Massey Ferguson T5151 – Transmission Controller: Issue With Signal From Diff Lock Button On Side Pillar Dyna VT

The control module is receiving an incorrect, missing, or out-of-range electrical signal from the differential lock switch (component X136).

• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 7615
• 7620
• 7616
• 7618
• 7619
• 7626
• 7624
• 8670
• 8690

1. 1

   Use a multimeter to test the differential lock switch (X136) on the right-hand side pillar for proper electrical continuity when engaged and disengaged

2. 2

   Inspect the wiring harness and electrical connectors running between the side pillar switch and the transmission controller for corrosion, moisture ingress, or broken wires

3. 3

   Ensure the differential lock button is not physically stuck, jammed by debris, or damaged

1. 1

   Power down and disconnect battery

   Power down the tractor and disconnect the battery to prevent electrical shorts.

2. 2

   Remove side pillar trim

   Carefully remove or unclip the right-hand side pillar trim/console panel to access the rear of the switch block.

3. 3

   Disconnect switch harness

   Disconnect the electrical spade connector/harness from the back of the differential lock switch.

4. 4

   Replace faulty switch

   Remove the faulty switch (usually pops out of the panel housing) and snap the new switch into place.

5. 5

   Apply dielectric grease and reconnect

   Apply a small amount of dielectric grease to the terminals to prevent future corrosion, then reconnect the wiring harness.

6. 6

   Reinstall trim panel

   Reinstall the side pillar trim panel.

7. 7

   Reconnect battery and test

   Reconnect the battery, clear the fault codes from the transmission controller, and test the differential lock engagement in a safe environment.