Case IH 519074-05 - UCM – UCM: Rear hitch link enable solenoid current low

The control module is detecting less electrical current than expected on the circuit that powers the rear hitch enable solenoid. This condition typically prevents the rear 3-point hitch from raising, lowering, or responding to draft commands because the safety/enable valve cannot open.

• MAGNUM AFS Connect
• Magnum 180
• Magnum 200
• Magnum 240
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380
• Magnum 400
• Optum AFS Connect
• Steiger AFS Connect

1. 1

   Visually inspect the wiring harness leading to the rear hitch control valve block solenoids for physical damage, rodent chewing, or chafing.

2. 2

   Disconnect the plug at the rear hitch link enable solenoid and check for water ingress, dirt, or pushed-out/corroded pins.

3. 3

   Perform a coil resistance test using a multimeter across the two pins of the solenoid coil (an 'OL' or infinitely high reading indicates a broken internal coil).

4. 4

   Check the continuity of the wiring harness from the solenoid connector back to the UCM interface if the coil tests good.

5. 5

   With the tractor running and the rear hitch switch commanded, check for voltage at the connector to ensure the UCM is sending the signal.

1. 1

   Safety First

   Park the tractor on a level surface, lower the rear hitch completely to the ground to relieve hydraulic pressure, turn off the engine, and remove the key.

2. 2

   Clean the Area

   Thoroughly clean the area around the rear hitch control valve block to prevent dirt from entering the hydraulic system.

3. 3

   Disconnect Wiring

   Unplug the electrical connector from the failed enable solenoid.

4. 4

   Remove the Solenoid

   Depending on the specific valve block revision, either remove the retaining nut at the end of the solenoid stem to slide the electromagnetic coil off the valve cartridge, or unthread the entire solenoid cartridge valve from the block using a wrench.

5. 5

   Install the New Part

   Slide the new coil onto the stem and tighten the retaining nut (or thread the new cartridge into the block and torque to OEM specifications).

6. 6

   Reconnect and Clear

   Plug the electrical connector back in. Turn on the tractor and use the AFS Pro display (or the Case IH EST diagnostic tool) to clear the inactive 519074-05 fault code.

7. 7

   Test Operation

   Cycle the rear hitch up and down using the armrest controls to verify proper operation.