Massey Ferguson D156 – Dash (Instrument Panel / Instrument Cluster): Top-of-Clutch (TOC) pedal switch stuck open

The system is detecting an open circuit at the clutch pedal sensor (designated in wiring diagrams as sensor X68). Because the switch is stuck open, the tractor's electronic management system cannot accurately determine the position of the clutch pedal, which can affect transmission shifting and power shuttle operations.

• MF 8650
• MF 8680
• Interim Tier 4 (2012-2015)
• 7615
• 5613
• MF 8480
• MF 8450
• 7616
• 7618
• 5608
• 7619
• 7626
• MF 8660
• 7624
• MF 8690
• 7614
• MF 8470
• 5610
• 7620
• MF 8600
• MF 8460
• MF 8670
• 5612
• 7622
• 5611
• 5609
• MF 5600 Series
• MF 7600 Series
• MF 8400 Series
• MF 8600 Series

1. 1

   Inspect the wiring harness leading to the X68 clutch pedal sensor. Check for an open circuit on the 12V supply line at the switch connector. Look for damaged wires, corrosion, or loose pins

2. 2

   Check for incorrect mechanical adjustment of the switch or the clutch pedal itself. Ensure that when the pedal is fully released, it physically makes contact with and properly actuates the switch plunger

3. 3

   Disconnect the switch and use a multimeter to test it for continuity. If the switch reads 'open' regardless of whether the plunger is pressed or released, the switch has failed internally

4. 4

   Ensure there is no debris behind the clutch pedal preventing it from returning to its resting position

1. 1

   Locate the Sensor

   Locate the Top-of-Clutch (TOC) pedal switch (Sensor X68) mounted near the top pivot point of the clutch pedal assembly inside the cab.

2. 2

   Disconnect Power

   Turn off the tractor ignition and disconnect the electrical connector from the switch.

3. 3

   Remove the Faulty Switch

   Unbolt or unclip the switch from its mounting bracket.

4. 4

   Install the New Switch

   Mount the new OEM clutch pedal switch into the bracket.

5. 5

   Adjust the Switch

   If the mounting bracket is slotted for adjustment, adjust the position of the switch so that the clutch pedal fully depresses the switch plunger when the pedal is in its natural, unpressed (top) position.

6. 6

   Reconnect

   Plug the electrical harness back into the switch.

7. 7

   Clear Codes & Test

   Turn the ignition on, clear the fault codes from the Dash/Instrument Panel, and test the clutch pedal operation (forward/reverse shuttling) to ensure the code does not return.