Case IH 737-00 - DEC – Transmission Control Unit (TCU) / Transmission Controller: Transmission C4 clutch solenoid maximum calibration current limit exceeded

During the automated transmission calibration routine, the electrical current drawn by the C4 clutch solenoid surpassed the maximum threshold allowed by the system software. This typically points to a short circuit in the wiring harness, a failing solenoid coil drawing excessive amperage, or a damaged connector.

• MAGNUM AFS Connect
• Case IH Maxxum series (5120, 5130, 5140, 5150)
• Case IH Farmlift telescopic handlers (633, 636, 737, 742, 935)
• Case IH Optum
• Case IH Magnum

1. 1

   Park the machine on firm ground, apply the parking brake, and shut down the engine before testing electrical components.

2. 2

   Inspect the wiring harness and the C4 clutch solenoid electrical connector (specifically noted as connector X-041 in some models) for physical damage, corrosion, or melted wires.

3. 3

   Use a multimeter to measure the voltage and current at the C4 clutch solenoid to confirm if it is shorted to ground or shorted to a 12-volt power source.

4. 4

   Check related transmission sensors (such as the transmission temperature sensor and wheel speed sensors), as faulty readings from these can interrupt or skew the calibration process.

1. 1

   Ensure the machine is safely parked, powered off, and the battery is disconnected if required by standard safety procedures.

   Safety first.

2. 2

   Locate the transmission control block where the C4 clutch solenoid valve is housed.

   Identify the location of the C4 clutch solenoid valve.

3. 3

   Disconnect the electrical connector from the C4 clutch solenoid.

   Prepare for removal.

4. 4

   Remove the attaching screws from the passage plate. Remove the passage plate and gasket to access the solenoid valve.

   Access the solenoid valve.

5. 5

   Replace the faulty C4 clutch solenoid valve. If the electrical connector or terminals are damaged or burnt, splice in the replacement connector parts.

   Install the new solenoid valve and repair wiring if necessary.

6. 6

   Reassemble the passage plate with a new gasket and reconnect the wiring harness.

   Complete the physical reassembly.

7. 7

   Perform the transmission calibration procedure.

   Note: The clutch calibration procedure must be successfully completed before fill-time calibration can occur.