Massey Ferguson 05.02.31 – Transmission Control Unit (TCU) / TRANS / TRANS1: Issue With Signal From 4wd Button On Side Pillar Dyna VT

The system has detected an irregular, missing, or out-of-range electrical signal coming from the 4-Wheel Drive (4WD) engagement button located on the right-hand side pillar control panel inside the cab.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 6614
• 6615
• 6616
• 8727
• 8730

1. 1

   Inspect the 4WD button on the right-hand side pillar for physical damage, sticking, or debris preventing it from making proper contact.

2. 2

   Check the wiring harness leading from the side pillar control panel down to the transmission control unit for chafed wires, pinched harnesses, or loose connections.

3. 3

   Disconnect the plug at the back of the side pillar keyboard/switch and inspect the pins for corrosion or moisture. Clean with contact cleaner if necessary.

4. 4

   Using a multimeter, verify the signal voltage from the switch when pressed. If the switch does not change state (open/closed) when pressed, the switch or the membrane panel has failed internally.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery terminal to prevent electrical shorts during replacement.

2. 2

   Access the Panel

   Locate the right-hand side pillar control module in the cab. Carefully pry off the trim or remove the retaining screws securing the switch panel to the pillar.

3. 3

   Disconnect Harness

   Gently pull the panel forward to access the rear. Disconnect the multi-pin wiring harness connector(s) from the back of the switch unit.

4. 4

   Remove the Switch/Keyboard

   Depending on the exact model year, the 4WD button may be an individual push-fit switch or integrated into a single "Keyboard Side Console" membrane panel. Unclip the individual switch or unbolt the entire keyboard unit from the pillar housing.

5. 5

   Install the New Part

   Seat the new switch or keyboard panel into the housing until it clicks into place or secure it with the retaining screws.

6. 6

   Reconnect

   Plug the wiring harness back into the new unit, ensuring the locking tab engages.

7. 7

   Reassembly

   Push the side pillar panel back into its mounting position and secure the trim.

8. 8

   Test

   Reconnect the battery, start the tractor, and test the 4WD engagement. Verify that the 05.02.31 fault code has moved to "inactive" or cleared from the dash display.