John Deere 516705.18 – Rear Chassis Module (SCC): SCV 6 Valve Low Voltage

The system has detected that the voltage supplied to or returning from the Selective Control Valve (SCV) number 6 is below the normal operating threshold. This typically points to a wiring issue, a failing solenoid/actuator on the valve, or a power supply issue from the module.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R

1. 1

   Inspect the wiring harness running from the Rear Chassis Module (SCC) to the SCV 6 valve. Look for chafed wires, pinched harnesses, or corrosion inside the electrical connectors.

2. 2

   Use a multimeter to measure the voltage at the SCV 6 electrical connector while the system is active to verify if the voltage is genuinely low.

3. 3

   Check the main power and ground connections at the Rear Chassis Module (SCC) to ensure the module itself is receiving adequate voltage to distribute to the valves.

4. 4

   If the wiring tests fine, temporarily swap the electrical connection from SCV 6 to another known-working SCV (like SCV 5) to see if the low voltage code follows the valve actuator or stays with the harness/module.

1. 1

   Park and Secure

   Park the tractor on a level surface, lower all implements to the ground, and turn off the engine.

2. 2

   Relieve Hydraulic Pressure

   CRITICAL SAFETY STEP. Escaping fluid under pressure can penetrate the skin and cause serious injury. Relieve all hydraulic pressure in the system by cycling the SCV levers/controls before disconnecting any hydraulic lines.

3. 3

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical shorts and accidental actuation.

4. 4

   Locate and Disconnect

   Locate the SCV 6 valve assembly at the rear hydraulic stack. Disconnect the electrical wiring harness from the SCV 6 actuator.

5. 5

   Remove the Valve/Actuator

   If the valve or electronic actuator is deemed faulty, place a catch pan underneath to catch residual hydraulic oil. Unbolt the hydraulic lines and remove the mounting hardware securing the SCV block.

6. 6

   Install New Component

   Install the replacement SCV or actuator. Always replace the O-rings on the hydraulic fittings to prevent leaks.

7. 7

   Reassembly

   Reconnect the hydraulic lines and tighten all connections securely before applying pressure. Reconnect the electrical harness.

8. 8

   Test

   Reconnect the battery, start the tractor, and check for leaks using a piece of cardboard (never your hands). Clear the fault codes from the display and test the SCV 6 function to ensure the voltage issue is resolved.