Case IH 159 – TMF (Tractor Multi-Function) or CCH (Cab Controller / Central Controller): PTO remote fender switch is stuck ON

The controller is receiving a continuous "ON" signal from the exterior rear fender PTO button. This means the switch is either physically jammed in the depressed position (often due to dirt or mechanical failure) or there is a short-to-12V in the switch's internal contacts or its wiring harness.

• Magnum
• MX Magnum
• TG Series
• Steiger
• Puma
• Maxxum
• Farmall
• Optum
• MXM series
• T6000
• T7000
• T8
• T9
• TM
• TSA series

1. 1

   Inspect the rear fender PTO switch for packed mud, debris, or physical damage that might be physically holding the button down.

2. 2

   Unplug the electrical connector at the back of the fender switch and turn the key ON. If the fault code changes from 159 (Stuck ON) to 158 (Open Circuit), the wiring is fine and the switch itself is internally shorted/failed.

3. 3

   Use a multimeter to test the disconnected switch. It should only have continuity across the pins when the button is actively pressed. If it has constant continuity, it is defective.

4. 4

   If disconnecting the switch does not clear the 'Stuck ON' code, inspect the wiring harness running from the fender to the TMF/CCH controller for a short-to-power (12V).

1. 1

   Turn off the tractor and disconnect the battery to prevent electrical surges.

   Turn off the tractor and disconnect the battery to prevent electrical surges.

2. 2

   Locate the faulty PTO remote switch on the rear fender command pod.

   Locate the faulty PTO remote switch on the rear fender command pod.

3. 3

   Reach behind the fender panel (or remove the retaining screws for the pod) and disconnect the 4-pin electrical harness from the switch.

   Reach behind the fender panel (or remove the retaining screws for the pod) and disconnect the 4-pin electrical harness from the switch.

4. 4

   Unscrew the heavy-duty threaded retaining collar/nut holding the switch to the fender housing and push the old switch out.

   Unscrew the heavy-duty threaded retaining collar/nut holding the switch to the fender housing and push the old switch out.

5. 5

   Insert the new OEM switch into the housing and securely tighten the retaining collar.

   Insert the new OEM switch into the housing and securely tighten the retaining collar.

6. 6

   Apply dielectric grease to the electrical connector to prevent moisture ingress, then plug the harness back into the new switch.

   Apply dielectric grease to the electrical connector to prevent moisture ingress, then plug the harness back into the new switch.

7. 7

   Reconnect the battery and turn the ignition ON.

   Reconnect the battery and turn the ignition ON.

8. 8

   Clear the stored fault codes from the tractor's diagnostic menu.

   Clear the stored fault codes from the tractor's diagnostic menu.

9. 9

   Test the PTO engagement and disengagement from both the in-cab controls and the new fender switch to verify the repair.

   Test the PTO engagement and disengagement from both the in-cab controls and the new fender switch to verify the repair.