New Holland IC 4401 – IC (Instrument Cluster) / UCM (Universal Control Module): Park Brake (Mechanical Machines) - Park Brake Solenoid - Open Circuit

The control system has detected a break in the electrical circuit (open circuit) that supplies power to the park brake solenoid, preventing the system from electronically releasing or engaging the parking brake.

• L213
• L215
• L218
• L220
• L223
• L225
• L230
• C227
• C232
• C238

1. 1

   Visually inspect the main wiring harness under the cab/seat and fenders for abrasions, severed wires, or disconnected plugs.

2. 2

   Perform a harness continuity test between the supply pin on the module connector and the solenoid connector.

3. 3

   Test for battery voltage at the solenoid connector when the park brake release is commanded by the operator.

4. 4

   Check the internal resistance of the Park Brake Solenoid (infinite resistance/OL indicates an internal open circuit and a defective solenoid).

5. 5

   Verify seat switch and seat belt switch functionality, as an open circuit in the safety interlock switches can interrupt power to the park brake release circuit.

1. 1

   Secure the Machine

   Ensure the boom is safely lowered or locked in the air, and the machine is turned off.

2. 2

   Repair Wiring

   If the continuity test revealed an open wire in the harness (often found under the seat or near the fenders), splice and repair the damaged wire using weather-resistant connectors.

3. 3

   Replace Solenoid

   If the harness is intact but the solenoid failed the resistance test (internal open circuit) or is mechanically seized, remove the defective park brake solenoid from the hydraulic block.

4. 4

   Install New Solenoid

   Install the replacement solenoid, ensuring the O-rings are properly seated to prevent hydraulic leaks.

5. 5

   Reconnect and Clear

   Reconnect all electrical harnesses. Turn the key on, use the Electronic Service Tool (EST) or the instrument cluster to clear the inactive IC 4401 fault code, and test the park brake engagement/disengagement.