General Information

Immobilizer
P1691 Immobilizer-Antenna Coil Error - General Information

Component Location





General Description

This wireless communication runs on Radio frequency. The antenna coil is mounted on the top of ignition lock for RF transmission and receiving. The RF signal from the transponder received by the antenna coil is converted into messages for serial communication by the Immobilizer unit. And the received messages from the ECM are converted into an RF signal, which is transmitted, to the transponder by the antenna. Coil antenna provides energy to the transponder key and retrieves signal from the transponder and send it to Immobilizer unit.

DTC Description

The PCM/ECM sets DTC if there is any open or short circuit between the antenna coil and Immobilizer unit

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.