Massey Ferguson 0A.70.13 – Transmission Control Unit (TCU): External Hydraulic Valve 7 Issue

Message error for hydraulic controls on machine and Control unit transmission, indicating a communication or connection problem on the CAN bus drivetrain between the hydraulic controls and the transmission control unit.

• 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

   Scan for secondary codes to see if there are other error codes present for the servo valves or hydraulic controls that might pinpoint a specific short circuit

2. 2

   Inspect the cable harness on the CAN bus drivetrain

3. 3

   Perform pin-to-pin testing for continuity and check for shorts on the harness between the Transmission Control Unit (D7930) and the hydraulic controls (D7971), specifically focusing on connections D7930/B1 to D7971 and D7930/B2 to D7971

1. 1

   Connect Diagnostic Tool

   Plug a compatible interface device into the tractor's diagnostic port to confirm the 0A.70.13 code and view the signal in the display's diagnostic menus.

2. 2

   Access the TCU and Hydraulic Modules

   Locate the Transmission Control Unit (D7930) and the external hydraulic valve control module (D7971).

3. 3

   Inspect the Harness

   Visually inspect the CAN bus wiring harness connecting these two modules for chafing, corrosion, or loose connector pins.

4. 4

   Repair Wiring

   If the wiring between D7930/B1, D7930/B2, and D7971 is damaged, repair or replace the affected harness section.

5. 5

   Inspect Valve 7

   If the CAN bus wiring is intact, inspect External Hydraulic Valve 7 directly for physical damage or a failed solenoid connection.

6. 6

   Clear Codes and Test

   Once the wiring is repaired or the valve is replaced, use the diagnostic tool to clear the DTCs. Cycle the tractor's hydraulic controls to ensure the code does not return and full functionality is restored.