Case IH 118 – Transmission Controller (TCU): 1R clutch solenoid is shorted to +12 Volts (current sensed while driver is off) / 1R clutch solenoid coil is turned on and voltage on the low side of the coil is higher than expected.

The controller is detecting current draw or higher-than-expected voltage on the 1R clutch solenoid circuit when the circuit should be off. This fault code is typically recorded whenever the transmission is shifted into forward gears 4, 11, 12, 16LO, or 16HI, or during valve calibration.

• MX Magnum
• STX Steiger
• Steiger / STX Series (STX 325, 435, 9270, 9280, 9310, 9330, Panther, Bearcat, Cougar)
• Puma Series
• Maxxum Series (MXU110, 115)
• Magnum Series
• Legacy Case IH Tractors (5120, 5130, 5140, 5220, 5230, 5240, 5250)

1. 1

   Locate the Transmission Controller underneath the fuse/relay panel inside the cab.

2. 2

   Inspect the wiring harness running from the transmission controller to the 1R clutch solenoid on the transmission valve body for rubbed-through insulation, pinched wires, or melted loom that could cause a short to +12V power.

3. 3

   Disconnect the 1R clutch solenoid and use a multimeter to measure the resistance across the coil pins. Compare it to OEM spec to determine if the coil is internally shorted (especially if the issue is temperature-sensitive).

4. 4

   With the solenoid and controller disconnected, check for continuity to power (+12V) on the signal wire to test the harness.

5. 5

   If the wiring harness and the solenoid both test perfectly fine, check the transmission controller itself, as it may have a failed internal driver.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Repair Wiring

   If a short to power was found in the harness during diagnostics, repair the damaged section of the wire and protect it with new conduit/loom.

3. 3

   Clean Valve Block

   Clean the area around the transmission control valve block to prevent debris from entering the transmission.

4. 4

   Disconnect Solenoid

   Disconnect the electrical connector from the 1R clutch solenoid.

5. 5

   Remove Solenoid

   Unbolt and remove the faulty solenoid valve from the transmission block.

6. 6

   Install New Solenoid

   Lubricate the O-rings on the new solenoid with clean transmission fluid and install it into the valve block. Torque to OEM specifications.

7. 7

   Clear Codes

   Reconnect the battery. Enter the tractor's diagnostic menu to retrieve, record, and clear the fault codes.

8. 8

   Perform Transmission Calibration

   Warm the tractor up (engine speed to 2000 RPM). Use the PROG and DECR keys on the armrest/display to enter the 'TRANS SETUP' menu. Follow the on-screen prompts to calibrate the clutch pedal (Pedal Dn / Pedal Up) and the transmission valves.