General Information

Immobilizer
P1677 Immobilizer-EMS VIN Data Error (EMS has different VIN) - General Information

Component Location





General Description

Immobilizer Control Unit (ICU) supplies power to the coil antenna, receives and analyses signal from the transponder, transmits signal to engine ECM/PCM and stores VIN(Not the number on the bulkhead of vehicle but Vehicle Identification Number for Immobilizer ) data which composes of ID code and password.

DTC Description

ICU stores VIN which composes of ID code and password. This DTC is defined that VIN of EMS is inconsistent data of ICU.

DTC Detecting Condition





Diagnostic Circuit Diagram










Signal Waveform & Data




Fig.1) A normal signal waveform of antenna and immobilizer communication when IG key(TP: Transponder) is OFF to ON.