Case IH 117 – Transmission Controller (TRANS / TCU): C3-4 clutch solenoid coil or its wiring shorted to power

This code is triggered when the transmission controller commands the C3-4 clutch valve coil driver OFF, but the system still senses current flowing through the driver. This indicates that either the solenoid coil has failed internally, or the wiring harness is shorted to a +12V power source.

• MX Magnum
• MX Magnum Series
• TG Series
• Steiger Series
• Puma Series
• Magnum 235–340 (Series 4)

1. 1

   Inspect the wiring harness from the transmission controller to the C3-4 clutch solenoid for rubbed-through insulation, pinched wires, or melted loom that could be shorting the circuit to a 12V power source.

2. 2

   Disconnect the C3-4 solenoid and the transmission controller to check the pins for corrosion, moisture ingress, or bent terminals that could bridge power to the solenoid circuit.

3. 3

   Use a multimeter to measure the resistance across the C3-4 solenoid coil pins. If the resistance is near zero, the solenoid is internally shorted.

4. 4

   Test the transmission controller output pin for the C3-4 clutch to see if it is continuously supplying voltage when commanded off, which indicates an internal short (failed driver stuck closed) in the controller.

1. 1

   Prep the Machine

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the battery to prevent electrical spikes. Relieve any residual hydraulic pressure.

2. 2

   Locate the Valve Body

   Locate the transmission control valve body (usually mounted on the side of the transmission housing) and identify the C3-4 clutch solenoid.

3. 3

   Remove the Solenoid

   Disconnect the electrical harness from the solenoid. Unbolt the solenoid from the valve body. Be prepared to catch a small amount of hydraulic fluid.

4. 4

   Clean and Inspect

   Clean the mounting surface on the valve body. Ensure no debris enters the hydraulic circuit.

5. 5

   Install the New Solenoid

   Mount the replacement solenoid and torque the retaining bolts to OEM specifications. Reconnect the electrical harness.

6. 6

   Address Wiring/Controller (If Applicable)

   If your diagnostics pointed to the harness or the TCU, repair the damaged wire section or replace the transmission controller.

7. 7

   Recalibrate

   Reconnect the battery, start the tractor, and clear the fault codes. If the transmission controller was replaced or if shifting is harsh, use the dealer service tool to perform a transmission clutch calibration.