Case IH 5009 – Tractor Control Unit (TCU): Rear PTO solenoid open circuit or shorted to ground or AD12vs2 voltage is low.

The Tractor Control Unit (TCU) has detected a voltage irregularity—specifically a short to ground, an open circuit, or a low voltage supply (AD12vs2)—on the circuit that controls the Rear Power Take-Off (PTO) engagement solenoid.

• Magnum
• Steiger T4B
• Case IH Magnum Series (235, 240, 245, 250, 260, 280, 290, 310, 315, 340, 370)

1. 1

   Inspect the wiring harness between the Tractor Control Unit (TCU) and the Rear PTO valve solenoid for physical damage, chafing, or loose connections.

2. 2

   Use a multimeter to check the PTO solenoid circuit for continuity to ground to isolate whether the short is in the harness or the solenoid itself.

3. 3

   Verify the AD12vs2 voltage supply by checking the fuses and relays associated with the PTO control circuit to ensure the voltage drop isn't caused by a blown fuse or failing relay.

1. 1

   Power down the tractor, remove the key, and disconnect the battery

   to prevent electrical spikes.

2. 2

   Locate the Rear PTO solenoid valve

   on the rear transmission/hydraulic valve block.

3. 3

   Disconnect the electrical connector from the PTO solenoid.

4. 4

   Test the solenoid coil's resistance with a multimeter.

   If it reads as an open circuit or is shorted directly to its casing (ground), the solenoid coil has failed.

5. 5

   Remove the retaining nut at the end of the solenoid stem and slide the old coil off.

   If the internal valve cartridge is also damaged or stuck, unthread the entire solenoid valve assembly.

6. 6

   Install the replacement PTO solenoid or coil.

7. 7

   Reconnect the wiring harness securely.

8. 8

   Reconnect the battery and power up the tractor.

9. 9

   Clear the stored fault codes from the TCU via the cab monitor.

10. 10

    Engage the Rear PTO switch to verify proper operation

    and ensure code 5009 does not return.