Massey Ferguson 3.X.95 – TECU: High Voltage On Auxiliary Valve Switch 6 (TECU)

The controller is receiving a voltage signal from the 6th auxiliary valve switch that exceeds normal operating parameters, indicating a short circuit to a 12V power source on the signal wire, or an internal short within the switch potentiometer itself.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714
• 7715
• 7715S
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726

1. 1

   Trace the wiring harness from the armrest console (Auxiliary Valve Switch 6) down to the TECU. Look for chafed wire insulation, pinched wires in the armrest pivot points, or exposed copper that could be shorting the signal wire to a 12V power wire.

2. 2

   Disconnect the plug at the fingertip control module/switch and the TECU. Inspect for water ingress, corrosion, or bent pins that could bridge the power and signal terminals.

3. 3

   With the switch disconnected, turn the key ON and measure the voltage on the signal wire of the harness. If it reads 12V, the short is in the wiring harness. If it reads 0V (or a standard 5V reference), the short is likely internal to the switch itself.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the negative battery terminal to prevent electrical spikes.

2. 2

   Access the Switch

   Remove the retaining screws on the armrest console to access the underside of the fingertip control module or joystick where Switch 6 is housed.

3. 3

   Disconnect and Isolate

   Unplug the electrical connector for the affected switch.

4. 4

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a short to 12V in the harness, splice and repair the damaged section of the wire using heat-shrink butt connectors, then re-loom the harness.

5. 5

   Replace the Switch (If Applicable)

   If the harness tested fine, the switch has failed internally. Remove the retaining clips/screws holding the auxiliary switch into the armrest bezel and install the replacement unit.

6. 6

   Reassemble and Power Up

   Reconnect the switch, reassemble the armrest console, and reconnect the battery.

7. 7

   Calibration

   After replacing an auxiliary valve switch, you must perform a valve calibration via the tractor's terminal/dashboard. Failure to do so will likely trigger the related fault code 03.X.96 (Calibration Issue For Valve Switch 6).

8. 8

   Clear Codes

   Clear the stored 3.X.95 DTC using a diagnostic tool or the tractor's onboard diagnostic menu.