Case IH F1U – Transmission Controller (Transmission/EDC): Medium Range Solenoid Open Circuit Or Short To Ground

This indicates an electrical failure in the circuit controlling the medium range clutch pack. The controller is detecting that the electrical path to the medium range solenoid is either broken (open circuit) or making unintended contact with the machine's chassis (short to ground).

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• TM115
• TM120
• TM125
• TM130
• TM135
• TM140
• TM150
• TM155
• TM165
• TM175
• TM190

1. 1

   Inspect the medium range solenoid connector (X-642) and Transmission Control Unit connectors (X-091, X-092, X-095) for secure fit, damage, and correct pin position.

2. 2

   Inspect the transmission extension harness where it connects to the main harness for rubbed-through insulation or broken wires.

3. 3

   Measure the resistance across the medium range solenoid coil using a multimeter to check for an open or shorted coil.

1. 1

   Repair Wiring

   If the diagnostic checks reveal a broken wire or damaged connector, repair the harness or replace the connector terminals.

2. 2

   Replace Solenoid

   If the wiring is intact but the solenoid coil failed the resistance test, locate the transmission control valve assembly on the side of the transmission and replace the medium range PWM solenoid valve.

3. 3

   Clear Codes

   Reconnect all harnesses and turn the key to the ON position to ensure the F1U code is no longer active.

4. 4

   Recalibrate Transmission

   Reset the transmission non-volatile memory and recalibrate. Place all shift levers in neutral and block the tractor's wheels (front and rear). Press and hold the High and Low range buttons simultaneously and start the engine. When 'CAL' appears in the transmission display, release the buttons. Set the engine speed to 1200 RPM (± 100 RPM) and follow the on-screen prompts to cycle through and complete the clutch calibration.