John Deere 002145.09 – TCU: CAN BUS Message Fault in Direct Drive Gear Shift Module

A communication failure has been detected on the CAN bus involving the Direct Drive Gear Shift Module. The .09 FMI indicates an abnormal update rate, meaning the Transmission Control Unit (TCU) is not receiving messages from the gear shift module as expected. This can be caused by a complete loss of communication or intermittent messaging, which disrupts the proper operation of the gear shift system.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R

1. 1

   Check the diagnostic display for other active fault codes to rule out a wider CAN bus network problem

2. 2

   Inspect the battery and charging system to ensure the battery is fully charged and the alternator is functioning correctly, as low voltage causes unpredictable CAN behavior

3. 3

   Visually inspect the wiring harness and connectors for the Direct Drive Gear Shift Module and TCU for chafing, corrosion, pinched wires, or loose connections

4. 4

   Perform a CAN bus resistance check: disconnect the battery and measure resistance between CAN High (Yellow) and CAN Low (Green). It should be approximately 60 Ohms (120 Ohms indicates a faulty or disconnected terminating resistor)

5. 5

   Check with a John Deere dealer for available software updates for the transmission or vehicle control units

1. 1

   Rectify basic electrical issues

   Address any low battery voltage, corroded connectors, or damaged wiring found during inspection. Clean, repair, or replace wiring and connectors as necessary. Clear fault codes and test operate the machine.

2. 2

   Isolate the faulty module

   If wiring and basic checks are satisfactory, the issue likely lies with the Direct Drive Gear Shift Module or the TCU.

3. 3

   Replace Direct Drive Gear Shift Module

   Replace the gear shift module as it is the primary suspect. Note that software calibration may be required after replacement.

4. 4

   Consult dealer for advanced diagnostics

   If replacing the gear shift module does not resolve the issue, consult a dealer to diagnose the TCU or more complex wiring issues.