Case IH 5008 – Rear PTO Controller, Armrest Controller, or Tractor Control Unit (TCU) / Total Machine Fault (TMF) module: Both PTO On and Off switches are simultaneously on. One of the PTO switches is short to 12 volts

The system is receiving conflicting signals from the PTO engagement switch, detecting a short circuit to a 12-volt power source on one of the switch circuits.

• Magnum
• Steiger T4B
• Case IH Magnum series (including MX series and Series 4 models like 235–340)
• Case IH Steiger series (350–600)
• Case IH Maxxum MX series
• Case IH Puma series

1. 1

   Verify Transmission/PTO configuration via the controller configuration and calibration menu to ensure a misconfiguration is not triggering the code.

2. 2

   Check PTO Switch Power (ON Position): Verify there is 12V at the armrest controller connector C054 pin 4, connector C054 pin 5, and at the tractor control unit (TCU) connector C065 pin 29.

3. 3

   Check PTO Switch Power (OFF Position): Verify there is 12V at the armrest controller connector C054 pin 6 and at the tractor control unit (TCU) connector C066 pin 10.

4. 4

   Update the software for the armrest controller if the PTO switch power is not as expected during the pinout tests.

1. 1

   Disconnect battery

   Disconnect the tractor's battery to ensure safety while working on the electrical system.

2. 2

   Access PTO switch

   Disassemble the armrest console to access the rear of the PTO switch.

3. 3

   Disconnect wiring harness

   Disconnect the wiring harness from the faulty PTO switch.

4. 4

   Remove faulty switch

   Remove the faulty PTO switch from the armrest console mounting.

5. 5

   Install new switch

   Install the new replacement PTO switch into the armrest console and reconnect the wiring harness.

6. 6

   Reassemble and reconnect

   Reassemble the armrest console and reconnect the battery.

7. 7

   Clear fault codes

   Clear all fault codes from the system.

8. 8

   Test operation

   Test the operation of the PTO switch to ensure the fault code does not re-display and the PTO engages/disengages correctly.