Massey Ferguson 03.02.97 – TECU: High Amp Draw On Auxiliary Valve Switch 7 (TECU)

A short circuit to 0 V (short to ground) on the electrical circuit for the 7th auxiliary spool valve switch. The controller detects that the current draw exceeds the expected operating parameters, indicating power is going directly to ground.

• 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

   Inspect the wiring harness running from the armrest (FingerTIP controls or joystick) to the TECU for pinched wires, chafing against the seat suspension/cab frame, or melted insulation.

2. 2

   Disconnect the connector for Auxiliary Valve Switch 7 at the armrest and inspect the pins for corrosion, moisture, or bent terminals that could be bridging the circuit to ground.

3. 3

   With the switch disconnected, use a multimeter to measure the resistance between the switch's signal wire and a known good chassis ground. Continuity (0 ohms or very low resistance) indicates the wiring harness is shorted to ground.

4. 4

   Test the switch itself for an internal short. If the switch shows continuity to ground when it shouldn't, or fails to show proper resistance values compared to a known good switch (like Aux Valve 6), it has failed internally.

1. 1

   Power Down

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

2. 2

   Access the Switch

   Remove the trim panels on the right-hand armrest to access the underside of the FingerTIP control module or joystick where Auxiliary Valve Switch 7 is housed.

3. 3

   Isolate the Fault

   Based on your diagnostic checks, proceed to either repair the harness or replace the switch.

4. 4

   Harness Repair

   If the harness is chafed, cut out the damaged section of the wire, solder in a new section of equivalent gauge, and seal it with dual-wall heat shrink tubing.

5. 5

   Switch Replacement

   If the switch is internally shorted, unclip the faulty switch from the armrest bezel, disconnect its pigtail, and snap the new OEM switch into place.

6. 6

   Reassembly

   Reconnect the armrest wiring and reinstall the trim panels.

7. 7

   Clear Codes

   Reconnect the battery. Turn the key to the ON position. Use the tractor's dashboard diagnostic menu or the AGCO EDT (Electronic Diagnostic Tool) to clear the stored 03.02.97 fault code.

8. 8

   Operational Test

   Start the tractor and operate Auxiliary Valve 7 to ensure the high amp draw code does not return and the hydraulic spool responds correctly.