User's Manual

Title : User manual of IM900 Immobilizer Spec. No. : N/A
Written by : SUNG HUN AHN Rev. No. : Revision A
Date :2007.11.07 Page : 8 / 10
Technical Center Automotive Electronics
4.3 Immobilizer Electronic Control Unit (ICU)
4.3.1 Tasks
The function of the Immobilizer System is shared between the ICU, Gateway and ECM.
The tasks of the Immobilizer Electronic Control Unit are executed.
4.3.2 Function
4.3.2.1 Normal Operation
• In the sleep mode of Immobilizer the LED on the IPC or clock is turned OFF.
• When Accessory is turned on, the system wakes up and tries to read out the transponder in the learning
enable mode.
• In case of the detection of a valid key, the response message communication with the ECM takes place.
The status LED off that means user key is learned and vial key.
• In case of the detection of a invalid key, the ICU will send LED flashing message ‘Tamper Detected’
and will change to Tamper. The status LED displays the Immobilizer state ‘invalid key’.
• After turning off the Accessory (Accessory OFF detection similar to the ECM Accessory OFF
detection), the Immobilizer changes to the Learn more standby status incase of 10 key was not coded.
4.3.2.2 ALDL-mode
During Accessory ON the Immobilizer ALDL-mode can be activated with one of the defined Immobilizer
ALDL-Function modes.
4.3.2.3 VIN-code Handling
The VIN-code is stored in the Immobilizer EEPROM. At the end of the electronic unit The VIN-code is a 8
byte value 0FFh.
4.3.3 Terminal of ICU
The Immobilizer has one connector. The terminal function is shown in the following table: