Case IH 63 – PTO Control Module or Instrumentation Controller / Electronic Management Unit (DEC controller): PTO speed sensor is not reading

The PTO speed sensor is failing to send the expected speed signal to the controller. When the controller does not detect this signal during PTO engagement, it logs code 63 and will often disengage the PTO for safety.

• MX Maxxum
• MX80C
• MX90C
• MX100
• MX110
• MX120
• MX135
• MX210
• MX230
• MX255
• MX285
• Maxxum 100
• Maxxum 110
• Maxxum 115
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 140
• Magnum 180
• Magnum 190
• Magnum 210
• Magnum 225
• Puma 115
• Puma 185
• Puma 180-260 CVX
• Farmall 85C
• Farmall 95C
• Farmall 95U
• Farmall 105C
• Farmall 105U
• Farmall 115U
• Optum 250
• Optum 270
• Optum 300
• C80
• C90

1. 1

   Check the resistance of the PTO speed sensor across its two pins to ensure it is within the specified range

2. 2

   Check the wiring harness and connectors (e.g., C060 to C061) from the PTO speed sensor to the controller for open or short circuits

3. 3

   Verify good continuity to a clean ground and check for a 5 VDC reference power supply at the sensor connector with the key in the 'RUN' position

4. 4

   Ensure the sensor is positioned correctly relative to the tone ring and the gap is not too large

1. 1

   Safety First

   Power off the machine, remove the key, and ensure all safety locks are in place before servicing the rear PTO housing.

2. 2

   Locate and Remove

   Locate the PTO speed sensor on the rear drivetrain/PTO housing. Unplug the electrical wiring harness connector from the sensor.

3. 3

   Extract Sensor

   Unscrew and remove the faulty sensor from the housing.

4. 4

   Install New Sensor

   Thread the new sensor into the housing. You must set the correct gap between the sensor tip and the internal tone ring (often around 1/8", but refer to your specific model's manual) so it can read the teeth without making physical contact.

5. 5

   Reassemble

   Tighten the sensor carefully (do not overtighten) and reconnect the electrical harness.

6. 6

   Calibration/Syncing

   Sync/configure the PTO and engine RPMs. This often involves installing a configuration jumper, starting the engine and setting RPMs to 1000, and moving the PTO switch to the RUN position so the controller can calculate engine versus PTO speed.