2004 DAEWOO NUBIRA CODED KEY

1F – 338IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1629
IMMOBILIZER WRONG COMPUTATION
Circuit Description
When the ignition switch is turned to ON, the key tested
by immobilizer anti–theft system. While the key code is be-
ing read by immobilizer control unit or integrated anti–theft
control unit, the engine can start 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 memory of the
immobilizer control unit. If a valid key is detected, the im-
mobilizer control unit sends a serial data release message
to the Engine Control Module (ECM). Included in the re-
lease message is an identification (ID) code which as-
sures that neither the immobilizer control unit nor the ECM
have been substituted to defeat the system. If the ECM re-
ceives an invalid release message, the ECM performs the
following action:
S Disable the fuel injector circuit.
S Disable the fuel pump circuit.
S Disable the ignition coil.A Diagnostic Trouble Code (DTC) will stored if detect com-
munication link failure between the ECM and immobilizer
control unit.
Conditions for Setting the DTC
S Wrong coded value from ICU.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.

ENGINE CONTROLS 1F – 629
DAEWOO V–121 BL4
tentially interfere with the operation of the Exhaust Gas
Recirculation (EGR) valve and thereby turn on the MIL.
Small leaks in the exhaust system near the post catalyst
oxygen sensor can also cause the MIL to turn on.
Aftermarket electronics, such as cellular phones, stereos,
and anti–theft devices, may radiate electromagnetic inter-
ference (EMI) into the control system if they are improperly
installed. This may cause a false sensor reading and turn
on the MIL.
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain–soaked, it can temporarily
cause engine misfire and turn on the MIL.
Refueling
A new EOBD diagnostic checks the integrity of the entire
Evaporative (EVAP) Emission system. If the vehicle is re-
started after refueling and the fuel cap is not secured cor-
rectly, the on–board diagnostic system will sense this as
a system fault, turn on the MIL, and set DTC P0440.
Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 2 to 3 miles of driving. This type of operation
contributes to the fuel fouling of the spark plugs and will
turn on the MIL with a set DTC P0300.
Poor Vehicle Maintenance
The sensitivity of EOBD diagnostics will cause the MIL to
turn on if the vehicle is not maintained properly. Restricted
air filters, fuel filters, and crankcase deposits due to lack
of oil changes or improper oil viscosity can trigger actual
vehicle faults that were not previously monitored prior to
EOBD. Poor vehicle maintenance can not be classified as
a ”non–vehicle fault,” but with the sensitivity of EOBD
diagnostics, vehicle maintenance schedules must be
more closely followed.
Severe Vibration
The Misfire diagnostic measures small changes in the
rotational speed of the crankshaft. Severe driveline vibra-
tions in the vehicle, such as caused by an excessive
amount of mud on the wheels, can have the same effect
on crankshaft speed as misfire and, therefore, may set
DTC P0300.
Related System Faults
Many of the EOBD system diagnostics will not run if the
engine controlmodule (ECM) detects a fault on a related
system or component. One example would be that if the
ECM detected a Misfire fault, the diagnostics on the cata-
lytic converter would be suspended until the Misfire fault
was repaired. If the Misfire fault is severe enough, the cat-
alytic converter can be damaged due to overheating andwill never set a Catalyst DTC until the Misfire fault is re-
paired and the Catalyst diagnostic is allowed to run to
completion. If this happens, the customer may have to
make two trips to the dealership in order to repair the ve-
hicle.
SERIAL DATA COMMUNICATIONS
Class II Serial Data Communications
Government regulations require that all vehicle manufac-
turers establish a common communication system. This
vehicle utilizes the ”Class II” communication system. Each
bit of information can have one of two lengths: long or
short. This allows vehicle wiring to be reduced by transmit-
ting and receiving multiple signals over a single wire. The
messages carried on Class II data streams are also priori-
tized. If two messages attempt to establish communica-
tions on the data line at the same time, only the message
with higher priority will continue. The device with the lower
priority message must wait. Themost significant result of
this regulation is that it provides scan tool manufacturers
with the capability to access data from any make or model
vehicle that is sold.
The data displayed on the other scan tool will appear the
same, with some exceptions. Some scan tools will only be
able to display certain vehicle parameters as values that
are a coded representation of the true or actual value. On
this vehicle the scan tool displays the actual values for ve-
hicle parameters. It will not be necessary to perform any
conversions from coded values to actual values.
ON–BOARD DIAGNOSTIC (EOBD)
On–Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:
S The diagnostic test has been completed since the
last ignition cycle.
S The diagnostic test has passed during the current
ignition cycle.
S The fault identified by the diagnostic test is not cur-
rently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:
S The diagnostic test has been completed since the
last ignition cycle.
S The fault identified by the diagnostic test is current-
ly active.
S The fault has been active during this ignition cycle.
S The operating conditions at the time of the failure.
Remember, a fuel trim Diagnostic Trouble Code (DTC)
may be triggered by a list of vehicle faults. Make use of all
information available (other DTCs stored, rich or lean con-
dition, etc.) when diagnosing a fuel trim fault.

