Case IH 5005 - UCM – UCM or CCM: Rear PTO brake switch – open circuit

The control module is not detecting the expected electrical continuity or voltage return from the rear Power Take-Off (PTO) brake switch circuit, meaning the circuit is physically broken, unplugged, or the switch has failed internally.

• MAXXUM T4E
• Puma Series (125, 140, 165, 180, 195, 210, 225)
• Maxxum Series (110, 115, 120, 125, 130, 140)
• Magnum Series
• Farmall Series (115U)

1. 1

   Check the connector at the Rear PTO brake switch (C118, X067, or S-011) to ensure it is fully seated and no pins have been pushed back out of the housing.

2. 2

   Inspect the wiring harness for physical damage, rodent damage, or chafing against the chassis. Pay special attention to the PTO Brake Signal wire (2120 or 2120A) and the PTO Supply wire (2050 or 2050J).

3. 3

   Use a multimeter to test the switch itself for continuity when actuated. If it reads open regardless of position, the switch has failed internally.

4. 4

   Verify that the switched 12V supply fuse for the PTO/armrest controls is not blown.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the negative battery terminal to prevent electrical shorts during repair.

2. 2

   Locate the Switch

   Locate the Rear PTO brake switch. Depending on your exact model and cab configuration, this is typically located in the right-hand armrest console or the rear fender control area.

3. 3

   Expose the Wiring

   Remove the necessary trim panels to access the switch and its wiring pigtail.

4. 4

   Repair the Harness

   If you found broken wires during your diagnostic checks, strip back the damaged section and repair it using automotive-grade butt connectors and heat-shrink tubing.

5. 5

   Replace the Switch

   If the switch failed the continuity test, unclip or unthread the faulty switch from its mounting bracket and install the new replacement.

6. 6

   Reassemble

   Plug the harness connector back into the switch, ensuring the locking tab clicks into place. Reinstall any removed trim panels.

7. 7

   Clear Codes

   Reconnect the battery, turn the ignition on, and verify that the 5005 error code has cleared from the display. Test the PTO engagement to ensure normal operation.