Operation CHARM: Car repair manuals for everyone.

General Information





Component Location





General Description

Information related immobilizer,that are classified as 2 (two) parts independently, is memorized in EEPROM. ECM check these 2 (two) information before proceeding immobilizer authentication. With synchronized both information, ECM starts immobilizer authentication procedure. If both information is not synchronized, ECM stops immobilizer authentication, Limphome function will not be activated, and memorizes DTC P1695. If DTC P1695 is retrieved again, after performing new key teaching procedure, ECM should be replaced with new one.

DTC Description

If key/password information in ECM is not matching or there is write error on EEPROM as hardware, DTC P1696 is set.

DTC Detecting Condition





Diagnostic Circuit










Signal Waveform & Data




Fig 1) It shows that ECU is learn status. (Just ignore rest of others parameter)
Although system is different from smarter system, it is possible only to check ECM status with GDS