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IMMOBILIZER SYSTEM 9W-3
SYSTEM DESCRIPTION
Gasoline Version
The Immobilizer System consists of an electronic device with integrated coil, called ‘Active Antenna’, the crypto
transponder, which is integrated in the ignition key, and the engine management system (EMS).
The Active Antenna is mounted at the ignition lock and handles the following tasks :
lTo supply the transponder with power
lTo receive the data from the EMS and transmit it to the transponder
lTo receive and demodulate the data from the transponder and transmit it to the EMS
The whole Immobilizer software, the authentication and the management of valid keys is completely managed by the
EMS.
Immobilizer system for gasoline vehicle
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IMMOBILIZER SYSTEM 9W-7
System Integration
The med 98.2 immobilizer is an anti-theft protection device allowing the start of the engine only if a specific authorization
is obtained during the start up phase. The med 98.2 will allow (prohibit) the start of the engine by driving ON (OFF) an
internal solenoid valve.
The med 98.2 is a single unit integrating the following subsystem :
la valve that allows (valve open) or blocks (valve closed) the fuel flow through the engine fuel system
la microprocessor control system to control and activate the valve during the start up of the engine, in order to
allow the start up only when a specific permission is given
the med 98.2 task is, therefore, to prevent the non authorized start up of the engine.
The functional unit includes also a basic set of electronic components whose function is to reduce its dependence on
the microprocessor control system: a part from a short temporarily period, during the start up phase, the electronics
allows the control system to excite and open the valve, but it doesn’t allow to close it.
The valve can be shut off only after the KL 15 has been deactivated.
The structure allows to obtain the highest degree of safe-operation (functionality fail-start): a failure in the
microprocessor unit cannot cause the shut-off of the valve. The main consequence of this type of failure is to prevent
the next engine start up.
As a result of the above considerations, the med 98.2 immobilizer can realize its anti-theft functionality only in conjunction
with a control device: the ICU.
The ICU, when requested, sends a coded message to med 98.2 according to a settled communication protocol. The
med 98.2 will allow the start of the engine based upon this message.
In addition to the basic anti-theft functionality, the 98.2 immobilizer provides a number of diagnostic services when it
is connected to an external test instrument (SCAN-100). Those connections are depicted in the following integration
diagram (Fig. 1), where the dashed line indicates a temporary link for diagnostic purposes, and the shaded area the
med 98.2 system’s physical boundaries:
Fig. 1 - System Integration
Explanation of symbols:
med 98.2Immobilizer
ICU Immobilizer Control Unit
TESTER Device that can be connected for diagnostic purposes
K-LINESerial line for communication with ICU
KL15 Ignition key (Power supply for med 98.2)
GND Ground
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9W-8 IMMOBILIZER SYSTEM
DefectsPossible cause Remedy
No communication with
transponder1. Defective wiring harness
- Power supply/Open/short of ground
- Open/short of signal terminal or
mis-conneting(between ECU
terminal No. 13 and 14)1. Connect/replace the wire correctly.
2.1 Replace the transponder
2.2 Immobilizer programming 2. Damaged transponder
3. Replace the antenna3. Defective antenna
4.1 Replace the ECU
4.2 Replace all transponder of the keys
4.3 Immobilizer programming 4. Defective ECU
No immobilizer
programming
(Components and
wiring harnesses are
normal but codes in
ECU and transponders
are not registered
normally)1. Replace the transponders and ECU
with new
; Immobilizer programming is not
performed1. Perform immobilizer programming
2. Replace transponders only(new)
; Immobilizer programming is not
performed2. Perform immobilizer programming
3. Replace ECU only(new) 3.1 Replace the transponders with new
3.2 Perform immobilizer programming
4. Replace the transponder only
; Programmed for other ECU4.1 Replace the transponders with new
4.2 Perform immobilizer programming
5. Re-programming is not performed
after clearing transponder code stored
in ECU that normally used system5. Immobilizer programming
Notice
1. Application of ex-programmed transponder into other ECUs.
; In this case, it can not be removed for the settled “lock bit” in transponder even though you perform immobilizer
problem normally. Moreover it is impossible to start engine, so replace the transponder with new and perform
immobilizer programming.
DIAGNOSIS
GASOLINE ENGINE
Cause and Remedy for Defective When Diagnosed by Scanner
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IMMOBILIZER SYSTEM 9W-9
Check and Remedy when Engine Does not Start
Starter operates normally?
