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Daewoo Nubira. Manual - part 3

IMMOBILIZER ANTI–THEFT SYSTEM 9T – 9

DAEWOO V–121 BL4

Installation Procedure

1. Connect the electrical connectors to the immobilizer

control unit.

2. Install the immobilizer control unit with the bolts.

Tighten

Tighten the immobilizer control unit mounting bolts to
4 N

m (35 lb–in).

3. Install the knee bolster with the bolts.

Tighten

Tighten the knee bolster mounting bolts to 22 N

m (16

lb–in).

4.  Install the instrument panel side cover.
5.  Install the knee bolster trim panel.
6.  Connect the negative battery cable.

Important : After replacing the immobilizer, the keys must
be re–authorized using the key coding procedure. Refer
to”Key Coding Procedure” in this section. Also, the elec-
tronic control module (ECM) identification (ID) code must
be reset. Refer to”ID Code Reprogramming” in this sec-
tion.

9T – 10

IMMOBILIZER ANTI–THEFT SYSTEM

DAEWOO V–121 BL4

GENERAL DESCRIPTION

AND SYSTEM OPERATION

IMMOBILIZER SYSTEM

The purpose of the immobilizer system is to prevent the
vehicle from being stolen or driven by unauthorized users.
Users are authorized by an electronically coded key.

When the ignition is turned ON, the key is tested by the im-
mobilizer system. While the key code is being read by the
immobilizer control unit, the engine can start and run with
any key that will turn the lock cylinder. The key code is read
and compared with key codes that have been stored in the
immobilizer control unit’s memory.

If a valid key is detected, the immobilizer control unit sends
a serial data release message to the powertrain control
module (PCM)/engine control module (ECM). Included in
the release message is an identification (ID) code which
assures that neither the immobilizer control unit nor the
PCM/ECM has been substituted to defeat the system.

If the PCM/ECM does not receive a release message with-
in a specified time, or if the ID codes do not match, the
PCM/ECM performs the following actions:

Disables the fuel injector circuit.

Disables the fuel pump circuit.

Disables the ignition coil.

Sets diagnostic trouble code (DTC) 53.

The above conditions are maintained until the ignition is
turned OFF.

The immobilizer control unit system consists of the follow-
ing components:

Electronically coded keys.

Detection

coil.

Immobilizer control unit.

PCM/ECM.

Instrument cluster indicator.

A data link connector (DLC) to provide serial data
access for a scan tool.

A PCM/ECM for a vehicle without an immobilizer control
unit cannot be interchanged with a PCM/ECM that is used
with an immobilizer control unit system. The immobilizer
control unit and the PCM/ECM must have a matching ID
code. ID coding and key coding are accomplished by using
a scan tool.

ELECTRONICALLY CODED KEYS

Each valid ignition key has an internal transponder which
transmits a unique code. When a key is inserted into the
ignition lock, the transponder is inductively coupled to the
detection coil. The transponder interacts with the detec-
tion coil to generate an amplitude modulated modulated
signal which is conducted from the detection coil to the im-
mobilizer control unit. The immobilizer control unit reads

the radio–frequency signal. A release message is sent to
the powertrain control module (PCM)/engine control mod-
ule (ECM) if the key is authorized.

New keys are coded by using a scan tool. Refer to in this
section.”Key Coding Procedure”

DETECTION COIL

A detection coil is mounted at the ignition lock as an inte-
gral part of the key position trim ring. The wires to and from
the detection coil are connected to the immobilizer. When
the ignition is turned ON, the immobilizer energizes the
detection coil and the coil is coupled inductively to the
transponder in the ignition key. The immobilizer sends a
modulated signal to the detection coil. The signal is
changed by interaction with the internal transponder in the
ignition key. The immobilizer reads the signal from the
detection coil and determines whether the key is autho-
rized.

IMMOBILIZER CONTROL UNIT

The immobilizer control unit is an electronic module in the
instrument panel which verifies the validity of an ignition
key when the ignition is turned ON.

To accomplish its purpose, the immobilizer control unit
performs the following actions:

Learns and stores the codes of valid keys.

Reads the radio frequency input from the ignition
key.

Compares the received code with the codes of the
valid keys.

Sends a release message to the powertrain control
module (PCM)/engine control module (ECM) if a
valid key has been presented.

Calculates and transmits identification (ID) codes
within each release message.

Controls the external relay which interrupts the
starter relay circuit.

Controls the status indicator in the instrument clus-
ter.

Monitors system faults.

Supports system test functions.

Normal Operation

When the ignition is turned ON, the immobilizer control
unit tries to read the key code transmitted by the trans-
ponder in the ignition key.

If a valid key is detected, the immobilizer control unit sends
a release message to the PCM/ECM. The release mes-
sage contains an ID code. Immobilization will be per-
formed by the PCM/ECM if no release message is re-
ceived, or if the ID code in the PCM/ECM does not match
the immobilizer control unit ID code.

If a non–valid key is detected, the release message is not
sent to the PCM/ECM.

When the driver turns the ignition OFF, the immobilizer
control unit switches to the active mode.

