Description
The immobilizer system will disable the vehicle unless the proper ignition
key is used, in addition to the currently available anti-theft systems such
as car alarms, the immobilizer system aims to drastically reduce the rate of
auto theft.
1. |
Transponder (TP) – IMMO ECU Communication

TP Read Protocol
(1) |
IMMO_ECU after IGN on(or CPU Reset cancellation) is sent
Challenge to TP and confirmed Serial Number and Signature.
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(2) |
When response of input transponder is not correct, input
is retry.
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(3) |
When response of input transponder is correct, The data
that calculate Encryption operation in the EEPROM program compared
with received data from TP.
When Codes is same, input is finished.
If the codes are not same, input are continued until when
codes are same.
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(4) |
If IMMO_ECU EEPROM code is not programming, when correct
transponder is inputted (CRC Check OK), input is finished.
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(5) |
After IGN1 on(CPU Reset cancellation), IMMO_ECU is reading
the maximum 5times Transponder Code
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(6) |
In the IGN1 ON&EMS_state=Lock state, when received ANKNOWLEDGE,
TP is re-authenticated

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2. |
TP / IMMO ECU / EMS Authentication Flowchart

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Components Operations
ECM (Engine Control Module)
1. |
The ECM(PCM) (A) carries out a check of the ignition key using
a special encryption algorithm, which is programmed into the transponder
as well as the ECM simultaneously. Only if the results are equal, the
engine can be started. The data of all transponders, which are valid
for the vehicle, are stored in the ECM.
ERN (Encrypted Randorn Number) value between EMS and encrypted
Immobilizer unit is checked and the validity of coded key is decided
by EMS.

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ENCRYPTED Immobilizer unit (A)
The Immobilizer carries out communication with the built-in transponder
in the ignition key. This wireless communication runs on RF (Radio frequency
of 125 kHz). The Immobilizer is mounted behind of the crash pad close to center
cross bar.
The RF signal from the transponder, received by the antenna coil, is converted
into messages for serial communication by the Immobilizer device. And, the received
messages from the PCM(ECM) are converted into an RF signal, which is transmitted
to the transponder by the antenna.
The Immobilizer does not carry out the validity check of the transponder
or the calculation of encryption algorithm. This device is only an advanced
interface, which converts the RF data flow of the transponder into serial communication
to the ECM and vice versa.


TRANSPONDER
The transponder (A) has an advanced encryption algorithm. During the key
teaching procedure, the transponder will be programmed with vehicle specific
data. The vehicle specific data are written into the transponder memory. The
write procedure is once only; therefore, the contents of the transponder can
never be modified or changed.


Antenna coil
The antenna coil (A) has the following functions.
- |
The antenna coil supplies energy to the transponder.
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- |
The antenna coil receives signal from the transponder.
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- |
The antenna coil sends transponder signal to the Immobilizer.
It is located directly on the shroud.
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Replacement
Problems And Replacement Parts:
Problem
Part set
Scan tool required?
All keys have been lost
Blank key (4)
YES
...
See also:
Schematic Diagrams
System circuit diagram
Connector pin number
Pin No.
Discription
Remark
1
IG ON
...
Headlamp welcome function
When the headlight switch is in the ON or AUTO position and all doors (and tailgate)
are closed and locked, if you press the door unlock button on the transmitter (or
smart key), the headlights wi ...
Checking the coolant level
WARNING Removing radiator cap
• Never attempt to remove the radiator cap while the engine is operating
or hot. Doing so might lead to cooling system and engine damage and could result
in ...