Case IH F44 – Transmission Control Unit (TCU): Medium/Reverse Range Synchronizer Potentiometer Out Of Calibrated Range

This code indicates that the transmission controller is receiving a signal from the medium/reverse range synchronizer potentiometer that falls outside of its expected, calibrated voltage parameters.

• MXM
• MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190

1. 1

   Inspect the medium/reverse range synchronizer potentiometer connector (X-667) and the CCU/Transmission controller connector (X-094) for secure connection, damage, correct pin position, and tight fit.

2. 2

   Disconnect the potentiometer connector (X-667), turn the ignition switch to the ON position, and measure the voltage at the connector to ensure it is receiving the standard 5-Volt reference from the controller.

3. 3

   Check the medium range clutch solenoid by measuring the resistance between solenoid terminal 1 and terminal 2. The normal resistance reading should be between 8 to 11 Ohms.

1. 1

   Wiring Repair

   If a fault is indicated during the visual inspection of the connectors or wiring harness, repair or replace the damaged wiring/pins as required.

2. 2

   Solenoid Replacement

   If the resistance of the medium range clutch solenoid is not between 8 - 11 Ohms, remove and replace the solenoid.

3. 3

   Potentiometer Replacement

   If the wiring, 5V reference, and solenoid are all in good working order but the F44 code persists, the Medium/Reverse Range Synchronizer Potentiometer itself has likely failed and must be replaced.

4. 4

   Transmission Calibration

   After replacing the potentiometer, solenoid, or any transmission controller, you must perform a full transmission calibration. The range potentiometers are automatically calibrated during the calibration of the transmission clutches.