John Deere 002006.09 – TCU / ACU / CAB: CAN BUS Fault in Gear Shift Module

A fault has been detected in the communication of the CAN BUS message related to the Direct Drive Gear Shift Module. This indicates a loss of communication or an abnormal message on the CAN bus, preventing the electronic control units from exchanging necessary data. This communication failure can directly affect the proper operation of the gear shift system.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 5075E

1. 1

   Restart the tractor to see if the fault is intermittent and clears upon a power cycle

2. 2

   Check for other active fault codes to determine if multiple components on the same CAN bus circuit are failing, indicating a shared harness issue

3. 3

   Inspect fuses related to the transmission and cab controllers for blown circuits

4. 4

   Inspect the wiring harness and connectors between the gear shift module and transmission control unit for chafing, corrosion, pinched wires, or rodent damage (especially behind the monitor, top rear of cab, and ECU/TCU)

5. 5

   Check main battery ground to the frame and cab/control module ground connections for tightness and corrosion

6. 6

   Measure CAN bus voltages with key on/engine off (CAN High yellow wire and CAN Low green wire should both read approximately 2.5V)

7. 7

   Measure CAN bus resistance at the diagnostic connector with the battery disconnected (should be approximately 60 ohms; 120 ohms indicates a missing or damaged terminating resistor)

1. 1

   Repair wiring or grounds

   If diagnostic checks reveal blown fuses, poor grounds, or damaged wiring/connectors, repair or replace the affected sections. Clear fault codes and retest.

2. 2

   Replace gear shift module

   If wiring is intact but the shifter is faulty, remove the console or armrest covers, disconnect the electrical connectors, unbolt the unit, and install a replacement gear shift lever.

3. 3

   Replace and program control unit

   If the TCU or ACU is determined to be the root cause, replace the control unit. The new unit must be programmed with John Deere Service ADVISOR software by a certified technician.