Massey Ferguson D143 – Instrument Panel (Dash) module (X55) / Transmission Controller: Issue With Signal Voltage From Clutch Pedal Sensor, High Voltage

The control module is receiving an abnormally high voltage signal from the clutch pedal sensor (X68), indicating the sensor has failed internally or the wiring harness has shorted to a 12V power source. This can cause the tractor to cut drive after clutch use, behave inconsistently when selecting direction, or trigger harsh/jumpy clutch engagements.

• 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
• 5400 Series
• 6200 Series
• 6400 Series
• 6600 Series
• 7400 Series
• 7600 Series
• 7700 Series
• 7614-7626
• 7714-7726
• 8200 Series
• 8400 Series
• 8600 Series
• 8650-8690
• 5700SL Series
• 5710SL
• 5711SL
• 5712SL
• 5713SL
• 6100 Series
• 4700 Series

1. 1

   Inspect the wiring harness leading to the clutch pedal sensor for rubbed insulation, pinched wires, or areas where the signal wire might be shorting to a 12V power wire.

2. 2

   Disconnect the sensor and inspect the connector pins for corrosion, moisture, or damage.

3. 3

   Test the sensor using a multimeter to check the resistance/voltage sweep as the pedal is depressed. If the voltage is stuck at 12V or the resistance is out of limits/open, the sensor is internally faulty.

4. 4

   Attempt a clutch pedal calibration via the dash/diagnostic tool if the sensor tests fine, though a hard high voltage code usually points to electrical failure.

1. 1

   Access the Pedal Box

   Locate the clutch pedal sensor (BOC switch/potentiometer) situated at the base of the clutch pedal assembly inside the cab.

2. 2

   Disconnect Battery

   Disconnect the negative battery terminal to prevent electrical spikes during replacement.

3. 3

   Remove the Sensor

   Unplug the electrical connector from the sensor. Remove the mounting screws/hardware securing the sensor to the pedal linkage.

4. 4

   Install the New Sensor

   Mount the replacement sensor in the exact orientation as the old one. Secure the mounting hardware.

5. 5

   Reconnect

   Plug the electrical harness back into the sensor and reconnect the battery.

6. 6

   Clear Codes & Calibrate

   Turn the ignition on and clear the D143 fault code from the instrument panel. It is highly recommended to perform a clutch pedal calibration procedure to ensure the transmission controller learns the new sensor's exact engagement points.