IMMOBILIZER ANTI–THEFT SYSTEM 9T – 11

DAEWOO V–121 BL4

Data Link Connector (DLC)

When the ignition is ON, a scan tool can switch the immo-
bilizer control unit to the data link connector (DLC) mode
for the purpose of diagnostics, key coding, or ID coding.

ID Code Handling

One of 65,535 possible ID codes is stored in the immobiliz-
er control unit

’

s memory.

The ID code can be erased by using the scan tools

’

RESET

ID CODE command. When the immobilizer control unit
calculates a new ID code, the PCM/ECM ID code must be
reset to match the immobilizer control unit ID code. To re-
set the ID code, refer to ”ID Code Reprogramming.”

During diagnostic procedures, the ID code can be read for
comparison with the PCM/ECM ID code by using the scan
tool

’

s READ IMMOBILIZER CONTROL UNIT IDCODE

command.

SERIAL DATA LINK

Serial data can be exchanged between a scan tool, the
powertrain control module (PCM)/engine control module
ECM), and the immobilizer control unit.

The scan tool connection is the data link connector (DLC).

POWERTRAIN CONTROL MODULE
(PCM)/ENGINE CONTROL MODULE
(ECM)

When the powertrain control module (PCM)/engine con-

trol module (ECM) detects that the ignition is being turned
ON, the PCM/ECM waits for a release message from the
immobilizer control unit. If a release message is not re-
ceived within a specified time, the PCM/ECM disables the
engine. The engine is also disabled if the identification (ID)
code transmitted by the immobilizer control unit does not
match the code stored in the PCM/ECM

’

s memory. Immo-

bilization remains in effect until the ignition is turned OFF,
or until battery power is removed.

To prevent the vehicle from being driven, the PCM/ECM
applies the following strategy:

The ignition module is put in a bypass mode.

The PCM/ECM will not create an electronic spark
timing (EST) output. Therefore, no spark will be
generated by the ignition coil.

The PCM/ECM will not enable the fuel pump.

The PCM/ECM will not enable the fuel injectors.

The PCM/ECM sets diagnostic trouble code (DTC)
53.

Serial data communication is transmitted on a single wire
between the immobilizer control unit and the PCM/ ECM.

During diagnostic procedures or ID code changing, a scan
tool is added to the communication system.

A PCM/ECM with an immobilizer control unit is not ex-
changeable with a PCM/ECM that does not have an immo-
bilizer control unit.

SECTION : 9T

REMOTE KEYLESS ENTRY AND

PERIMETER/ULTRASONIC ANTI–THEFT SYSTEM

CAUTION : Disconnect the negative battery cable before removing or installing any electrical unit or when a tool
or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help
prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise noted.

TABLE OF CONTENTS

SPECIFICATIONS

9T–1

. . . . . . . . . . . . . . . . . . . . . . . . . .

FASTENER TIGHTENING SPECIFICATIONS

9T–1

SCHEMATIC AND ROUTING DIAGRAMS

9T–2

. . . . .

REMOTE KEYLESS ENTRY AND ANTI–THEFT

SYSTEM (1 OF 2)

9T–2

. . . . . . . . . . . . . . . . . . . . . . .

REMOTE KEYLESS ENTRY AND ANTI–THEFT

SYSTEM (2 OF 2)

9T–3

. . . . . . . . . . . . . . . . . . . . . . .

CONTROL MODULE/RECEIVER CONNECTOR 9T–

WIRING HARNESS CONNECTORS

9T–4

. . . . . . . . .

MAINTENANCE AND REPAIR

9T–5

. . . . . . . . . . . . . . .

ON–VEHICLE SERVICE

9T–5

. . . . . . . . . . . . . . . . . . . . .

CONTROL MODULE/RECEIVER

9T–5

. . . . . . . . . . . .

SIREN

9T–5

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FRONT DOOR TAMPER SWITCH

9T–7

. . . . . . . . . . .

REAR DECK LID TAMPER SWITCH

9T–7

. . . . . . . . .

HOOD OPEN SWITCH

9T–8

. . . . . . . . . . . . . . . . . . . . .

PASSWORD PROGRAMMING

9T–10

. . . . . . . . . . . . .

GENERAL DESCRIPTION AND SYSTEM

OPERATION

9T–11

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

REMOTE KEYLESS ENTRY AND ANTI–THEFT

SYSTEM

9T–11

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

REMOTE LOCKING AND UNLOCKING

9T–11

. . . . . .

SECURITY INDICATOR

9T–11

. . . . . . . . . . . . . . . . . . . .

INTRUSION SENSING

9T–11

. . . . . . . . . . . . . . . . . . . . .

SIREN

9T–11

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VEHICLE LOCATOR

9T–12

. . . . . . . . . . . . . . . . . . . . . .

AUTOLOCKING (SAFETY LOCK)

9T–12

. . . . . . . . . .

CONTROL MODULE/RECEIVER

9T–12

. . . . . . . . . . .

FAULT OR ALARM INDICATION

9T–12

. . . . . . . . . . .

PANIC BUTTON

9T–12

. . . . . . . . . . . . . . . . . . . . . . . . . .

SPECIFICATIONS

FASTENER TIGHTENING SPECIFICATIONS

Application

Lb–Ft

Lb–In

Hood Open Switch Mounting Screw

–

Siren Bracket Mounting Bolt

–

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