Case IH 5005 – CCM (Central Control Unit) / Transmission Control Module: Rear PTO brake switch – open circuit

The control module is not detecting continuity or the expected voltage return from the rear PTO brake switch circuit. The system registers an open circuit, which is typically caused by a disconnected plug, a severed wire in the harness, or an internal failure of the switch itself.

• Puma/Mid Range Magnum
• Maxxum
• VESTRUM CVX
• Case IH Puma series
• Case IH Maxxum series
• Case IH Magnum series
• Case IH Farmall series
• Case IH Steiger / STX series
• Case IH Axial-Flow Combines

1. 1

   Locate the Rear PTO brake switch and inspect its electrical connector (often designated in wiring diagrams as connector C118, X067, or X080 depending on your specific model).

2. 2

   Visually inspect the wiring harness for severed wires, chafing, or pulled pins that would cause an open circuit.

3. 3

   Disconnect the switch and use a multimeter to test the switch for continuity. If the switch reads completely open regardless of its state, the switch has failed internally.

4. 4

   Check the PTO supply fuses to ensure a blown fuse isn't cutting power to the circuit.

5. 5

   Test the harness side of the connector for proper voltage and ground to rule out a broken wire deeper in the chassis harness.

1. 1

   Turn off the tractor, remove the key, and disconnect the battery ground cable for safety.

2. 2

   Locate the Rear PTO brake switch.

3. 3

   Disconnect the electrical connector from the switch.

4. 4

   If the diagnostic checks revealed a broken wire in the harness, splice and repair the wire using weather-sealed heat shrink connectors.

5. 5

   If the switch itself failed the continuity test, unthread or unbolt the faulty switch from its mounting location.

6. 6

   Install the new Rear PTO brake switch and secure it.

7. 7

   Reconnect the electrical harness, ensuring the locking tab clicks into place to prevent future open-circuit vibrations.

8. 8

   Reconnect the battery.

9. 9

   Turn the ignition on and access the tractor's diagnostic menu to clear the stored fault codes.

   On many models, this is done by depressing and holding the navigation 'up' or 'down' keys to enter the 'Live' error code mode.

10. 10

    Start the machine and cycle the Rear PTO to verify that the brake engages/disengages properly and that code 5005 does not return.