Page 2489 of 2643

9T1 – 8IREMOTE KEYLESS ENTRY AND ANTI–THEFT SYSTEM
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
REMOTE KEYLESS ENTRY AND
ANTI–THEFT SYSTEM
The remote keyless entry and anti–theft system can per-
form the following functions:
S Remotely lock and unlock the vehicle doors by
means of a hand–held, high–frequency transmitter.
S Sense intrusion into the vehicle.
S Activate a warning in the event of an intrusion.
S Help the driver find the vehicle in a parking area.
S Automatically re–lock the doors if the door or the
trunk is not opened within 30 seconds after the ve-
hicle has been unlocked by the remote keyless
entry.
S Communicate serial data to a scan tool to help
diagnose system faults.
The remote keyless entry and anti–theft system consists
of the following components:
S Keyless entry and anti–theft control module/receiv-
er.
S Security indicator.
S Trunk open switch (NOTCHBACK).
S Trunk tamper switch (NOTCHBACK).
S Front door tamper switches.
S Door contact switches.
S Central door lock relay.
S Turn signal bulbs.
S Siren.
S Hood open switch.
REMOTE LOCKING AND UNLOCKING
The hand–held transmitter locks and unlocks the vehicle
doors by sending radio waves to the control module/re-
ceiver in the vehicle. The effective range of the transmitter
varies between 5 and 10 meters, (approximately 16 to 32
feet), depending on whether or not objects, such as other
vehicles are blocking the path of the radio waves.
The transmitter has a LOCK button and an UNLOCK but-
ton which only function when the ignition is OFF. Pressing
the UNLOCK button has the following effects:
S The doors are unlocked.
S The turn signal bulbs flash twice.
S The control module is disarmed.
Pressing the LOCK button has the following effects:
S The doors are locked.
S The turn signal bulbs flash once.
S The control module is armed.
The transmitter has a replaceable battery. The battery is
designed to last at least two years before replacement is
necessary.
SECURITY INDICATOR
There is a security indicator on the instrument panel. After
the LOCK button of the transmitter is pressed, the module
is placed in the armed mode, and the security indicator
flashes. The security indicator turns ON for 0.1 second
and OFF for 0.7 second. It then flashes at that frequency
until the control module/receiver is disarmed.
INTRUSION SENSING
The anti–theft function is armed if the transmitter sends
the LOCK message to the control module/receiver when
the ignition is OFF. When the hood, door, or trunk is
opened, the hood open, door contact, or trunk open switch
sends a ”ground” signal to the control module/receiver.
Unless the control module/receiver is disarmed, the siren
will be activated when the ”ground” signal is received from
the trunk open, hood open, or door contact switches.
The following actions disarm the anti–theft system:
S An UNLOCK message is received from the trans-
mitter.
S Key operation is detected by the tamper switches.
(The tamper switches are operated by the lock cyl-
inders in the front doors and trunk.)
The alarm will also be activated if the control module/re-
ceiver detects voltage from the ignition before either of the
following conditions occur:
S An UNLOCK message is received from the trans-
mitter.
S Key operation is indicated by the tamper switches.
SIREN (GENERAL ONLY)
The remote keyless entry system is armed when the
LOCK message is received from the transmitter when the
ignition is OFF. When the system is armed, it will activate
the siren and flash the turn signals for 28 seconds if any
of the following conditions occur:
S Close all the windows.
S Turn the ignition key to LOCK and remove the key.
S Have all passengers get out of the vehicle.
S Close all doors, the hood and the turnk lid.
S The control module/receiver detects ignition voltage
while the system is armed.
The siren will not operate if any of the following conditions
occur after the system has been armed:
S The door is opened with the key.
S The trunk is opened with the key.
S The UNLOCK or LOCK button on the remote trans-
mitter is pressed within 2 seconds after the siren is
activated.
VEHICLE LOCATOR
The remote keyless entry system assists the driver in lo-
cating the vehicle. When the vehicle is unlocked with the
remote control, the turn signals flash twice to indicate the
location of the vehicle. The duration of the flashes and the
Page 2490 of 2643

