Air, Coolant, Charge Air Cooler, and Battery) before starting a cold engine to check for skewed CAC readings.

2. 2

   Inspect the wiring harness and the connector at the Charge Air Cooler temperature sensor for water intrusion, corrosion, loose pins, or chafed wires.

3. 3

   Ensure the charge air cooler and radiator fins are not severely plugged with debris, which can cause retained heat or erratic airflow readings.

1. 1

   Preparation

   Ensure the machine is parked on a level surface, the engine is turned off, and the system is completely cooled down. Disconnect the battery ground cable to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate the Charge Air Cooler (CAC) / Intercooler temperature sensor, typically mounted on the intake piping just after the intercooler and before the intake manifold.

3. 3

   Disconnect and Remove

   Unplug the electrical connector from the sensor. Use a wrench to carefully unthread the faulty temperature sensor from the charge air piping.

4. 4

   Install the New Sensor

   Thread the new OEM temperature sensor into the port. Tighten to the manufacturer's specified torque (do not overtighten, as the sensor body is fragile).

5. 5

   Reconnect

   Plug the electrical connector back in, ensuring the locking tab clicks into place. Reconnect the battery ground cable.

6. 6

   Clear Codes and Test

   Turn the ignition on and use the Electronic Service Tool (EST) to clear the F-2630-02 fault code. Perform a cold start and verify via live data that the sensor is now reading the correct ambient temperature and the code does not return.