John Deere 628.12 – Various (AIC, ATC, CAB, PTP, TEC, TSC): Control Unit Internal Fault / Programming in Progress / EOL Data Fault

Code 000628.12 indicates an internal electronic malfunction within a specific control unit, causing it to fail to boot up properly, or it is stuck in programming mode/EOL data fault. Code 516446.09 indicates the Armrest Interface Control Unit (AIC) is failing to receive a LIN message from the armrest multi-function lever module (hydraulic joystick).

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5E Series
• 5M Series
• 6M Series
• 6R Series
• 7R Series
• 8R Series
• 9R Series
• 9RT Series
• Combines
• Motor Graders
• Skid Steers

1. 1

   If diagnosing 000628.12 (Internal Fault): Cycle power by turning the key switch off, waiting a few minutes, and restarting the tractor to clear potential boot-up glitches.

2. 2

   If diagnosing 000628.12 (Internal Fault): Verify that the affected control unit is receiving a stable and adequate power supply by checking batteries, alternator, and fuses.

3. 3

   If diagnosing 000628.12 (Internal Fault): Inspect the specific ECU throwing the code for physical damage, overheating, or corrosion at the connector pins.

4. 4

   If diagnosing 516446.09 (Joystick Communication): Inspect the LIN Bus wiring harness between the Armrest Interface Control (AIC) and the multi-function lever for pinched, chafed, or broken wires, especially near the armrest hinge.

5. 5

   If diagnosing 516446.09 (Joystick Communication): Ensure the connector at the base of the hydraulic joystick is fully seated and free of bent pins or corrosion.

1. 1

   Diagnose software corruption

   For 000628.12 (Internal Fault): If a power cycle does not clear the code, the control unit's software may be corrupted.

2. 2

   Reprogram control unit

   Connect John Deere Service ADVISOR and attempt to reprogram/flash the affected control unit with up-to-date software.

3. 3

   Replace control unit

   If the module refuses to take the programming or the internal fault persists, the control unit itself has suffered a hardware failure and must be replaced.

4. 4

   Disconnect battery

   For 516446.09 (Joystick Communication): Disconnect the machine's battery to prevent electrical shorts.

5. 5

   Remove covers

   Remove the plastic covers on the CommandARM / armrest assembly to expose the wiring.

6. 6

   Test continuity and repair wiring

   Perform a continuity test on the LIN Bus wires between the joystick module and the AIC module. Repair any broken wires found in the harness.

7. 7

   Replace Multi-Function Lever Module

   If the wiring is completely intact and has good continuity, the LIN transceiver inside the joystick has likely failed. Replace the Multi-Function Lever Module.

8. 8

   Replace and reprogram AIC

   If replacing the lever does not restore communication, the fault lies within the Armrest Interface Control Unit (AIC), which will need to be replaced and reprogrammed.