REMOTE KEYLESS ENTRY AND ANTI–THEFT SYSTEM 9T1 – 9
DAEWOO V–121 BL4
length of time between flashes is used to indicate certain
vehicle conditions. Refer to ”Fault or Alarm Indication” in
this section.
AUTOLOCKING (SAFETY LOCK)
The remote keyless entry system features an autolocking
feature. If the doors are unlocked with the remote transmit-
ter when the control module/receiver is in the armed
mode, the doors are automatically re–locked after 30 sec-
onds unless any of the following events occur:
S A door is opened.
S The ignition is ON.
S The trunk is opened.
S The hood is opened.
CONTROL MODULE/RECEIVER
The remote keyless entry control module/receiver is con-
tained in the floor console. The module/receiver pro-
cesses signals from the remote transmitter and various
switches. It activates the alarm if an intrusion is detected.
The control module/receiver also has a self–diagnostic
function which will display trouble codes. In order to dis-
play trouble codes, a scan tool must be connected to the
data link connector (DLC).
The control module/receiver will not communicate with
transmitters from other vehicles because there are over
four billion possible electronic password combinations. Itis highly unlikely that any transmitters will use the same
password. The control module/receiver has an attached
antenna to detect signals from the transmitter.
FAULT OR ALARM INDICATION
When the UNLOCK button on the remote transmitter is
pressed, the control module/receiver will flash the parking
lights to indicate information about the remote keyless
entry and anti–theft system.
Normal Condition: If there has not been an intrusion, and
no fault has been detected, the control module/receiver
will signal a normal condition when the UNLOCK button is
pressed. The parking lights will flash twice for 0.5 second,
with a 0.5 second pause between flashes.
Fault Indication: If there is a fault in the remote keyless
entry and anti–theft system, the control module/receiver
will signal the fault when the UNLOCK button is pressed.
The parking lights will flash twice for 1 second, with a 0.5
second pause between flashes.
Alarm Indication: If there has been an intrusion since the
last time the LOCK button was pressed, the control mod-
ule/receiver will signal that there has been an intrusion
when the UNLOCK button is pressed. The parking lights
will flash twice for 0.5 second, with a 1.5 second pause be-
tween flashes.
Alarm and fault information will be erased the next time the
transmitter arms the control module/receiver by transmit-
ting a LOCK message.
Page 2491 of 2643

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. . . . . . . . . .
Page 2492 of 2643
9T2 – 2IIMMOBILIZER ANTI–THEFT SYSTEM
DAEWOO V–121 BL4
SCHEMATIC AND ROUTING DIAGRAMS
IMMOBILIZER ANTI–THEFT SYSTEM
Page 2493 of 2643

IMMOBILIZER ANTI–THEFT SYSTEM 9T2 – 3
DAEWOO V–121 BL4
DIAGNOSTIC INFORMATION AND
PROCEDURES
IMMOBILIZER SYSTEM (MR–140,
HV–240, SIRIUS D4)
The immobilizer anti–theft system requires diagnosis
when it is not possible to start the engine. If the no–start
condition occurs because of the immobilizer system, a
diagnostic trouble code (P) 1626, 1628, 1629, 1631 should
be set.
The immobilizer control unit monitors the detection and
the reading of the ignition key. The self–test capacity is lim-
ited to those functions. Faults are communicated to a scan
tool during diagnosis, but they are not stored in the immo-
bilizer control unit’s memory.Unauthorized use of a scan tool could be a method of de-
feating the immobilizer anti–theft system, so certain scan
tool procedures require the use of a password. The follow-
ing functions are password protected:
S Coding of an additional key.
S Deleting all key codes.
The following functions do not require a password:
S Reading an ignition key to determine if the trans-
ponder is working or if a key is authorized.
S Reading the immobilizer ID code to verify that it
matches the ECM ID code.
Page 2494 of 2643

