New Holland UCM 4061 – UCM: Ground Drive: Solenoid Right (A) Supply Open Circuit

The control module has detected an open circuit (a loss of electrical continuity or infinite resistance) on the supply line providing power to the right-side forward ground drive pump control solenoid. Because of this open circuit, the machine will likely fail to drive forward on the right side or may be completely immobilized for safety.

• L213
• L215
• L216
• L218
• L220
• L225
• L228
• L316
• L318
• L320
• C227
• C232
• C238
• SR175
• B90B/B100B

1. 1

   Check the power distribution box for blown fuses or faulty relays related to the ground drive system (bad relays are a highly common failure point on models like the L218).

2. 2

   Visually inspect the wiring harness running from the UCM to the right ground drive pump for chafing, breaks, or pinch points.

3. 3

   Disconnect the harness at the right forward pump control solenoid (Solenoid A) and inspect the pins for corrosion, moisture, or pushed-out terminals.

4. 4

   Use a multimeter to test the continuity of the supply wire from the UCM pinout to the solenoid connector.

5. 5

   Measure the resistance across the pins of the solenoid itself. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the solenoid coil has failed internally.

1. 1

   Preparation

   Park the machine on a level surface, lower the boom (or engage the boom lock), turn off the engine, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Access the Pump

   Lift the cab or open the rear access panels as required by your specific model to access the hydrostatic drive pumps.

3. 3

   Locate the Solenoid

   Locate the right-side forward pump control valve (often a Sauer Danfoss ground drive proportional solenoid).

4. 4

   Repair the Circuit

   If the harness is damaged: Repair the broken wire using OEM-approved weatherproof splice connectors, or replace the affected harness section. If the solenoid failed the resistance test: Remove the retaining nut holding the solenoid coil to the valve stem. Slide the old coil off and install the replacement. Torque the retaining nut to OEM specifications (do not overtighten, as this can warp the valve spool).

5. 5

   Reassembly

   Reconnect the solenoid electrical connector, ensuring the locking tab clicks into place.

6. 6

   Restore Power & Calibrate

   Reconnect the negative battery cable. Turn the key on and use the Electronic Service Tool (EST) or the instrument cluster to clear the inactive fault codes. You may need to perform a 'Ground Drive Calibration' procedure via the UCM to restore self-learning parameters.