Case IH 5371 – UCM (Universal Control Module): EHF Forward Solenoid (A) Supply STG

Indicates a circuit failure (Short to Ground or Open Circuit) on the supply line to the Forward Solenoid (A) of the Enhanced High-Flow (EHF) auxiliary hydraulic system.

• skid steer
• SR175
• SR250
• SR270
• SV300
• SV340B
• TR320
• TV380
• TV450B
• Steiger
• Puma
• Magnum
• MX/TG series

1. 1

   Inspect the wiring harness between the UCM and the EHF Forward Solenoid (A) for chafing, pinched wires, or areas where the insulation has rubbed through, causing a short to the chassis ground.

2. 2

   Disconnect the plug at the EHF Forward Solenoid (A) and check for moisture, corrosion, or bent pins that could bridge the connection to ground.

3. 3

   Measure the resistance across the pins of the EHF Forward Solenoid (A) coil using a multimeter. An abnormally low reading (near zero ohms) indicates the coil is internally shorted to ground. An infinite reading indicates an open circuit.

4. 4

   With the key on (and the solenoid disconnected), verify if the UCM is sending the correct reference/supply voltage to the connector.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent accidental shorts or UCM damage during repair.

2. 2

   Locate the Solenoid

   Locate the Enhanced High-Flow auxiliary gear pump and valve block assembly (often located near the main hydrostatic pumps). Identify the Forward Solenoid (A) / PRV cartridge.

3. 3

   Repair Wiring

   If the diagnostic checks revealed a short to ground in the harness, splice in a new section of wire or replace the damaged connector pigtail using a weather-sealed heat shrink connector.

4. 4

   Replace the Solenoid

   If the solenoid coil failed the resistance test, remove the retaining nut holding the coil to the PRV cartridge stem. Slide the old coil off and install the new one. (If the cartridge itself is mechanically stuck or leaking internally, the entire PRV cartridge may need to be unthreaded and replaced).

5. 5

   Reassemble and Test

   Reconnect the electrical harness, reconnect the battery, clear the UCM fault codes, and test the EHF auxiliary hydraulics in the forward direction to ensure the code does not return.