9T2 – 4IIMMOBILIZER ANTI–THEFT SYSTEM
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1626 (MR–140,
HV–240), P1628 (SIRIUS)
ECM IMMOBILIZER ERROR (NO SUCCESSFUL
COMMUNICATION)
Circuit Description
When the ignition is turned ON, the key is tested by the im-
mobilizer anti–theft 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 memory of the immobilizer control unit. If a
valid key is detected, the immobilizer control unit sends a
serial data release message to the electronic control mod-
ule (ECM). Included in the release message is an identifi-
cation (ID) code which assures that neither the immobiliz-
er control unit nor the ECM has been substituted to defeatthe system. If the ECM receives an invalid release mes-
sage, the ECM performs the following actions:
S Disables the fuel injector circuit.
P1626, 1628 Will Set When
S The ECM does not receive the signal from the im-
mobilizer control module within 1.260 seconds after
the ignition is turned on.
S The above conditions are maintained until the igni-
tion is switched OFF.
P1626, 1628 Will Clear When
S The ignition switch is turned OFF or the scan tool
TROUBLE CODE CLEAR command is issued.
Page 2495 of 2643

IMMOBILIZER ANTI–THEFT SYSTEM 9T2 – 5
DAEWOO V–121 BL4
P1626, 1628 – ECM Immobilizer Error
(No Successful Communication)
StepActionValue(s)YesNo
1Connect the scan tool using the following procedure:
1. Insert the cartridge into the scan tool.
2. Turn the ignition switch to the OFF position.
3. Connect the scan tool to the data link connec-
tor (DLC).
4. Connect the scan tool’s power cord to the cigar
lighter socket.
5. Select immobilizer mode on the scan tool.
6. Turn the ignition ON, but do not start the en-
gine.
Is communication established between the scan tool
and the immobilizer control unit?–Go to Step 2Go to ”Commu-
nication Be-
tween Immobi-
lizer and Test
Equipment”
2Read the IMMO & ECM ID CODE message that was
displayed after requesting DIAGNOSIS.
Did the message differ from normal message?
Normal Message –
ECM MODE: LEARNT
IMMO. MODE: LEARNT
VIN CODE: SAME–Go to ”Identifi-
cation (ID)
Code Repro–
gramming”Go to Step 3
3Check for an open serial data wire between the im-
mobilizer control unit and the ECM.
Was the circuit open?–Go to Step 4Go to Step 5
4Repair the open serial data wire between the ECM
and the immobilizer control unit.
Is the repair complete?–System OK–
51. Replace the immobilizer.
2. Reprogram the identification (ID) code. Refer
to ”Identification (ID) Code Reprogramming” in
this section.
Is the repair complete?–System OKGo to Step 6
61. Replace the ECM.
2. Turn the ignition ON, OFF for more than 4 sec-
onds.
3. Turn the ignition ON.
Is the repair complete?–System OK–
Page 2496 of 2643

9T2 – 6IIMMOBILIZER ANTI–THEFT SYSTEM
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1631 (MR–140,
HV–240), P1629 (SIRIUS D4)
ECM IMMOBILIZER ERROR (INCORRECT ANSWER)
Circuit Description
When the ignition is turned ON, the key is tested by the im-
mobilizer anti–theft 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 memory of the immobilizer control unit. If a
valid key is detected, the immobilizer control unit sends a
serial data release message to the electronic control mod-
ule (ECM). Included in the release message is an identifi-
cation (ID) code which assures that neither the immobiliz-er control unit nor the ECM has been substituted to defeat
the system. If the ECM receives an invalid release mes-
sage, the ECM performs the following actions:
S Disables the fuel injector circuit.
P1631, 1629 Will Set When
S The ECM receives an incorrect release message
from the immobilizer control unit more than five
times.
P1631, 1629 Will Clear When
S The ignition switch is turned OFF or the scan tool
TROUBLE CODE CLEAR command is issued.