Massey Ferguson 03.01.86 – TECU: High Amp Draw On Auxiliary Valve Switch 3 (TECU)

The electronic control system has detected a high current draw, specifically a short circuit to 0 V (ground), on the circuit for the third auxiliary valve switch.

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626

1. 1

   Check the wiring harness between the TECU and Auxiliary Valve Switch 3 for any visible damage, chafing, or pinched wires that could cause a short circuit to ground (0 V).

2. 2

   Inspect the connectors at both the switch (often located on the armrest/FingerTIP controls) and the TECU for damaged contacts, corrosion, or bent pins.

3. 3

   Use a multimeter to test Auxiliary Valve Switch 3 for internal short circuits.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical spikes during repair.

2. 2

   Access the Switch

   Remove the necessary trim panels on the armrest or side console to access the auxiliary valve switches (specifically Switch 3 / FingerTIP controls).

3. 3

   Inspect and Repair Wiring

   If the diagnostic checks revealed a short to ground in the wiring harness, repair the damaged section of the wire or replace the affected harness segment.

4. 4

   Replace the Switch

   If the wiring is intact but the switch itself is internally shorted, disconnect the switch from the harness and install a new Auxiliary Valve Switch.

5. 5

   Reassemble and Clear Codes

   Reconnect the battery, turn on the ignition, and use an AGCO EDT (Electronic Diagnostic Tool) or equivalent scanner to clear the 03.01.86 fault code from the TECU. Test the auxiliary valve operation to ensure the high amp draw does not return.