SECTION : 9T2
IMMOBILIZER 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
SCHEMATIC AND ROUTING DIAGRAMS9T2–2 . . . .
Immobilizer Anti–Theft System 9T2–2. . . . . . . . . . . . .
DIAGNOSTIC INFORMATION AND
PROCEDURES9T2–3 . . . . . . . . . . . . . . . . . . . . . . . . . .
Immobilizer System
(MR–140, HV–240, SIRIUS D4) 9T2–3. . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1626 (MR–140,
HV–240), P1628 (SIRIUS) 9T2–4. . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1631 (MR–140,
HV–240), P1629 (SIRIUS D4) 9T2–6. . . . . . . . . . . .
Key Status Errors
(MR–140, HV–240, SIRIUS D4) 9T2–8. . . . . . . . . . .
Communication Between Immobilizer Control Unit and
Test Equipment
(MR–140, HV–240, SIRIUS D4) 9T2–8. . . . . . . . . . . MAINTENANCE AND REPAIR9T2–9 . . . . . . . . . . . . . .
ON–VEHICLE SERVICE 9T2–9. . . . . . . . . . . . . . . . . . . .
Key Coding Procedure 9T2–9. . . . . . . . . . . . . . . . . . . .
ID Code Reprogramming 9T2–9. . . . . . . . . . . . . . . . . .
Transponder 9T2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Immobilizer Control Unit 9T2–9. . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION9T2–11 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Immobilizer System 9T2–11. . . . . . . . . . . . . . . . . . . . . .
Electronically Coded Keys 9T2–11. . . . . . . . . . . . . . . .
Detection Coil 9T2–11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Immobilizer Control Unit 9T2–11. . . . . . . . . . . . . . . . . .
Serial Data Link 9T2–12. . . . . . . . . . . . . . . . . . . . . . . . .
Electronic Control Moudle (ECM) 9T2–12. . . . . . . . . .

9T2 – 8IIMMOBILIZER ANTI–THEFT SYSTEM
DAEWOO V–121 BL4
KEY STATUS ERRORS (MR–140,
HV–240, SIRIUS D4)
The following KEY STATUS messages may be shown on
the scan tool after commanding FIRST KEY CODING and
KEY ADD:
S IGNITION OFF STATUS. This message informs
the technician that the ignition is off during the key
coding process. Turn the ignition ON during key
coding, but do not start the engine.
S KEY IS OCCUPIED. Only five keys may be coded.
If a new key is desired, the previous key codes
must be deleted. Up to five keys may then be au-
thorized.
S ALREADY AUTHORIZED. Key coding is being at-
tempted with a key that is already authorized.
S ERROR NO. A3, A4, A5. There is no communica-
tion between the transponder in the ignition key and
the detection coil. Follow the steps below to diag-
nose the problem:
1) Try a different key. If a different key works, the
problem was in the original key.
2) If trying a different key resulted in the same
error message, replace the detection coil.
S INVALID KEY. The communication between the
immobilizer control unit and the key transponder
has not validated the key. Follow the steps below to
diagnose the problem:
1) Code the key. Refer to ”Key Coding Procedure”
in this section.
2) If the same message is received after key cod-
ing, check the connection of the detection coil.
3) If the detection coil is okay, replace the immo-
bilizer. Refer to ”Immobilizer Control Unit” in
this section.S NO TRANSPONDER DETECTED. The fault may
be in ignition key transponder, the detection coil, or
the Immobilizer. Follow the steps below to diagnose
the problem:
1) Try a different key. If a different key works, the
problem was in the original key.
2) If trying a different key resulted in the same
error message, check the connection of the
detection coil.
3) If the connection of the detection coil is okay,
disconnect the detection coil and use an ohm-
meter to check for an open detection coil.
4) If the detection coil was not open, replace the
immobilizer control unit. Refer to ”Immobilizer
Control Unit” in this section.
COMMUNICATION BETWEEN
IMMOBILIZER CONTROL UNIT AND
TEST EQUIPMENT (MR–140, HV–240,
SIRIUS D4)
1. Connect the test equipment as described in the
Scan Tool Equipment Manual.
2. If communication between the scan tool and the
test equipment was unsuccessful, wait 30 seconds
and try again.
3. If communication was not successful on the second
try, turn the ignition OFF and check the wire and
connectors between the immobilizer control unit
terminal 7 and the data link connector (DLC) termi-
nal 7.
4. If the wire and connectors between the DLC and
the immobilizer control unit are okay, replace the
immobilizer control unit. Refer to ”Immobilizer Con-
trol Unit” in this section.

IMMOBILIZER ANTI–THEFT SYSTEM 9T2 – 9
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
KEY CODING PROCEDURE
1. Install the immobilizer control unit cartridge in the
scan tool.
2. Turn the ignition off
3. Connect the scan tool
4. Turn the ignition on with the key to be coded
5. Enter the four–digit password that enables service
personnel to use the scan tool for key coding.
6. Use the scan tool command.
7. Verify that the key coding was successful by start-
ing the engine with each of the authorized keys.
ID CODE REPROGRAMMING
Reprogram the identification (ID) code in the following si-
tuations:
S An immobilizer control unit has been replaced.
S An electronic control module (ECM) has been re-
placed.
If a valid key has been lost, refer to ”Key Coding Proce-
dure” in this section.
TRANSPONDER
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 secret–key con-
tained in EEPROM and transmits data to the ICU by mod-
ulating the amplitude of the electromagnetic field, and
receives data and commands in a similar way.
IMMOBILIZER CONTROL UNIT
Removal Procedure
1. Remove the imstrument panel lower cover.

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.