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/PCM 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.
The ECM/PCM sets DTC if there is any open or short circuit between the antenna coil and Immobilizer unit.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Data status receiving from transponder | 1. Open or short circuit in antenna coil 2. Faulty antenna Coil 3. Faulty ICU |
Threshold value |
•
Open or Short circuit | |
Detecting time |
•
1 time | |
DTC Erasing Condition |
•
Without a fault or using a GDS |
Fig.1) A normal signal waveform of antenna and immobilizer communication when IG key(TP: Transponder) is OFF to ON.
