Massey Ferguson 03.03.9A – TECU: High Amp Draw On Auxiliary Valve Switch 8 (TECU)

The system has detected an abnormally high electrical current (amperage) draw on the circuit for Auxiliary Valve Switch 8. This typically indicates a short circuit to ground (0 V) within the switch, the solenoid it controls, or the wiring harness connecting them.

• 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

   Visually inspect Auxiliary Valve Switch 8 and its corresponding hydraulic spool valve solenoid. Look for pinched wires, chafing, or melted insulation on the wiring harness.

2. 2

   Disconnect the switch and the TECU harness connectors to check for water ingress, bent pins, or corrosion.

3. 3

   With the battery disconnected, use a multimeter to check the continuity of the signal wire for Switch 8 to ground. Continuity to ground indicates a shorted harness.

4. 4

   Test the resistance of the switch and the valve solenoid. Internal resistance near zero indicates a dead short and internal component failure.

1. 1

   Disconnect Power

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

2. 2

   Access the Switch/Solenoid

   Depending on your diagnostic findings, access either the armrest console to reach the switch or the rear hydraulic valve block to reach the solenoid.

3. 3

   Repair Wiring (If Applicable)

   If a short to ground was found in the harness, splice and solder the damaged wire, sealing it with heat-shrink tubing.

4. 4

   Replace the Faulty Component

   If the switch or solenoid is internally shorted, unclip the wiring harness, remove the mounting hardware, and install the replacement part.

5. 5

   Reassemble and Reconnect

   Secure all panels and reconnect the negative battery terminal.

6. 6

   Calibration

   Turn the key to the ON position. Run the TECU spool valve calibration procedure via the tractor's Datatronic/terminal screen to normalize the new switch.

7. 7

   Clear Codes

   Clear the stored 03.03.9A fault code from the TECU memory and test the hydraulic valve operation to ensure the high amp draw does not return.