Case IH 56035 – Transmission Controller (TRANS): 1R (1st Reverse) Valve Coil circuit is open or shorted to ground when the valve is ON

The transmission controller measures the current draw and voltage from the 1R clutch solenoid circuit. When the 1R clutch solenoid coil is commanded ON, the voltage on the low side of the coil is lower than expected, or the current draw is below the acceptable limit.

• STX Steiger
• Puma Series (115-260)
• Magnum Series (180-240)
• Steiger / STX Series
• Maxxum Series (100-150)
• Farmall Series (40-120U)
• Optum Series
• Vestrum Series
• MXM Series
• MXU Series

1. 1

   Retrieve, record, and clear any fault codes before beginning physical diagnostics or attempting calibration.

2. 2

   Visually inspect the wiring harness and connectors running between the transmission controller and the 1R clutch solenoid for chafing, breaks, or loose pins.

3. 3

   Verify that power is available from the neutral latch relay to ensure there isn't an open circuit in the solenoid's main power wire.

4. 4

   Use a multimeter to test the 1R clutch solenoid coil resistance to see if it has failed open or is shorted to ground (especially if the issue is temperature-sensitive).

1. 1

   Isolate the Fault

   Based on the diagnostic checks, determine if the fault lies in the wiring harness or the solenoid itself.

2. 2

   Repair Wiring

   If the wire between the 1R clutch solenoid and the transmission controller is shorted to ground or open, repair or replace the damaged section of the harness.

3. 3

   Replace the Solenoid

   If the solenoid coil tests open or shorted (or fails when it gets up to operating temperature), safely relieve any hydraulic pressure, disconnect the electrical connector, unthread the faulty 1R clutch solenoid valve, and install the replacement part.

4. 4

   Clear Codes

   Turn the key on and clear the fault codes from the Transmission Controller.

5. 5

   Transmission Calibration

   After replacing transmission components, a transmission calibration must be performed. Enter the "Trans Setup" menu on the display, ensure the inching pedal is in a valid range, and follow the on-screen prompts to calibrate the clutches.