New Holland UCM 5371 – UCM: Enhanced High-Flow Auxiliary Option: Forward Solenoid (A) Supply Open Circuit

The control module has detected a break in the electrical circuit (open circuit) supplying power to the forward directional solenoid (A) of the Enhanced High-Flow (EHF) proportional relief valve (PRV) on the hydrostatic pump assembly.

• L218
• L220
• L228
• L313
• L315
• L318
• L320
• L323
• L325
• L330
• C327
• C332
• C338
• SR130
• SR150
• SR175
• SV185
• SR200
• SR220
• SR250
• SV250
• SV300
• TR270
• TR320
• TV380

1. 1

   Visually inspect the wiring harness leading to Forward Solenoid (A) on the hydrostatic pump assembly for chafing, cuts, or broken wires.

2. 2

   Disconnect the Deutsch DT series electrical connector at the solenoid and check for pushed-back pins, corrosion, or moisture intrusion.

3. 3

   Turn the key ON and verify the supply voltage at the harness connector (system operates on a 14V standard).

4. 4

   Measure the resistance across the pins of the solenoid coil itself; an 'OL' (Open Loop) or infinite reading indicates internal coil failure.

5. 5

   Check the continuity of the supply wire from the UCM to the solenoid connector to rule out a broken wire in the main harness.

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Access the Pump

   Tilt the cab or open the rear access panels as required by your specific model to access the hydrostatic pump assembly.

3. 3

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a broken wire or damaged Deutsch DT connector, splice in a new section of wire or replace the connector pigtail using proper weather-sealed heat shrink connectors.

4. 4

   Replace Solenoid (If Applicable)

   If the solenoid coil tested open: Clean the area around the EHF PRV to prevent dirt from entering the hydraulic system. Unplug the Deutsch DT connector. Unscrew the retaining nut holding the solenoid coil to the valve stem and slide the old coil off (or remove the entire PRV cartridge if it is a one-piece unit). Install the new solenoid/valve, torque to OEM specifications, and plug in the connector.

5. 5

   Reassembly and Testing

   Reconnect the battery. Use a diagnostic tool or CAN-bus DTC eraser to clear the UCM 5371 code. Start the machine and engage the Enhanced High-Flow auxiliary hydraulics in the forward direction to verify the repair.