John Deere E02 – RCU: Right Control Unit Diagnostic Trouble

The system has detected a fault related to the Right Control Unit (RCU). This fault code represents a category of potential problems related to the RCU's operation, its power supply, or its communication with other components on the vehicle's CAN bus network. Further investigation using specific SPN and FMI sub-codes is required to determine the exact nature of the issue, which can range from high voltage and internal memory failures to sensor or CAN bus communication errors.

• 9540 WTS
• 9560 WTS
• 9580 WTS
• 9640 WTS
• 9660 WTS
• 9680 WTS
• 9560 STS
• 9660 STS
• 9760 STS
• 9860 STS
• 9570 STS
• 9670
• 9670 STS
• 9770 STS
• 9870 STS
• S550
• S560
• S650
• S660
• S670
• S670H
• S680
• S680H
• S685
• S685H
• S690
• S690H
• S760
• S770
• S780
• S785
• S790
• T550
• T560
• T660
• T670
• W540
• W550
• W650
• W660
• C670

1. 1

   Access the machine's diagnostic display to retrieve and record the specific SPN and FMI codes nested under the E02 header

2. 2

   Visually inspect the wiring harnesses and connectors associated with the Right Control Unit and any related sensors for damage, corrosion, or loose connections (wiggling wires in the armrest may reveal a bad connection)

1. 1

   Diagnose Sensor Voltage Issues (SPN 96, 1508, 1509)

   If the sub-code indicates a sensor voltage issue (e.g., Fuel Level, Hydraulic Oil Temp, Main Gearcase Oil Temp): Inspect the wiring and connectors for the specific sensor. Test the sensor to ensure it is functioning within its specified range. If the sensor and wiring are in good condition, the issue may lie within the RCU itself.

2. 2

   Resolve Boot Block Program Error (SPN 628, FMI 12)

   If the controller cannot exit the boot block program: Turn the key switch to the OFF position. Disconnect the connectors for the affected control unit, wait 30 seconds, and reconnect them. Attempt to reprogram the controller with the latest software. If the condition persists, replace the Right Control Unit.

3. 3

   Address EEPROM Failure (SPN 630, FMI 11)

   If the EEPROM failed test on power up: This indicates an internal memory failure in the control unit. Replace the Right Control Unit if the condition persists.

4. 4

   Troubleshoot CAN Bus Communication (SPN 639, FMI 19)

   If CAN Bus messages are not being transmitted or received correctly: Check the CAN bus wiring and connectors for faults. If wiring is intact, this error can be a symptom of a failing control unit on the network.