YH4
GRAND
VITARA
GENERAL INFORMATION 0A-9
When disconnecting vacuum hoses, attach a tag describing
the correct installation positions so that the hoses can be re-
installed correctly.
After servicing fuel, oil, coolant, vacuum, exhaust or brake
systems, check all lines related to the system for leaks.
For vehicles equipped with fuel injection systems, never dis-
connect the fuel line between the fuel pump and injector
without first releasing the fuel pressure, or fuel can be
sprayed out under pressure.
PRECAUTIONS FOR CATALYTIC CONVERTER
For vehicles equipped with a catalytic converter, use only un-
leaded gasoline and be careful not to let a large amount of un-
burned gasoline enter the converter or it can be damaged.
± Conduct a spark jump test only when necessary, make it as
short as possible, and do not open the throttle.
± Conduct engine compression checks within the shortest
possible time.
± Avoid situations which can result in engine misfire (e.g.
starting the engine when the fuel tank is nearly empty).
YH4
GRAND
VITARA
1. Coil antenna
2. Ignition key
3. Immobilizer control module
4. Data link connector (DLC)
5. Immobilizer diagnostic coupler Ignition key
Transponder
code
Immobilizer
Control
ModuleECM/
PCM
8G-2 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
GENERAL DESCRIPTION
The immobilizer control system designed to prevent vehicle burglar consists of following components.
Engine control module (ECM) / Powertrain control module (PCM)
Immobilizer control module
Ignition key (with built-in transponder)
Coil antenna
Operation of this system is as follows.
(1) Each ignition key has its own code (Transponder code) stored in memory. When the ignition switch is turned
ON, Immobilizer Control Module tries to read the Transponder code through the coil antenna installed to the
steering lock assembly.
(2) Immobilizer Control Module compares the Transponder code read in (1) and that registered in Immobilizer Con-
trol Module and checks if they match.
(3) When it is confirmed that two Transponder codes match each other as described above, Immobilizer Control
Module and ECM / PCM check if ECM/Immobilizer Control Module codes registered in them respectively match.
(4) Only when it is confirmed that ECM/Immobilizer Control Module codes match, the engine starts running. If
Transponder codes in Step (2) or ECM/Immobilizer Control Module codes in Step (3) do not match, ECM / PCM
will stop operation of the injector and ignition of spark plug.
