Daewoo MATIZ Service Manual page 1163

The VIN code is calculated by the Immobilizer using a
random generator.
The VIN code is transmitted from the Immobilizer in the
release message communication only incase of using
an authorized key. Without an authorized key it is not
possible to getthe system VIN code.In case of ECM in-
ternal state is in Virgin mode or neutral mode the ECM
learns the system VIN code automatically after receiving
the first release response message.
To get a synchronized Immobilizer system (same VIN-
code in Immobilizer and ECM,authorized key) the DLC
test equipment has to be used for authorization of the
keys(first key coding). The usage of this test equipment
is restricted to authorized persons.
D Communication with the DLC-test equipment. Main
functions are the key coding procedure, the VIN-code
handling and the support for system test functions.
D Handling of the software watchdog
Operation
In the active mode of immobilizer (engine OFF, IG key
OFF) the status LED is blinking as mode A. When igni-
tion is turned ON, the system wakes up and tries to read
out the transponder.
In case of the detection of a valid key , The release mes-
sage communication with the ECM takes place. The sta-
tus LED displays the Immobilizer state "valid key".
After turning off the ignition(ignition OFF detection simi-
lar to the ECM ignition OFF detection), the Immobilizer
changes to the active mode. The status LED is blinking
as Mode A.
Data Link Connector (DLC) Mode
When the ignition is on, a scan tool can switch the immo-
bilizer control unit to the DLC mode for diagnostics, key
coding and ID coding.
D The status LED is turned off during DLC-mode
D The Immobilizer will answer all correct messages,
which are defined as Immobilizer messages.
ID Code Handling
One of 65,535 VIN codes is stored in the immobilizer
EEPROM.
The VIN code can be erased by using "Reset VIN code"
command of the scan tool.
When the immobilizer control unit calculates a new VIN
code, ECM VIN code should be reset to get identical
with the immobilizer control unit's.
During diagnostic procedures, the VIN code can be read
for comparison with the ECM VIN code by using the
scan tool's "Read immobilizer control unit VIN code"
command.
DAEWOO M–150 BL2
IMMOBILIZER ANTI-THEFT SYSTEM 9T – 11
SERIAL DATA LINK
Serial data can be exchanged between a scan tool and
the ECM and the Immobilizer control unit. The scan tool
connection is the data link connector (DLC).
ELECTRONIC CONTROL MOUDLE
(ECM)
D ECM in Virgin mode
In this mode, the ECM knows only the model vehicle
identifier code.
The engine can be locked/unlocked.
ECM requests to ICU the VIN number. As soon as the
ECM receives two correct consecutive communica-
tion frames with the same VIN code the ECM learns
it.
The VIN code will be stored in non-volatile memory at
the end of power latch phase. ECM enters in Learnt
mode.
D ECM in Learnt mode
In such a state, ECM checks on every communica-
tion, the correct encoding of the ICU.
If the code received is not correct, then the vehicle is
immobilized.
The coded 5 bytes of data emitted by ECM are a mix-
ture of MIN code and random.
The coded 5 bytes of data emitted by ICU are a mix-
ture of VIN code and random.
D ECM in Neutral mode
This mode is a special intermediate mode, used for
ICU replacement or immobilizer option installation.
ECM request to ICU the VIN number. As soon as the
ECM receives two correct consecutive communica-
tion frames with the same VIN code the ECM learns
it. The VIN code will be stored in non-volatile memory
at the end of power latch phase. ECM enters in
Learnt mode.
D After turning on the ignition the ECM will control the
engine in a normal way for starting and running while
waiting for a valid release response message from
the Immobilizer.
1. After receiving a response message including the in-
formation "ICU in learnt mode" and the correct sys-
tem VIN-code
→ the ECM enters the release state, which allows to
continue the running of the engine.
2. After receiving a response message including the in-
formation "ICU in learnt mode" and a wrong system
VIN-code
→ the ECM does not send a new request and enters
the blocked state, which causes the activation of the
immobilization actions of the engine.