John Deere 524180.19 – TCU (Transmission Control Unit) / Transmission Module IVT (PTA): Missing Info On The CAN BUS, Transmission Module IVT (PTA) / Incorrect CAN BUS Message, Status of Come-Home Mode from UIC

The User Interface Controller (UIC) is unable to determine the status of the come-home mode (LHR) and fails to provide the CAN BUS with the relevant data, causing the system to transmit a replacement value.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230
• 6330
• 6430
• 6530
• 6630
• 6830
• 6930

1. 1

   Connect a diagnostic tool and check the UIC (User Interface Controller) for any active companion codes related to the reverse drive lever or come-home mode switch.

2. 2

   Verify the CAN BUS network is intact between the UIC and the TCU by checking for voltage irregularities on the CAN High and CAN Low lines.

3. 3

   Inspect the wiring harnesses and connectors linking the UIC (often located in the cab/armrest area) and the TCU for corrosion, backed-out pins, or chafed wires.

1. 1

   Address UIC Faults First

   If the diagnostic scan reveals codes in the UIC related to the reverse drive lever or come-home mode switch (e.g., UIC 523966 series codes), troubleshoot and replace the faulty switch or sensor first.

2. 2

   Test Wiring Continuity

   Disconnect the harness at the UIC and the TCU. Use a multimeter to check for continuity on the CAN BUS wires between the two modules. Also, check for short-to-ground or short-to-power on these lines.

3. 3

   Repair Wiring

   If resistance is out of specification or a short/open is found, repair the affected section of the CAN BUS wiring harness or replace the harness segment.

4. 4

   Software Update / Module Replacement

   If the wiring is perfectly intact, the switches are functioning, and the UIC is still failing to broadcast the come-home mode status, the UIC may require a software reflash. If a reflash fails, the UIC itself must be replaced.

5. 5

   Clear and Verify

   Reconnect all modules, clear the stored codes in both the TCU and UIC, and test drive the tractor (cycling through forward, reverse, and neutral) to ensure the code does not return.