New Holland UCM 4082 – UCM: Ground Drive: Pumps Forward Solenoid(s) Short to Ground

The control module has detected that the electrical circuit supplying voltage to the forward directional control solenoid(s) on the hydrostatic ground drive pump has shorted to the chassis ground. When this occurs, the machine will typically be unable to drive forward, and the system may disable the ground drive entirely for safety.

• L213
• L215
• L218
• L220
• L223
• L225
• L230
• C227
• C232
• C238
• SR130
• SR160
• SR175

1. 1

   Inspect the wiring harness from the UCM to the hydrostatic drive pump for rubbed, melted, or pinched insulation causing a short to ground

2. 2

   Test the solenoid coil by measuring resistance across the pins; near zero ohms indicates an internal short

3. 3

   Check the cab fuse panel for a blown ground drive/pump fuse (e.g., 4-Amp Mini Pink fuse at position B3/B4)

4. 4

   Inspect the UCM harness connectors and the solenoid connector for water ingress, corrosion, or bent pins bridging the power circuit to ground

1. 1

   Park and secure machine

   Park the machine on a level surface, lower the loader arms completely (or engage the mechanical boom locks if they must be raised), set the parking brake, and turn off the engine.

2. 2

   Disconnect battery

   Disconnect the negative battery cable to prevent electrical sparks or further module damage.

3. 3

   Access hydrostatic pumps

   Unbolt and tilt the ROPS/cab forward and lock it into place to gain access to the hydrostatic drive pumps located under the operator's seat area.

4. 4

   Locate solenoid

   Locate the forward drive solenoid on the primary hydrostatic pump.

5. 5

   Disconnect harness

   Disconnect the wiring harness from the solenoid.

6. 6

   Repair or replace wiring

   If the wiring is shorted: Repair the damaged section of the harness using solder and marine-grade heat shrink tubing, or replace that section of the harness. Secure the harness with zip ties away from moving parts and sharp frame edges.

7. 7

   Replace solenoid coil

   If the solenoid is internally shorted: Remove the retaining nut holding the solenoid coil to the valve cartridge stem. Slide the old coil off, slide the new replacement coil on, and torque the retaining nut to OEM specifications.

8. 8

   Replace fuse

   Locate the fuse panel and replace the blown "Pump Forward" fuse (typically a 4A mini fuse).

9. 9

   Reconnect harness

   Reconnect the solenoid wiring harness.

10. 10

    Test machine

    Lower and secure the cab, reconnect the negative battery cable, and start the machine. Test the forward ground drive to verify the code is cleared and operation is restored.