DAEWOO LACETTI 2004 Service Repair Manual

IMMOBILIZER ANTI–THEFT SYSTEM 9T2 – 11
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
IMMOBILIZER SYSTEM
The purpose of the Immobilizer system is to provide addi-
tional theft deterrence to the vehicle in which it is installed
and to prevent it from being stolen or driven by unautho-
rized users.
The verification of the user authorization is done by an igni-
tion key with integrated transponder.
The external LED displays the Immobilizer status and has
an additional theft deterrence function.
To secure the communication, the status is exchanged be-
tween the Immobilizer and the ECM in a 5 byte of encoded
data.
These 5 bytes are composed by a mixture of random data
and two types of fixed code
S a vehicle model identification number : MIN
S a vehicle specific identification : VIN
The MIN is known from the first supply of the system.
The VIN is realized by ICU on the special order from the
key coding (reading of transponder code and storing it as
valid key code in Immobilizer EEPROM).
A different random data is computed at each key transi-
tion.
All the immobilization communication between the ECM
and ICU is made on K–line (K line : Serial data line ’7’).
Due to the learning of the Vehicle specific identification
Number, both ICU and ECM can stay in 3 stable modes
S Virgin mode (VIN not learnt)
S Learnt mode (VIN learnt)
S Neutral mode (for a new VIN learning)
In case of using valid key, the release message commu-
nication with the ECM take place and the LED displays the
Immobilizer status valid key In case of using invalid key,
the ECM disables the fuel injector circuit with coded inter-
vention and sets DTC(Diagnostic Trouble Code)
The above conditions are maintained until the ignition is
switched off.
An ECM without an immobilizer control unit cannot be in-
terchanged for an ECM that is used with an immobilizer
control unit system. The Immobilizer control unit and ECM
must have a matching ID code. ID coding and key coding
are accomplished by using Scanner–100
The Immobilizer system consists of
S a maximum or 5 ignition keys with integrated trans-
ponder
S the toroidal coil (Detection coil) for energizing and
reading the transponder mounted at the ignition
lock.S the Immobilizer control unit(ICU) with :
– power supply
– ignition input circuit
– transponder modulation and demodulation unit
– EEPROM
– driver electronic for the external status LED
– serial data link hardware
S the external status LED for displaying the Immobi-
lizer status
S the serial data link between Immobilizer and ECM
ELECTRONICALLY CODED KEYS
Each valid ignition key has an internal transponder which
is a read /write transponder.
The transponder contains an implementation of a crypto–
algorithm with 96 bits of user configurable s cret–key con-
tained in EEPROM and transmits data to the ICU by mod-
ulating the amplitude of the ele tromagnetic field, and
receives data and commands in a similar way.
DETECTION COIL
The toroidal coil is mounted at the ignition lock in front of
the key barrel.
It is connected to the ICU with a four terminal connector
fixed at the body of the coil.
The length of the connection between coil and Immobilizer
is restricted to 50cm. The correct placement on the ignition
lock and the exact electrical data is very important for the
reading distance of transponder.
he toroidal coil and receiving coil inside the transponder
built a transformer. During the readingprocess the coil in-
duces energy into the transponder. The transponder
charges the field and generates an amplitude modulated
signal with the manchester coded data. This charge of the
field is demodulated inside the Immobilizer.
The Immobilizer contains the coil driver hardware for di-
rect connection of the toroidal coil.
IMMOBILIZER CONTROL UNIT
The function of the Immobilizer System is shared between
the ICU and the ECM.
The task of the Immobilizer Electronic Control unit (ICU)
are:
S Reading of the input information ”ignition ON/OFF”
S Controlling the states LED
S Controlling the transponder read/write process
(modulation, demodulation, decoding, comparison
of the read code with the code of the valid keys).
S Communication with the ECM after ignition ON (re-
ceiving of the ECM–request and transmission of
release message).
S Special functions for calculation and handling of the
VIN–code.
The VIN code is calculated by the Immobilizer using a ran-
dom generator.