Ye s No
lCheck fuses (No. 8 and 27)
lCheck ECU and antenna power
ECU terminal
- No. 12 (Power)
- No. 11 (Ignition)
- No.5/10 (Ground)
lCheck battery voltage
lCheck battery wiring
lCheck signal wires between ECU
and antenna
- Immobilizer No.3 wire (0.5BY) =
ECU No. 14 pin (0.75BW)
:
Writing immobilizer code number
- Immobilizer No.4 wire (0.5Y) =
ECU No.13 pin (0.75Y)
: Reading immobilizer cod number
lCheck starter wires
lCheck TCU wires (only for 5-
speed automatic transmission)
lCheck starter and TCU
lECU No.2 pin : check normal
signal of the starter 1)
- Engine cranking voltage : 8-15V
lCheck engine speed sensor wires
and replace
lReplace immobilizer antenna
lReplace transponder and ECUNotice
1)
MSE ECU equipped vehicle is designed to
make fuel injection when the engine speed
for initial cranking is over 450rpm if there
are no start switch inputs in ECU No. 2 pin.
If transponder and ECU are replaced,
perform programming.
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9W-10 IMMOBILIZER SYSTEM
1. Connect/replace the wire correctly
2. Replace the transponder
3.1 Replace the valve
3.2 Turn Ign sw on
3.3 Turn Ign sw OFF & ON
DefectsPossible cause Remedy
No communication with
transponder1. Defective wiring harness
- Power supply/Open/short of ground
- Open/short of signal terminal or
mis-conneting(between ICU
terminal No. 13 and 14)1. Connect/replace the wire correctly.
2.1 Replace the transponder
2.2 Immobilizer programming 2. Damaged transponder
3. Replace the antenna3. Defective antenna
4.1 Replace the ICU
4.2 Replace all transponder of the keys
4.3 Immobilizer programming 4. Defective ICU
No immobilizer
programming
(Components and
wiring harnesses are
normal but codes in
ICU and transponders
are not registered
normally)1. Replace the transponders and ICU
with new
; Immobilizer programming is not
performed1. Perform immobilizer programming
2. Replace transponders only(new)
; Immobilizer programming is not
performed2. Perform immobilizer programming
3. Replace ICU only(new) 3.1 Replace the transponders with new
3.2 Perform immobilizer programming
4. Replace the transponder only
; Programmed for other ICU4.1 Replace the transponders with new
4.2 Perform immobilizer programming
5. Re-programming is not performed
after clearing transponder code stored
in ICU that normally used system5. Immobilizer programming
Notice
1. Application of ex-programmed transponder into other ICUs.
; In this case, it can not be removed for the settled “lock bit” in transponder even though you perform immobilizer
problem normally. Moreover it is impossible to start engine, so replace the transponder with new and perform
immobilizer programming.
DIESEL ENGINE
Cause and Remedy for Defective When Diagnosed by Scanner
No communication with
valve1. Defective wiring harness
- Power supply/Open/short of ground
- Open/short of signal terminal or
mis-conneting(between ICU
terminal No. 13 and 14)
2. Defective ICU
3. Defective valve
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IMMOBILIZER SYSTEM 9W-11
Check and Remedy when Engine Does not Start
Starter operates normally?
Ye s No
lCheck fuses (No. 19)
lCheck ECU and antenna power
and solenoid valve
ECU terminal
- No. 9 (Ignition)
- No. 6 (Ground)
lCheck battery voltage
lCheck battery wiring
lCheck signal wires between ICU
and antenna
- Immobilizer No.3 wire (0.5Y) =
ICU No. 1 pin (0.75BW)
:
Writing immobilizer code number
- Immobilizer No.4 wire (0.5G) =
ECU No.3 pin (0.75Y)
: Reading immobilizer cod number
lCheck starter wires
lCheck TCU wires (only for 5-
speed automatic transmission)
lCheck starter and TCU
lECU No.2 pin : check normal
signal of the starter 1)
- Engine cranking voltage : 8-15V
lCheck engine speed sensor wires
and replace
lReplace immobilizer antennaNotice
2)
New valve is possible coded either with a
new ICU or an already used ICU. But old
coded valve is only possible coded with a
new ICU.
If transponder and ICU are replaced,
perform programming.
lReplace transponder and ICUlReplace the valve
1. Turn Ign sw ON
2. Turn Ign sw OFF & ON
(To learn the valve correctly it is necessary
to switch on Ignition twice for at least 5
seconds.)2)
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9W-12 IMMOBILIZER SYSTEM
SCHEMATIC AND ROUTING DIAGRAMS
GASOLINE ENGINE (HFM) IMMOBILIZER
Page 1460 of 1463
IMMOBILIZER SYSTEM 9W-13
DIESEL ENGINE IMMOBILIZER