Real DAEWOO LACETTI 2004 Service Repair Manual

1F – 634IENGINE CONTROLS
DAEWOO V–121 BL4
A rough road sensor, or G sensor, works together with the
misfire detection system. The G sensor produces a volt-
age that varies along with the intensity of road vibrations.
When the ECM detects a rough road, the misfire detection
system is temporarily disabled.
Misfire Counters
Whenever a cylinder misfires, the misfire diagnostic
counts the misfire and notes the crankshaft position at the
time the misfire occurred. These ”misfire counters” are ba-
sically a file on each engine cylinder. A current and a histo-
ry misfire counter are maintained for each cylinder. The
misfire current counters (Misfire Cur #1–4) indicate the
number of firing events out of the last 200 cylinder firing
events which were misfires. The misfire current counter
will display real time data without a misfire Diagnostic
Trouble Code (DTC) stored. The misfire history counters
(Misfire Hist #1–4) indicate the total number of cylinder fir-
ing events which were misfires. The misfire history count-
ers will display 0 until the misfire iagnostic has failed and
a DTC P0300 is set. Once the misfire DTC P0300 is set,
the misfire history counters will be updated every 200 cyl-
inder firing events. A misfire counter is maintained for each
cylinder.
If the misfire diagnostic reports a failure, the diagnostic
executive reviews all of the misfire counters before report-
ing a DTC. This way, the diagnostic executive reports the
most current information.
When crankshaft rotation is erratic, a misfire condition will
be detected. Because of this erratic condition, the data
that is collected by the diagnostic can sometimes incor-
rectly identify which cylinder is misfiring.
Use diagnostic equipment to monitor misfire counter data
on On–Board Diagnostic (EOBD) compliant vehicles.
Knowing which specific cylinder(s) misfired can lead to the
root cause, even when dealing with amultiple cylinder mis-
fire. Using the information in the misfire counters, identify
which cylinders are misfiring. If the counters indicate cylin-
ders numbers 1 and 4 misfired, look for a circuit or compo-
nent common to both cylinders number 1 and 4.
The misfire diagnostic may indicate a fault due to a tempo-
rary fault not necessarily caused by a vehicle emission
system malfunction. Examples include the following
items:
S Contaminated fuel.S Low fuel.
S Fuel–fouled spark plugs.
S Basic engine fault.
Fuel Trim System Monitor Diagnostic
Operation
This system monitors the averages of short–term and
long–term fuel trim values. If these fuel trim values stay at
their limits for a calibrated period of time, a malfunction is
indicated. The fuel trim diagnostic compares the averages
of short–term fuel trim values and long–term fuel trim val-
ues to rich and lean thresholds. If either value is within the
thresholds, a pass is recorded. If both values are outside
their thresholds, a rich or lean DTC will be recorded.
The fuel trim system diagnostic also conducts an intrusive
test. This test determines if a rich condition is being
caused by excessive fuel vapor from the Evaporative
(EVAP) Emission canister. In order to meet EOBD require-
ments, the control module uses weighted fuel trim cells to
determine the need to set a fuel trim DTC. A fuel trim DTC
can only be set if fuel trim counts in the weighted fuel trim
cells exceed specifications. This means that the vehicle
could have a fuel trim problem which is causing a problem
under certain conditions (i.e., engine idle high due to a
small vacuum leak or rough idle due to a large vacuum
leak) while it operates fine at other times. No fuel trim DTC
would set (although an engine idle speed DTC or HO2S2
DTC may set). Use a scan tool to observe fuel trim counts
while the problem is occurring.
A fuel trim DTC may be triggered by a number of vehicle
faults. Make use of all information available (other DTCs
stored, rich or lean condition, etc.) when diagnosing a fuel
trim fault.
Fuel Trim Cell Diagnostic Weights
No fuel trim DTC will set regardless of the fuel trim counts
in cell 0 unless the fuel trim counts in the weighted cells are
also outside specifications. This means that the vehicle
could have a fuel trim problem which is causing a problem
under certain conditions (i.e. engine idle high due to a
small vacuum leak or rough due to a large vacuum leak)
while it operates fine at other times. No fuel trim DTC
would set (although an engine idle speed DTC or HO2S2
DTC may set). Use a scan tool to observe fuel trim counts
while the problem is occurring.

5A1 – 90IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DTC P0710 – Transmission Fluid Temperature Sensor Circuit
Malfunction
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the check completed?–Go to Step 2Go to ”On–
Board Diagnos-
tic System
Check”
21. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.
3. Record then clear DTC(s) and turn the ignition
OFF, then turn the ignition ON.
4. Select TFT on the scan tool.
5. Drive the vehicle and observe the scan tool for
either of the flowing conditions:
6. The TFT does not change more than 1.5°C
(34.7°F) in 80 seconds since start–up.
7. The TFT changes more than 20°C (68°F) with-
in 7 seconds (unrealistic change).
Did either of the fail conditions occur?–Go to Step 3Go to ”Diag-
nostic Aids”
31. Turn the ignition OFF.
2. Disconnect the transaxle wiring connector.
3. Measure the resistance between terminals 9
and 4 of the transaxle wiring connector.
Is the resistance within the values shown?TFT 25°C
990 ΩGo to Step 7Go to Step 4
41. Remove the oil pan.
2. Disconnect the wiring connector of the trans-
axle fluid temperature sensor.
3. Inspect the automatic transaxle wiring harness
for an intermittent short or open.
Was a problem found?–Go to Step 5Go to Step 6
5Replace the automatic transaxle wiring harness.
Is the replacement complete?–System OK–
6Replace the TFT sensor.
Is the action complete?–System OK–
71. Disconnect the automatic transaxle wiring con-
nector and disconnect the wiring connector of
the TCM(transaxle control module).
2. Measure the resistance between terminal 4 of
the transaxle wiring connector and terminal B1
of the TCM wiring connector.
3. Measure the resistance between terminal 9 of
the transaxle wiring connector and terminal A4
of the TCM wiring connector.
Is the resistance within the values shown?0ΩGo to Step 9Go to Step 8
81. Inspect the automatic transaxle wiring harness
for an intermittent short to ground or open con-
dition.
2. Inspect the automatic TFT sensor wiring har-
ness for an intermittent short to ground or open
condition.
3. Repair the circuits if necessary.
Is the repair complete?–System OK–

STEERING WHEEL AND COLUMN 6E – 3
DAEWOO V–121 BL4
High Lock Effort
ChecksAction
Check the lock cylinder for damage.Replace the lock cylinder.
Check the ignition switch for lack of free movement.Lubricate the ignition switch.
Check for extreme misalignment of the housing to the cov-
er.Realign the cover on the housing. Replace the cover as
needed.
Check for a bent ignition switch mounting bracket.Replace the ignition switch mounting bracket.
Key Cannot Be Removed in the LOCK Position
ChecksAction
Check to see that the ignition switch is set correctly.Reset the ignition switch.
Check the lock cylinder for damage.Replace the lock cylinder.
Check the fuse F17 from the I/P fuse block.Replace the fuse F17
Check for an open or short in the circuit between terminal
2 of key interlock solenoid and the I/P fuse block.Replace the fuse F17
Select the gear shift lever to ”P” position.
Check the resistance between the terminal 2 and 1 of the
”P” position switch.Replace the ”P” position switch.
Check for an open or short in the circuit between the
ground G202 and terminal 1 of the key interlock unit.Replace the open or short from the circuit.
Turn the ignition ON.
Select the gear shift lever to ”P” position.
Check the resistance between the terminal 1 and 2 of the
key interlock solenoid.Replace the key interlock solenoid.

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.