9T2 – 12IIMMOBILIZER ANTI–THEFT SYSTEM
DAEWOO V–121 BL4
The VIN code is transmitted from the Immobilizer in the re-
lease message communication only incase of using an au-
thorized key. Without an authorized key it is not possible
to getthe system VIN code.In case of ECM internal state
is in Virgin mode or neutral mode the ECM learns the sys-
tem 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.
S Communication with the DLC–test equipment. Main
functions are the key coding procedure, the VIN–
code handling and the support for system test func-
tions.
S Handling of the software watchdog
Operation
In the active mode of immobilizer (engine OFF, IG key
OFF) the status LED isblinking as mode A. When ignition
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 similar
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 immobi-
lizer control unit to the DLC mode for diagnostics, key cod-
ing and ID coding.
S The status LED is turned off during DLC–mode
S 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 EE-
PROM.
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.
SERIAL DATA LINK
Serial data can be exchanged between a scan tool and the
ECM and the Immobilizer control unit.
ELECTRONIC CONTROL MOUDLE
(ECM)
S 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
communication 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.
S ECM in Learnt mode
In such a state, ECM checks on every commu-
nication, the correct encoding of the ICU.
If the code received is not correct, then the vehicle is im-
mobilized.
The coded 5 bytes of data emitted by ECM are
a mixture of MIN code and random.
The coded 5 bytes of data emitted by ICU are a
mixture of VIN code and random.
S ECM in Neutral mode
This mode is a special intermediate mode, used
for ICU replacement or immobilizer option instal-
lation.
ECM request to ICU the VIN number. As soon
as the ECM receives two correct consecutive
communication 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.
S 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.

IMMOBILIZER ANTI–THEFT SYSTEM 9T2 – 13
DAEWOO V–121 BL4
1. After receiving a response message including the
information ”ICU in learnt mode” and the correct
system VIN–code

the ECM enters the release state, which al-
lows to continue the running of the engine.
2. After receiving a response message including the
information ”ICU in learnt mode” and a wrong sys-
tem VIN–code

the ECM does not send a new request and
enters the blocked state, which causes the ac-
tivation of the immobilization actions of the en-gine.
3. If the ECM doesn’t receive a response message
within a defined time from beginning of the release
time period or the ECM receives a no release an-
swer

the ECM enters the blocked state, which
causes the activation of the immobilization ac-
tions of the engine.
S The inactive state of the Immobilizer (valid key/
invalid key) ends with turning off the ignition.

NUBIRA/LACETTISERVICE NOTICE 0–1
FOREWORD
This manual includes procedure for maintenance, adjustment, service operation and removal
and installation of components.
All information, illustrations and specifications contained in this manual are based on the latest
product information available at the time of manual approval.
The right is reserved to make changes at any time without notice.

0–2 SERVICE NOTICENUBIRA/LACETTI
SECTION 0
SERVICE NOTICE
CONTENTS
1. HOW TO USE THIS MANUAL 0 – 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. SPECIAL INFORMATION 0 – 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. SUPPLEMENTAL RESTRAINT SYSTEM (SRS) 0 – 4. . . . . . . . . . . . . . . . . . . . . . . .

NUBIRA/LACETTISERVICE NOTICE 0–3
1. HOW TO USE THIS MANUAL
.
This manual covers the repairs of NUBIRA/LACETTI
automobile which has been involved in accidents, and it
describes the work related to the replacement of dam-
aged body parts.
Please read through these instructions and familiarize
yourself with them before actually using this manual.
.
Note : Refer to NUBIRA/LACETTI Service Manual for
specifications, wire harness locations, safety stand sup-
port points, etc.
2. SPECIAL INFORMATION
.
Indicates a strong possibility of personal injury or equip-
ment damage if instructions are not followed.
.
Note : Gives helpful information.
.
CAUTION : Detailed descriptions of standard work-
shop procedures, safety principles and service op-
erations are not included. Please note that this manu-
al does contain warnings and cautions against some
specific service methods which could cause PER-
SONAL INJURY, or could damage a vehicle or make
it unsafe. Please understand that these warnings can-
not cover all conceivable ways in which service,
whether or not recommended by GM DAEWOO might
be done or of the possible hazardous consequences
of each conceivable way, not could GM DAEWOO in-
vestigate all such ways. Anyone using service proce-
dures or tools, whether or not recommended by GM
DAEWOO, must satisfy himself thoroughly that nei-
ther personal safety or tools, whether or not recom-
mended by GM DAEWOO, must satisfy himself thor-
oughly that neither personal safety or vehicle safety
will be jeopardized.
.
All information contained in this manual is based on the
latest product information available at the time of print-
ing. We reserve the right to make changes at any time
without notice. No part of this publication may be repro-
duced, stored in retrieval system, or transmitted, in any
form by any means, electronic, mechanical, photocopy-
ing, recording, or otherwise, without the prior written
permission of the publisher. This includes text, figures
and tables.

