John Deere 2003.14 – Engine Control Unit (ECU): Incorrect CAN Message Received From Source Address 3

The Engine Control Unit is receiving corrupted, invalid, or unexpected data packets over the CAN network from the transmission controller (TCU).

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• John Deere 3029 Diesel Engines (Level 23 ECU)
• John Deere 4045 and 6068 Diesel Engines
• John Deere 9.0L PowerTech Engines
• John Deere Forestry Equipment (e.g., 540G-III and 548G-III Skidders)

1. 1

   Check the TCU for its own active fault codes, as a loss of power or ground to the TCU can cause it to broadcast incorrect or zero messages to the ECU.

2. 2

   Visually inspect the CAN bus wiring harness between the ECU and the TCU for signs of physical damage, chafing, loose connections, or corrosion.

3. 3

   Ensure all pins and connectors at both the ECU and TCU are properly seated and free from moisture or debris.

4. 4

   Use John Deere Service ADVISOR (or a compatible diagnostic scan tool) to check the integrity and update rate of the data being transmitted over the CAN network.

1. 1

   Power Down

   Turn off the machine and disconnect the negative battery cable to protect the electronic modules.

2. 2

   Isolate the CAN Bus

   Locate the diagnostic port or the connectors at the ECU and TCU.

3. 3

   Test CAN Resistance

   Using a multimeter, measure the resistance across the CAN High and CAN Low pins. A healthy CAN network should read approximately 60 ohms (indicating both 120-ohm terminating resistors are intact). If it reads 120 ohms, one resistor or a wire is broken. If it reads 0 ohms, the CAN lines are shorted together.

4. 4

   Repair Wiring

   If the wiring is damaged, repair or replace the affected section of the CAN harness or the connector pins.

5. 5

   Software Update

   If the wiring and resistance are perfectly intact, reconnect the battery and modules. Connect John Deere Service ADVISOR and check if the TCU requires a software update to the latest version to resolve communication bugs.

6. 6

   Replace Module

   If the wiring is good, the software is up to date, and the TCU is still broadcasting incorrect messages (or failing to communicate), the TCU itself is internally faulty and must be replaced.

7. 7

   Clear Codes

   After repairs, clear the 002003.14 code from the ECU and test operate the machine to ensure the transmission and engine are communicating properly.