Problem:
One customer gave feedback that AutoTuner Master Tuning Tool was unable to read SID209 via OBD. The software indicated that the ECU has already been unlocked using a different tool.
Key Information:
When an ECU is unlocked or patched by one tool, it often becomes incompatible with others.
Attempting to access it again with a different tool (like AutoTuner) – especially in boot mode – may cause ECU failure or a complete loss of communication.
Recommended Solution:
Do not attempt boot mode with AutoTuner, as this is high-risk.
Since the ECU appears to have been previously tuned, use dedicated restoration software like FORscan to reload the original firmware, or recover the ECU using IDS/FDRS.
