Case IH 519074-06 - UCM – UCM: Rear hitch link enable solenoid current high

The control module has detected that the electrical current flowing through the rear hitch enable solenoid circuit exceeds the maximum allowable threshold. This almost always indicates a short circuit to ground in the wiring harness, or an internally shorted solenoid coil on the rear hitch valve block.

• MAGNUM AFS Connect
• Magnum
• Puma
• Steiger
• Optum
• Maxxum

1. 1

   Visually inspect the wiring harness leading to the hitch enable solenoid for chafing, pinched wires, or melted insulation that could cause a short to ground

2. 2

   Disconnect the solenoid and inspect the electrical connector for water ingress, corrosion, or melted pins (do the same for the UCM harness connectors)

3. 3

   Measure the resistance across the pins of the hitch enable solenoid coil using a multimeter (near zero ohms indicates an internally shorted coil)

4. 4

   With the solenoid and UCM disconnected, test the signal wire for continuity to ground to check for a harness short

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the Solenoid

   Access the rear hitch valve assembly at the rear of the tractor. Identify the specific "enable" solenoid (refer to your specific model's hydraulic schematic if there are multiple coils).

3. 3

   Remove the Faulty Component

   Disconnect the electrical pigtail from the solenoid. Remove the retaining nut at the end of the solenoid stem and slide the faulty electromagnetic coil off the valve cartridge.

4. 4

   Repair Wiring (If Applicable)

   If the diagnostic tests pointed to a harness short rather than a bad coil, locate the chafed wire, cut out the damaged section, and repair it using a weather-sealed butt connector and heat shrink tubing.

5. 5

   Install New Solenoid

   Slide the new solenoid coil onto the valve stem and secure it with the retaining nut (do not overtighten, as this can distort the cartridge).

6. 6

   Reconnect and Clear Codes

   Reconnect the electrical harness and the battery. Turn the key on and use the AFS Pro monitor (e.g., Pro 1200) or the Case IH Electronic Service Tool (EST) to navigate to the "Faults and Warnings" menu and clear the inactive fault codes.

7. 7

   Test Operation

   Start the tractor and test the rear hitch raise/lower functions to ensure the code does not return.