New Holland UCM 5602 – UCM: Aux Control Function: Loader Auxiliary Solenoid(s) Short to Ground

The control module has detected that the electrical circuit supplying the directional solenoid for the loader's auxiliary hydraulics has shorted to ground.

• L213
• L218
• L220
• L223
• L230
• C227
• C232
• C238
• SR130
• SR150
• SR175
• SV185
• SR200
• SR220
• SR250
• SV300
• TR270
• TR320
• TV380

1. 1

   Inspect the loader auxiliary solenoid harness (e.g., harness W29) and connectors for chafing, pinched wires, or exposed copper that could be grounding out against the machine's chassis.

2. 2

   Disconnect the auxiliary hydraulic solenoid and check the wiring harness for continuity to ground to isolate whether the short is in the harness or the solenoid itself.

3. 3

   Test the loader auxiliary solenoid for an internal short to ground using a multimeter.

4. 4

   Check the UCM connectors and pins for corrosion or damage.

1. 1

   Turn off the machine and engage the battery disconnect switch (or disconnect the negative battery cable) to prevent electrical damage.

2. 2

   Locate the loader control valve and the attached auxiliary directional solenoids.

3. 3

   If the diagnostic tests point to a wiring issue, repair or replace the damaged section of the loader auxiliary solenoid harness.

4. 4

   If the solenoid is internally shorted, remove the retaining nut/cap and slide the faulty solenoid coil off the valve stem.

5. 5

   Install the new OEM replacement solenoid and secure it.

6. 6

   Reconnect the wiring harness, ensuring the connector is fully seated and locked.

7. 7

   Reconnect the battery, turn the key on, and verify that the UCM 5602 code has cleared or moved to an inactive state.