John Deere 3598.06 – OIC / FCC: Supply Voltage 2 of the Cab Control Unit, Current Too High / Wakeup Output Circuit Current High

The control software has detected an excessive current draw (high amperage) on the wakeup output circuit or supply voltage 2 circuit. This typically suggests a short to ground in the wiring harness or an internal short within a connected component that is drawing too much power.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8245R
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R
• 8370R
• 8400R
• 9470RT
• 9520RT
• 9570RT
• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC
• 7180
• 7280
• 7380
• 7480
• 7580
• 7780
• 7980
• CH570
• 3520

1. 1

   Cycle the key switch and tractor power to see if the code is an intermittent glitch that clears on reboot

2. 2

   Check the power supply for the cab control unit to ensure it is functioning correctly and not supplying excessive voltage

3. 3

   Visually inspect all wiring and connections between the OIC/FCC and the Cab Control Unit for signs of chafing, pinched wires, loose connections, or corrosion

4. 4

   Use a digital multimeter to measure the voltage and current at the supply lead for the wakeup circuit to ensure it does not exceed the specified range

5. 5

   Verify if the control software is updated to the latest version, as firmware updates can sometimes resolve voltage regulation logic errors

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery terminal to prevent electrical spikes during testing.

2. 2

   Isolate the Circuit

   Disconnect the wiring harness connector at the Cab Control Unit and the OIC/FCC module.

3. 3

   Check for Continuity to Ground

   Using a multimeter set to ohms, probe the Supply Voltage 2 / Wakeup Output wire against a known good chassis ground. If there is continuity, the wire is shorted to ground.

4. 4

   Repair Wiring

   If a short is found, trace the harness to locate the damaged section. Repair the wire using OEM-approved splicing techniques and heat shrink, or replace the affected harness section.

5. 5

   Test the Modules

   If the wiring tests fine (no short to ground), the excessive current draw is likely internal to the Cab Control Unit or the OIC/FCC module. Reconnect the modules one at a time while monitoring the current draw to identify which unit is internally shorted.

6. 6

   Replace Faulty Component

   Replace the module that is causing the high current draw.

7. 7

   Update and Calibrate

   After replacing a module, use John Deere Service ADVISOR to flash the latest firmware, calibrate the new module, and clear the stored 003598.06 fault code.

8. 8

   Verify Repair

   Run the machine and monitor system performance to ensure the error does not recur.