Case IH 9016 - UCM – UCM: External fender switch open circuit/short to GND

The electrical circuit for the external fender switch—which allows the operator to control the rear Power Take-Off (PTO) or the electronic draft control (EDC) 3-point hitch lift from outside the cab—has either a broken connection (open circuit) or a wire that is improperly grounding out (short to ground).

• MAXXUM T4E
• VESTRUM CVX
• Case IH Maxxum Series (110, 115, 120, 125, 130, 140)
• Case IH Puma Series (130, 140, 145, 160)
• Case IH Magnum Series (235 - 340)
• Case IH Farmall Series

1. 1

   Visual Inspection: Inspect the external fender switch for physical damage, cracked housing, or water/debris ingress, as these switches are exposed to the elements.

2. 2

   Wiring Harness Check: Trace the wiring harness from the fender switch back to the UCM. Look for pinched wires, chafing against the fender chassis, or broken lines that would cause an open circuit or short to ground.

3. 3

   Connector Pin Check: Disconnect the switch and inspect the connector pins for corrosion, bent pins, or loose terminals.

4. 4

   Multimeter Testing: Use a multimeter to test the switch for proper continuity when pressed. Test the harness side for a short to ground (GND) or an open circuit.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent electrical shorts during the repair.

2. 2

   Access the Switch

   Locate the faulty external fender switch on the rear fender panel (either the PTO or the hitch raise/lower switch, depending on which is throwing the code).

3. 3

   Disconnect Harness

   Reach behind the fender panel and carefully unplug the wiring harness connector from the back of the switch.

4. 4

   Remove the Switch

   Depress the retaining tabs or remove the mounting hardware/clips securing the switch to the fender housing, and push the switch out of its mounting hole.

5. 5

   Install New Part

   Snap the new OEM fender switch into the fender panel until it is securely seated.

6. 6

   Reconnect

   Plug the wiring harness connector into the new switch, ensuring the locking tab clicks into place. (If the wiring harness itself was the issue, repair or replace the damaged wire/clip before reconnecting).

7. 7

   Test

   Reconnect the battery. Turn the key on, clear the stored UCM fault codes, and test the external fender switch to verify the PTO or hitch operates correctly without triggering the 9016 code.