John Deere 2004.09 – Engine Control Unit (ECU) or Instrument Control Unit (ICU): No CAN Message Received From Source Address 4

The Engine Control Unit (ECU) or Instrument Control Unit (ICU) has lost communication with the Transmission Control Unit (TCU) assigned to Source Address 4 due to an abnormal update rate or missing message.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 3029
• 4045
• 6068
• 8.1L
• 9.0L
• 12.5L
• 540G-III
• 548G-III
• 640
• 648G-III
• 460D
• 540H
• 548H
• 210LJ
• 210K EP
• 6330
• 6430
• 7130
• 7230
• 7330
• 7430
• 7530

1. 1

   Restart the engine to see if the code clears (momentary CAN bus initialization glitch)

2. 2

   Check for accompanying voltage or power supply codes in the ECU or TCU

3. 3

   Verify TCU power and ground by checking fuses, relays, and ground straps supplying the Transmission Control Unit

4. 4

   Test CAN bus wiring integrity between the ECU and TCU for continuity

5. 5

   Measure resistance across the CAN bus network to ensure terminating resistors are intact (should read 60 ohms)

1. 1

   Inspect the Harness

   Visually inspect the wiring harness connecting the ECU/ICU to the TCU. Look for chafed wires, corrosion, or backed-out pins at the connectors.

2. 2

   Repair Wiring

   If an open circuit, short to ground, or short to voltage is found on the CAN High or CAN Low lines, repair the wiring harness or replace the damaged connector pins.

3. 3

   Replace Terminating Resistor

   If the CAN bus resistance is out of specification (e.g., 120 ohms or open), locate and replace the faulty CAN bus terminating resistor.

4. 4

   Replace the TCU

   If the wiring is intact, the CAN bus resistance is correct, and the TCU is receiving proper power and ground but still not communicating (Source Address 4 remains missing), the Transmission Control Unit has failed internally and must be replaced.

5. 5

   Calibrate/Program

   If a new TCU is installed, it may require dealer programming or calibration to sync with the ECU and machine options.