Case IH 519070-02 - UCM – UCM: Rear hitch exterior top link switch left - high voltage

The control module has detected that the signal voltage from the left rear fender's exterior top link switch is above the normal operating range. This condition typically points to an open circuit, a short to a 12V power source, or an internal failure of the switch itself.

• MAGNUM AFS Connect
• Magnum 180 AFS Connect
• Magnum 220 AFS Connect
• Magnum 250 AFS Connect
• Magnum 310 AFS Connect
• Magnum 340 AFS Connect
• Magnum 380 AFS Connect
• Magnum 400 AFS Connect

1. 1

   Inspect the left rear fender exterior top link switch and its electrical connector (X-403) for physical damage, dirt, corrosion, or moisture intrusion.

2. 2

   Trace the wiring harness from the switch back to the UCM. Look for chafing, cuts, or pinched wires. Use a multimeter to test the circuit for a short to power or an open ground.

3. 3

   Disconnect the switch and use a multimeter to test for proper continuity across the switch terminals when the buttons are pressed and released.

4. 4

   Turn the key on and probe the harness-side connector to verify it is receiving the correct reference voltage and ground from the UCM.

1. 1

   Prepare tractor

   Park the tractor on a level surface, lower the rear hitch to the ground, and turn off the engine.

2. 2

   Disconnect power

   Disconnect the battery or turn off the master disconnect switch to prevent electrical shorts.

3. 3

   Locate switch

   Locate the left exterior top link switch on the rear fender.

4. 4

   Disconnect connector

   Reach behind the fender panel and disconnect the 3-pin electrical connector (X-403) from the back of the switch.

5. 5

   Remove switch

   Depress the retaining tabs or remove the mounting hardware securing the switch to the fender housing, and push the switch out.

6. 6

   Install new switch

   Snap the new replacement switch into the fender housing.

7. 7

   Reconnect connector

   Reconnect the electrical connector, ensuring the locking tab clicks and is fully seated.

8. 8

   Reconnect power

   Reconnect the battery/master switch.

9. 9

   Clear fault code

   Clear the fault code using the tractor's AFS Pro monitor or an electronic service tool.

10. 10

    Test operation

    Test the rear hitch operation using the newly installed exterior fender switch to verify the repair.