Mitsubishi B1766 Verified _hot_ May 2026

: Transponder registered for another vehicle (or "Already learned by other vehicle").

Replacing the ETACS-ECU with a used unit without properly rewriting the VIN or reprogramming the keys. Verified Diagnostic & Fix Procedures mitsubishi b1766 verified

: If the car starts and B1766 does not reappear, the original key was likely from another vehicle or has a corrupted ID. You must replace that specific key and register its new ID. : Transponder registered for another vehicle (or "Already

: Attempt to start the vehicle with a different key that is confirmed to be registered to this specific vehicle. You must replace that specific key and register its new ID

The Mitsubishi diagnostic trouble code (DTC) specifically indicates that a transponder key registered for another vehicle is being used in the ignition. When the Electronic Total Automotive Control System (ETACS-ECU) or Immobilizer-ECU detects a key ID that has already been "learned" by a different car's security system, it triggers this code and typically prevents the engine from starting to prevent theft. Understanding Mitsubishi DTC B1766

: Owners who lose their original keys and source a used key from a salvage yard will trigger B1766 because the transponder chip in that used key is permanently "locked" to its original vehicle.