Massey Ferguson 03.01.87 – TECU: High Voltage On Auxiliary Valve Switch 3 (TECU) / Calibration Issue For Valve Switch 3 (TECU)

Short circuit to 12V on the circuit for the 3rd auxiliary valve switch (FingerTIP 3 switch on the armrest), or a failure to complete the switch's calibration procedure.

• 7724S
• 5712SL
• 7722S
• 7722
• 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

   Inspect the physical condition of the FingerTIP 3 auxiliary valve switch on the armrest console for sticking buttons, moisture intrusion, or physical damage.

2. 2

   Access the wiring under the armrest and check connector X587 for corrosion, pushed-out terminals, or moisture.

3. 3

   Using a multimeter, test the signal wire from the switch to the TECU for a short to 12V (a reading of 12V in neutral confirms a short to power).

4. 4

   Attempt to recalibrate the auxiliary valve switches via the dashboard diagnostic menu or AGCO Electronic Diagnostic Tool (EDT) to rule out a simple calibration failure.

1. 1

   Disconnect Power

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

2. 2

   Access the Armrest Console

   Carefully remove the cladding/screws securing the armrest control panel to expose the underside of the FingerTIP switches.

3. 3

   Isolate the Fault

   Disconnect the FingerTIP 3 switch (Connector X587). Reconnect the battery and turn the key to the ON position. If the code changes from 'High Voltage' (Short to 12V) to 'High Amp Draw / Short to 0V' (Code 03.00.86 / AR 31), the wiring harness is good, and the switch itself has failed internally. If the code remains 03.01.87, the short to 12V is in the wiring harness between the armrest and the TECU.

4. 4

   Replace the Component

   If the switch is faulty, unbolt the retaining plate for the FingerTIP 3 switch and install the replacement. If the harness is shorted, trace the wire back to the TECU and repair the chafed/melted section.

5. 5

   Reassemble and Calibrate

   Reinstall the armrest console. Turn the tractor on and perform the mandatory spool valve calibration procedure so the TECU can learn the new switch's min/max/neutral potentiometer values.

6. 6

   Clear Codes

   Clear the inactive fault codes from the TECU memory.