John Deere 523889.18 – SIC (Selective Control Valve Control Unit): A38 - Stepper Motor ESCV 3 (Electro-Hydraulic Section Control Valve 3), Hydraulic Oil Temperature and Supply Voltage Too Low

This code is generated when the system voltage (battery voltage) measured at the stepper motor of ESCV 3 drops to between 9 and 11 volts, and the hydraulic oil temperature is too low (typically between 25°C / 13°F and operating temperature). The operator display will typically show a blue informational warning stating: 'SCV III inoperative. Wait until oil has warmed up'.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230
• 6330
• 6430
• 7430
• 7530

1. 1

   Allow the tractor to run and the hydraulic oil to reach normal operating temperature

2. 2

   Check the battery voltage and alternator output to ensure system voltage is above 11 volts

3. 3

   Inspect the wiring harness and connectors between the SIC control unit and the A38 Stepper Motor for corrosion, loose pins, or chafing

4. 4

   Verify that the ISOBUS connection between the tractor and implement is secure

1. 1

   Warm the Hydraulic System

   Start the tractor and allow the hydraulic oil to warm up. If the code clears and SCV 3 resumes normal operation, no mechanical repair is needed—this is normal system protection.

2. 2

   Resolve Voltage Drops

   If the code persists after the oil is warm, test the voltage at the ESCV 3 connector. If it is between 9-11V while the battery reads 12V+, trace the harness back to the SIC module to locate and repair the high-resistance wiring fault.

3. 3

   Check Fluid Type

   Ensure the tractor is filled with standard John Deere HY-GARD or BIO-HY-GARD II. OEM manuals explicitly warn against using HY-GARD LOW VISCOSITY in these specific Premium tractors, as it can affect hydraulic temperature and pressure readings.

4. 4

   Test/Replace the Stepper Motor

   If the wiring is intact, voltage is correct, and the oil is warm but the code remains active, the A38 Stepper Motor's internal temperature/voltage sensor has likely failed. Use John Deere Service ADVISOR to run an interactive test on the E-SCV 3 Stepper Motor. If it fails, replace the stepper motor.