New Holland UCM 4083 – UCM: Ground Drive: Solenoids Return Open Circuit

The controller has detected an open circuit (a break in the electrical path) on the common return line for the ground drive/forward pump control valve solenoids.

• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• L218
• L220
• 200 Series

1. 1

   Inspect the wiring harness leading to the ground drive / forward pump control valves for any visible breaks, chafing, or disconnected connectors.

2. 2

   Test the return circuit (ground/common return line) of the directional solenoids for continuity back to the UCM.

3. 3

   Check the resistance of the forward pump control valve solenoids to ensure they do not have an internal open circuit.

1. 1

   Turn off the machine and engage the battery disconnect switch (or disconnect the negative battery cable) to ensure safety before working on the electrical system.

2. 2

   Locate the forward pump control valve solenoids on the hydraulic drive pump.

3. 3

   If the diagnostic checks reveal a broken wire or damaged connector on the return circuit, repair or replace the affected section of the wiring harness.

4. 4

   If the wiring harness tests good but the solenoid has an internal open circuit, replace the faulty ground drive solenoid.

5. 5

   Reconnect the battery, power on the machine, and clear the UCM fault codes to verify the repair was successful.