Case IH 8007 - UCM – UCM: Front PTO solenoid - stuck on

The control module is detecting that the Front Power Take-Off (PTO) circuit is active, energized, or receiving an 'ON' command signal when the operating conditions dictate it should be off (such as when the engine is shut down).

• MAXXUM T4E
• VESTRUM CVX
• Case IH Puma 125
• Case IH Puma 140
• Case IH Puma 165
• Case IH Puma 180
• Case IH Puma 195
• Case IH Puma 210
• Case IH Puma 225
• Case IH Puma CVX
• Case IH Magnum 235-340 (Series 4)
• Case IH Magnum MX210-MX285
• Case IH Maxxum 100-140
• Case IH Steiger Series

1. 1

   Verify the physical position of the Front PTO switch in the cab to ensure it is not physically jammed in the 'ON' position or obstructed by debris.

2. 2

   Test the Front PTO cab normally open (N/O) and normally closed (N/C) switch contacts with a multimeter to ensure the switch isn't internally shorted closed.

3. 3

   Disconnect the Front PTO solenoid (connector X393 or X954) and check for voltage at the connector with the key ON and the PTO switch OFF. Voltage present indicates a short-to-power (B+) in the wiring harness.

4. 4

   Check the resistance of the Front PTO solenoid coil to ensure the internal coil is not shorted, which can trigger stuck-on or overcurrent faults.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery ground to prevent accidental short circuits during repair.

2. 2

   Address the Switch (If Faulty)

   If the diagnostic checks point to the cab switch (switch reads ON when engine is OFF), carefully pry the switch bezel from the side console/armrest, disconnect the wiring pigtail, and snap a new OEM switch into place.

3. 3

   Access the Solenoid

   If the switch and wiring are good, locate the Front PTO solenoid valve assembly at the front of the tractor near the front hitch/PTO housing.

4. 4

   Remove the Solenoid Coil

   Disconnect the electrical connector. Remove the retaining nut at the top of the solenoid stem. Slide the electromagnetic coil off the valve cartridge.

5. 5

   Inspect the Valve Cartridge

   Check the exposed valve stem for physical damage or sticking. If the internal spool is mechanically jammed open, the entire cartridge valve must be unthreaded and replaced.

6. 6

   Install New Components

   Slide the new solenoid coil over the valve stem (or thread in a new cartridge valve if replacing the whole assembly). Tighten the retaining nut to the specified torque in your model's service manual.

7. 7

   Reconnect and Clear Codes

   Reconnect the wiring harness. Reconnect the battery. Turn the key on and use the tractor's diagnostic display or the EST (Electronic Service Tool) to clear the UCM fault stack.

8. 8

   Test Operation

   Start the engine and cycle the Front PTO switch to ensure it engages and disengages properly without throwing code 8007.