Case IH F-519551-02 - ECU – Engine Control Module (ECM / Engine ECU): More than one engine temperature sensor is implausible at cold start only.

During a cold soak (when the machine has been turned off long enough for the engine to cool down to ambient temperature), the control module compares the readings of all engine temperature sensors. If more than one of these sensors reports a temperature that significantly deviates from the others or the ambient air temperature, the system flags the readings as implausible.

• MAGNUM AFS Connect
• Case IH Farmall Series (40, 45, 50, 85C, 95C, 105C, 115U, 120U)
• Case IH Magnum Series (180, 200, 240, 340, 380)
• Case IH Steiger Series
• Case IH Maxxum MX Series
• Case IH Combines (7120, 8010, 9010)

1. 1

   Verify Cold Soak: Ensure the machine has been sitting with the engine off for at least 8–12 hours so that all fluids and metals have equalized to the ambient outside temperature.

2. 2

   Live Data Comparison: Connect a diagnostic scan tool and pull up the live data for all temperature sensors (Engine Coolant, Engine Oil, Intake Manifold Air, Fuel, and DEF/AdBlue tank temperature).

3. 3

   Identify the Outliers: Compare all sensor readings to the actual ambient temperature. Identify which specific sensors are reading out of range (e.g., reading -40°C or 150°C when it is 20°C outside).

4. 4

   Inspect Wiring and Connectors: Before condemning a sensor, inspect the wiring harness and connectors for the outlier sensors. Look for corrosion, moisture intrusion, chafed wires, or loose pins, which can cause false resistance readings.

5. 5

   Resistance Testing: Disconnect the suspect sensor(s) and measure the internal resistance with a multimeter, comparing the values against the OEM temperature-to-resistance chart for that specific sensor.

1. 1

   Prep the Machine

   Park the machine on a level surface, turn off the engine, and disconnect the negative battery cable.

2. 2

   Relieve Pressure

   Slowly remove the radiator cap to relieve any residual cooling system pressure.

3. 3

   Drain Fluid (Optional but Recommended)

   Place a clean drain pan under the radiator or engine block and drain enough coolant to bring the fluid level below the sensor port to prevent spills.

4. 4

   Disconnect Sensor

   Locate the faulty temperature sensor on the engine block or thermostat housing. Depress the locking tab and carefully unplug the electrical connector.

5. 5

   Remove Sensor

   Using a deep socket or wrench, unthread the faulty sensor from the engine block.

6. 6

   Install New Sensor

   Apply a liquid thread sealant or Teflon tape to the threads of the new sensor (if it does not come pre-coated). Thread it in by hand to prevent cross-threading, then torque it to the OEM specification.

7. 7

   Reconnect

   Plug the electrical connector back into the new sensor until it clicks securely.

8. 8

   Refill Fluids

   Refill the engine coolant to the proper level and reinstall the radiator cap.

9. 9

   Clear Codes

   Reconnect the battery, turn the ignition to the ON position (engine off), and use a diagnostic tool to clear the F-519551-02 / 19202 fault code.

10. 10

    Test

    Start the engine and monitor the live data to ensure the new sensor is reading accurately as the engine warms up. Check for leaks around the new sensor threads.