Massey Ferguson D135 – Instrument Panel: Electrical signal too high (Power Control lever)

The control module is receiving a voltage reading from the forward/reverse shuttle lever's position sensor that exceeds the normal operating parameters. This is typically caused by a short circuit to +12V on the signal line, or an open circuit on the potentiometer's ground line.

• 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 5400 Series
• MF 6400 Series
• MF 7400 Series
• MF 7600 Series
• MF 8400 Series
• MF 8600 Series

1. 1

   Inspect the wiring harness connecting the Power Control lever (X56) to the Instrument Panel for chafed wires near the steering column tilt mechanism.

2. 2

   Use a multimeter to check the signal wire between the lever and the dash for a short circuit to +12V.

3. 3

   Verify continuity on the potentiometer's ground circuit, as an open ground will cause the signal voltage to default high.

4. 4

   Disconnect the lever and inspect the connector pins for corrosion, moisture, or pushed-out terminals.

5. 5

   Back-probe the sensor and perform a potentiometer sweep test while moving the lever through Forward, Neutral, and Reverse. If voltage spikes or stays stuck high, the internal potentiometer has failed.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical damage or accidental shorting during disassembly.

2. 2

   Remove Trim

   Remove the steering column cowlings and lower dash trim panels to access the base of the left-hand Power Control lever.

3. 3

   Disconnect Harness

   Unplug the electrical harness connector from the X56 Power Control lever.

4. 4

   Dismount the Lever

   Remove the mounting bolts/screws securing the Power Control lever assembly to the steering column bracket.

5. 5

   Install New Part

   Mount the new Power Control lever assembly into position and secure the hardware.

6. 6

   Reconnect

   Plug the electrical harness back into the new lever, ensuring the connector clicks securely into place.

7. 7

   Reassemble

   Reinstall the steering column cowlings and dash trim panels.

8. 8

   Clear Codes & Test

   Reconnect the battery. Turn the ignition on, clear the stored D135 fault code from the Dash Control Center, and test the forward/reverse shuttle operation to confirm the repair. (Note: Some models may require a brief shuttle calibration via the dash menu after replacing the lever).