Massey Ferguson 3.01.8B – TECU: High Voltage On Auxiliary Valve Switch 4 (TECU)

The system has detected a short circuit to 12 V on the circuit for Auxiliary Valve Switch 4. This switch is typically the "FingerTIP 4" spool valve control located on the tractor's armrest console.

• 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

   Inspect the armrest console and the physical FingerTIP 4 switch for physical damage, liquid ingress, or sticking.

2. 2

   Disconnect the FingerTIP 4 switch and use a multimeter to check the signal wire on the harness side for a short to 12V battery power.

3. 3

   Test the switch itself for internal shorting.

4. 4

   Inspect the main connector at the Armrest Autotronic 5 / TECU module for bent pins, corrosion, or wiring chafing that could bridge the 12V supply to the switch signal wire.

1. 1

   Power Down

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

2. 2

   Access the Switch

   Carefully remove the trim/cover on the armrest console to expose the FingerTIP auxiliary valve switches.

3. 3

   Disconnect and Isolate

   Unplug the electrical connector for Auxiliary Valve Switch 4.

4. 4

   Repair/Replace

   If the wiring harness is shorted to a 12V power source, locate the chafe/pinch point in the armrest wiring and repair the wires. If the switch has failed internally (shorted to 12V), remove the retaining hardware and install a new FingerTIP switch.

5. 5

   Reassemble and Power Up

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

6. 6

   Calibration

   Clear the fault codes. Perform the auxiliary valve calibration procedure via the Datatronic/dashboard terminal.