New Holland IC 4402 – IC (Instrument Cluster) / UCM (Universal Control Module): Park Brake (Mechanical Machines) - Park Brake Solenoid - Short to Power

The control module has detected an electrical short to a power source within the park brake solenoid circuit. When this occurs, the controller sees unexpected voltage on the circuit, which can prevent the park brake from engaging or disengaging properly.

• L213
• L215
• L218
• L220
• L228
• L316
• L318
• L320
• C227
• C232
• C238

1. 1

   Harness Inspection: Visually inspect the main wiring harness (specifically harness X-26) between the UCM/IC and the park brake solenoid for rubbed insulation, pinched wires, or areas where the wire might be shorting against a 12V power source.

2. 2

   Voltage Check (Short to Power Test): Turn the ignition OFF, disconnect the park brake solenoid and the corresponding connector at the UCM/IC, turn the ignition ON, and use a multimeter to probe the park brake solenoid signal wire. Voltage present indicates a short to power in the harness.

3. 3

   Solenoid Resistance Test: Measure the resistance across the pins of the park brake solenoid. A reading near zero ohms indicates the solenoid is internally shorted.

4. 4

   Plausibility Check: Check the Park Brake Pressure Switch. A shorted solenoid often triggers a secondary code (4431) because the UCM senses a disagreement between the commanded solenoid state and the actual hydraulic pressure switch reading.

1. 1

   Disconnect Power

   Turn off the machine and engage the battery quick-disconnect switch (if equipped), or disconnect the negative battery cable to prevent electrical damage during repair.

2. 2

   Access the Solenoid

   Locate the park brake solenoid block/valve assembly on the hydraulic control block.

3. 3

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed voltage on the wire when disconnected, trace the harness back to the cab to locate the short. Splice and repair the damaged wire using heat-shrink connectors, or replace the affected harness section.

4. 4

   Replace the Solenoid (If Applicable)

   If the wiring is intact but the solenoid failed the resistance test, remove the retaining nut holding the electrical coil to the cartridge valve. Slide the old coil off and install the new one. (If the cartridge valve itself is damaged, replace the entire valve assembly).

5. 5

   Reassemble and Test

   Reconnect the battery. Turn the key on, clear the stored fault codes using the instrument cluster or a diagnostic tool, and cycle the park brake button to ensure the mechanical lockouts engage and disengage properly without throwing the code.