0–4 SERVICE NOTICENUBIRA/LACETTI
3. SUPPLEMENTAL RESTRAINT
SYSTEM (SRS)
.
The following precautions should be observed when
performing sheet metal work, paint work and repair work
around the locations of the SRS parts.
.
1. SDM(Sensing and Diagnosis Module) are located un-
der the center console ass’y. Avoid strong impact with
ass’y hammer or other tools when repairing the front
side frame and the lower part of the dashboard. Do not
apply heat to these areas with a gas burner, etc.
2. SRS harness is located under the lower part of the
dashboard below the dashboard panel. (SRS harness iscovered with a yellow corrugated tube.) Care should be
taken not to damage the harness when repairing this
area.
3. Do not apply heat of more than 80°C (176°F) when
drying painted surfaces anywhere around the locations
of SRS parts.
4. If strong impact or high temperature needs to be ap-
plied to the areas around the locations of SRS parts, re-
move the part before performing repair work.
5. If any of the SRS related parts is damaged or de-
formed, be sure to replace it.
.
Note : Refer to the Service Manual(Supplemental Re-
straint System) for removal and replacement of SRS re-
lated parts.

BODY REPAIR MANUAL
(NUBIRA/LACETTI)
ISSUED BY
SERVICE ENGINEERING TEAM
GM DAEWOO AUTO & TECHNOLOGY CO., LTD.
199–1 CHONG CHON–DONG, PU PYUNG–GU,
INCHON, KOREA
TELEPHONE : 82–32–520–2737,2064
FACSIMILE : 82–32–520–4808

NUBIRA/LACETTIGENERAL INFORMATION 1–1
SECTION 1
GENERAL INFORMATION
CONTENTS
1. GENERAL INSTRUCTION 1 – 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. IMPORTANT SAFETY NOTICE 1 – 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.BEFORE BEGINNING WORK1–2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2.DURING WORK1–2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. BODY SAFETY 1 – 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. LOADS ON BODY PARTS 1 – 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5. USE OF NEW HIGH–QUALITY MATERIALS 1 – 3. . . . . . . . . . . . . . . . . . . . . . . . . . .
6. CORROSION PROTECTION 1 – 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7. SUMMARY 1 – 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8. ZINC TREATED STEEL PLATE REPAIR 1 – 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9. TECHNICAL ILLUSTRATION 1 – 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10. BODY REPAIR PROCEDURES 1 – 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1–2 GENERAL INFORMATIONNUBIRA/LACETTI
1. GENERAL INSTRUCTION
This publication is designed to help you the body repair
technician with your specialized work. Vehicle bodywork
has changed a great deal over the years. As vehicles
have developed technically, vehicle bodywork has also
had to meet new requirements with design, changes to
reconcile apparently conflicting demands to name just a
few examples:
S strength and safety ; low weight
S spaciousness ; good aerodynamices
S high quality ; low price
.
The durability and ease of repair of the bodywork also
plays an important part.
.
Nowadays, the use of highly automated production
equipment makes it possible to maintain the tightest
tolerances and thus ensure a high level of quality.
.
When bodywork is damaged, the customer rightly ex-
pects it to be expertly repaired to the same quality stan-
dards.
.
At the same time, for his safety, the customer expects
you to have comprehensive knowledge of materials,
measuring and straightening methods, possible distor-
tion, optimum corrosion prevention and much more be-
sides.
.
This publication is designed to help you update your
knowledge and give you an idea of what you require to
rectify moderate or severe accident damage, for your
own safety and for the satisfaction of your customers.
2. IMPORTANT SAFETY NOTICE
2–1. BEFORE BEGINNING WORK
S Disconnect the battery to reduce the possibility of fire
caused by electrical shorts.
S Check for fuel leaks and repair as necessary.
S Remove the fuel tank and/or fuel lines if welding equip-
ment is to be used near the fuel system.
S Before welding, sanding or cutting, protect carpets and
seats with fire–proof covers.
S Follow standard safety practices when using toxic or
flammable liquids.
S Use standard safety equipment when spraying paint,
welding, cutting, sanding or grinding. Standard safety
equipment includes.
S Respirator and filter masks: Designed to filter out toxic
fumes, mist, dust or other airborn particles. Use a respi-
rator or filter mask designed to protect you from the haz-
ards of the particular job; some respirators, for example,
are designed to filter out only dust and airborn particles,
not toxic fumes.
S Safety goggles or glasses: Designed to protect your
eyes from projectiles, dust particles or splashing liquid.
S Gloves: Rubber gloves protect against corrosive chemi-
cals. Welding gloves protect against burns and abra-
sions caused by welding, sanding or grinding.
S Safety shoes: Non–slip soles protect against slipping.
Metal toe inserts protect against falling objects.
S Ear plugs: Protect eardrums from harmful noise levels.
.
2–2. DURING WORK
S Do not smoke while working near the fuel system.
S Deposit gas or solvent–soaked shop towels in an ap-
proved container.
S Brake lining contains asbestos, which can cause cancer.
Do not use an air hose to blow off brake assemblies: use
only an approved vacuum cleaner, and wear an ap-
proved filter mask or respirator.
S Always attach a safety cable when using a hydraulic ram
or a frame straightening table: do not stand in direct line
with the chains used on such equipment.