Case IH 737-13 - DEC – Transmission Control Unit (TCU): Transmission C4 clutch solenoid out of calibration

The transmission controller does not have a valid calibration value for the C4 clutch solenoid valve. The system requires precise calibration of the clutch fill times and pressures to ensure smooth shifting; when the C4 clutch parameters fall out of the acceptable calibration range (or if a calibration has not been successfully completed), this code is triggered.

• MAGNUM AFS Connect
• Case IH Magnum series
• Case IH Maxxum series

1. 1

   Park the machine on firm, level ground, apply the parking brake, shut down the engine, and chock the wheels before performing any tests.

2. 2

   Verify that the transmission oil level is correct and that the transmission oil temperature sensor is functioning, as calibration cannot complete successfully if the oil is too cold or low.

3. 3

   Inspect the wiring harness leading to the transmission control valve block. Look for damaged wires or loose connections at the C4 clutch solenoid.

4. 4

   Use a multimeter to measure the resistance of the C4 clutch solenoid coil to confirm it is not internally shorted or open.

1. 1

   Prepare the Machine

   Ensure the tractor is turned off, the parking brake is engaged, and the transmission is in neutral.

2. 2

   Locate the Solenoid

   Locate the transmission control valve block on the transmission housing and identify the C4 clutch solenoid valve.

3. 3

   Disconnect Wiring

   Carefully unplug the electrical connector (Connector X-041) from the C4 clutch solenoid.

4. 4

   Replace the Solenoid (if faulty)

   If the solenoid failed the resistance test or is mechanically sticking, remove its retaining fastener and pull the C4 clutch solenoid valve out of the transmission valve block.

5. 5

   Install New Parts

   Lubricate the O-rings on the new solenoid with clean transmission fluid, insert it into the valve block, and secure it.

6. 6

   Repair Connectors (if necessary)

   If the wiring connector is damaged, splice in a new terminal connector. Reconnect the harness to the solenoid.

7. 7

   Perform Transmission Calibration

   Start the tractor, bring the transmission fluid up to normal operating temperature, and initiate the calibration via the instrument cluster or electronic service tool so the TCU can learn the new C4 clutch fill parameters.