Case IH t4F – EIC (Electronic Instrument Cluster) and Transmission/EDC (Electronic Draft Control) Microprocessor: Coolant Temperature Sensor (PHY), Data Incorrect

The control module is receiving an implausible, erratic, or invalid signal from the physical engine coolant temperature sensor.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• TM120
• TM130
• TM140
• TM155

1. 1

   Verify that the engine coolant is at the proper level in the header tank to prevent air exposure causing erratic readings.

2. 2

   Inspect the wiring harness and electrical connector leading to the coolant temperature sensor for chafed wires, melted insulation, or corrosion.

3. 3

   Perform a sensor plausibility check using the H-Menu or a scan tool by comparing the Engine Coolant Temperature to the Transmission or Engine Oil Temperature when the tractor is completely cold.

1. 1

   Preparation

   Park the tractor on a level surface, turn off the engine, and remove the key. Allow the engine to cool down completely to prevent severe burns from hot, pressurized coolant.

2. 2

   Locate the Sensor

   Locate the coolant temperature sensor on the engine block or thermostat housing (typically near the upper radiator hose connection).

3. 3

   Disconnect Wiring

   Carefully depress the locking tab on the electrical connector and pull it free from the sensor.

4. 4

   Catch Spillage

   Place a clean drain pan directly under the sensor area to catch the small amount of coolant that will escape when the sensor is removed.

5. 5

   Remove the Sensor

   Using a deep socket or wrench, unthread the faulty coolant temperature sensor from the housing.

6. 6

   Install the New Sensor

   Thread the new sensor into the housing. If the sensor does not have a pre-installed O-ring or thread sealant, apply a small amount of liquid thread sealant to the threads. Tighten to the OEM torque specification (do not overtighten, as it is a brass fitting).

7. 7

   Reconnect and Refill

   Plug the electrical connector back in until it clicks. Top off the engine coolant in the header tank to replace any fluid lost during the swap.

8. 8

   Test

   Start the tractor and let it reach operating temperature. Check the sensor area for leaks. Verify that the t4F fault code has cleared from the instrument cluster display.