Case IH 517962-00 - DEC – Transmission Controller: Transmission Low Clutch Solenoid maximum calibration current limit was exceeded

During the transmission calibration process, the transmission controller measures the electrical current required to actuate the low clutch solenoid and apply the clutch pack. If the current exceeds the maximum allowable limit, it typically means the circuit is shorted to power (+12 Volts). In a calibration context, a 'Cal Low' error can also indicate that an abnormal amount of current (often too little) was required to apply the clutch pack, preventing the controller from successfully storing a valid calibration value.

• MAGNUM AFS Connect
• Case IH Magnum Series (Magnum 215, 235, 260, 340, MX210)
• Case IH MXM Series (MXM 120, 130, 140, 155, 175, 190)

1. 1

   Warm the transmission oil to operating temperature by driving the tractor and shifting through gears (e.g., 5th through 14th and reverse).

2. 2

   Verify the regulated transmission pressure (target specifications are generally around 2300 kPa @ 1500 RPM or 2070 kPa @ 1000 RPM).

3. 3

   Ensure the regulated circuit accumulator is properly charged (typically 130-140 psi @ 70°F).

4. 4

   Perform the 'Swap Test': Swap the electrical connectors between the Mid Clutch Solenoid and the Low Clutch Solenoid, then run the 'Low Cal' procedure. If the error follows the solenoid, the solenoid is faulty. If it persists on the same circuit, the issue is in the wiring or controller.

5. 5

   Visually inspect the wiring harness routing from the transmission controller down to the solenoids under the cab for wire chafing or damage causing a short to power.

1. 1

   Access the TCU

   Remove the controller cover from the rear of the tractor to access the Transmission Controller.

2. 2

   Test the Harness

   Disconnect the main connectors (e.g., C350 and C355) from the transmission controller. Measure the resistance of the low clutch solenoid circuit to check for a direct short to +12V power.

3. 3

   Repair Wiring

   If a short is found in the harness during the multimeter test, repair the damaged wire or replace the affected harness section.

4. 4

   Replace the Solenoid

   If the wiring tests good and the solenoid failed the swap test, locate the Low Clutch Solenoid on the transmission valve body. Remove the retaining hardware and extract the faulty solenoid.

5. 5

   Install New Parts

   Lubricate the new O-ring with clean transmission fluid, install it on the new solenoid valve, and secure the solenoid into the valve body.

6. 6

   Recalibrate

   Re-run the transmission calibration procedure. You may need to perform the calibration several times to allow the controller to learn the new values and obtain acceptable shift quality. Record the final calibration values for future reference.