Case IH 4402 – UCM (Universal Control Module) or IC (Instrument Cluster): Park Brake (Mechanical Machines) Shorted To Power

The UCM or Instrument Cluster has detected a "Short to Power" in the electrical circuit that controls the Park Brake Solenoid. The controller is seeing 12V power on a circuit where it shouldn't be, causing the machine to lock the park brake on as a safety precaution.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR series
• SV series
• TR series
• TV series

1. 1

   Inspect the wiring harness leading to the park brake solenoid on the hydraulic control valve for chafed wire insulation, pinched wires, or melted loom.

2. 2

   Disconnect the park brake solenoid and check the pins inside the connector for corrosion, water intrusion, or bent pins.

3. 3

   With the key ON and the solenoid disconnected, use a multimeter to probe the harness-side connector for 12V on the ground/control circuit when the park brake is commanded ON.

4. 4

   Measure the resistance (Ohms) across the pins of the park brake solenoid itself to check for an internal short (reading near 0 ohms).

5. 5

   Check the Park Brake Pressure Switch for failure or hydraulic pressure issues in the park brake valve.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent electrical damage during the repair.

2. 2

   Harness Repair

   If your multimeter testing isolated the short to the wiring harness, trace the wire back from the solenoid to the UCM. Cut out the damaged wire, splice in a new section using weather-sealed crimp connectors, and wrap it in protective conduit.

3. 3

   Solenoid Replacement

   Locate the park brake solenoid on the hydraulic valve block and clean the area. Remove the retaining nut holding the solenoid coil to the valve stem and slide the old solenoid coil off (if the valve cartridge itself is damaged or leaking, unthread the cartridge and replace the entire assembly). Slide the new solenoid coil onto the stem and tighten the retaining nut to the manufacturer's torque spec.

4. 4

   Reassembly and Testing

   Plug the electrical connector back into the solenoid and reconnect the battery.

5. 5

   Clear Codes

   Turn the key ON and use an Electronic Service Tool (EST) or the machine's diagnostic menu to clear the inactive 4402 fault code.

6. 6

   Operational Test

   Start the machine. Cycle the park brake switch and move the control levers to verify that the "P" icon on the instrument cluster turns on and off appropriately and that the machine can drive without the brakes dragging.