John Deere 926.04 – SCO: Stepper Motor for E-SCV XIII, Supply Voltage Too Low

The supply voltage (BAT) for the stepper motor of the Electronic Selective Control Valve 13 (E-SCV XIII) has dropped below the required threshold, typically below 9 volts. This insufficient voltage prevents the stepper motor from functioning correctly, resulting in limited or no function of that specific selective control valve.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230R
• 6250R
• 6090M
• 6100M
• 6110M
• 6120M
• 6130M
• 6140M
• 6145M
• 6155M
• 6175M
• 6195M
• 8R 250
• 7760

1. 1

   Restart the vehicle's control system to see if the code is an intermittent software glitch.

2. 2

   Visually inspect around the batteries and alternator for any signs of damage, loose battery terminals, or accumulated debris that could cause a system-wide voltage drop.

3. 3

   Inspect all CAN Bus wiring and the specific wiring harness leading to the E-SCV XIII stepper motor for signs of chafing, shorts to ground, loose connections, or corrosion.

4. 4

   Use a multimeter to verify the power supply at the E-SCV XIII stepper motor connector. It must be receiving above 9 volts. If the voltage is low at the connector but normal at the battery, there is a wiring fault or a failing SCO controller.

1. 1

   Isolate the Circuit

   Disconnect the E-SCV XIII stepper motor and test the voltage coming from the SCO module.

2. 2

   Repair Wiring

   If the voltage is below 9 volts and wiring damage is found (shorts or corrosion), repair or replace the affected harness section and secure all connections.

3. 3

   Replace the Stepper Motor

   If the wiring is intact, the supply voltage from the module is correct, but the motor pulls the voltage down or fails to operate, the E-SCV XIII stepper motor has internally failed and must be replaced.

4. 4

   Verify the SCO Module

   If the SCO module itself is failing to output the correct voltage to the valve and harness tests show no shorts, the SCO Control Unit may need to be recalibrated or replaced.

5. 5

   Clear Codes

   After repairs, restart the tractor and clear the codes to ensure the SCO 000926.04 fault does not return.