automatic transaxle DAEWOO NUBIRA 2004 Service Owner's Manual

1F – 82IENGINE CONTROLS
DAEWOO V–121 BL4
IDLE AIR CONTROL SYSTEM CHECK (1.8L DOHC)
Circuit Description
The Engine Control Module (ECM) controls the engine idle
speed with the Idle Air Control (IAC) valve. To increase the
idle speed, the ECM pulls the IAC pintle away from its seat,
allowing more air to pass by the throttle body. To decrease
the idle speed, it extends the IAC valve pintle toward its
seat, reducing bypass air flow. A scan tool will read the
ECM commands to the IAC valve in counts. The higher
counts indicate more air bypass (higher idle). The lower
counts indicate less air is allowed to bypass (lower idle).
Diagnostic Aids
If the idle is too high, stop the engine. Fully extend the Idle
Air Control (IAC) valve with a IAC driver. Start the engine.
If the idle speed is above 800 rpm, locate and repair the
vacuum leak. Also, check for a binding throttle plate or
throttle linkage or an incorrect base idle setting.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
2. The IAC valve is extended and retracted by the IAC
driver. IAC valve movement is verified by an engine
speed change. If no change in engine speed oc-
curs, the valve can be removed from the throttle
body and tested. Connect the IAC driver to the re-
moved IAC valve and turn the ignition ON. Do not
start the engine.5. This step checks the quality of the IAC valve move-
ment in Step 2. Fully extending the IAC valve may
cause an engine stall. This may be normal.
6. Steps 2 and 5 verify proper IAC valve operation.
This step checks the IAC circuit for a wiring or ECM
fault.
Idle Air Control Valve Reset Procedure
Whenever the battery cable or the Engine Control Module
(ECM) connector or the ECM fuse Ef11 is disconnected or
replaced, the following idle learn procedure must be per-
formed:
1. Turn the ignition ON for 5 seconds.
2. Turn the ignition OFF for 10 seconds.
3. Turn the ignition ON for 5 seconds.
4. Start the engine in park/neutral.
5. Allow the engine to run until the engine coolant is
above 185°F (85°C).
6. Turn the A/C ON for 10 seconds, if equipped.
7. Turn the A/C OFF for 10 seconds, if equipped.
8. If the vehicle is equipped with an automatic trans-
axle, apply the parking brake. While pressing the
brake pedal, place the transaxle in D (drive).
9. Turn the A/C ON for 10 seconds, if equipped.
10. Turn the A/C OFF for 10 seconds, if equipped.
11. Turn the ignition OFF. The idle learn procedure is
complete.

1F – 468IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0401
EXHAUST GAS RECIRCULATION INSUFFICIENT FLOW
Circuit Description
An Exhaust Gas Recirculation (EGR) system is used to
lower Nitrogen Oxide (NOx) emission levels caused by
high combustion temperatures. It accomplishes this by
feeding small amounts of exhaust gases back into the
combustion chamber. When the air/fuel mixture is diluted
with the exhaust gases, combustion temperatures are re-
duced
A linear EGR valve is used on this system. The linear EGR
valve is designed to accurately supply exhaust gases to
the engine without the use of intake manifold vacuum. The
valve controls exhaust flow going into the intake manifold
from the exhaust manifold through an orifice with an En-
gine Control Module (ECM) controlled pintle. The ECM
controls the pintle position using inputs from the Throttle
Position (TP) and Manifold Absolute Pressure (MAP) sen-
sors. The ECM then commands the EGR valve to operate
when necessary by controlling an ignition signal through
the ECM. This can be monitored on a scan tool as the De-
sired EGR Position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EGR valve, a voltage signal representing the
EGR valve pintle position is sent to the ECM. This feed-
back signal can also be monitored on a scan tool and is the
actual position of the EGR pintle. The Actual EGR Position
should always be near the commanded or Desired EGR
Position.
This diagnostic will determine if there is a reduction in EGR
flow.
Conditions for Setting the DTC
S DTCs P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0201, P0202, P0203, P0204,
P0351, P0352, P0402, P0404, P1404, P0405,
P0406 and P0502 are not set.
S Test in Decel Fuel Cutoff (DFCO) mode.
S Barometric Pressure (BARO) is greater than 72
kPa (10.4 psi).
S Vehicle speed is greater than 18 km/h (11.2
mph).
S A/C clutch/transmission clutch are unchanged.
S Rpm is between 1400 and 3000 for manual
transaxle.
S Rpm is between 1300 and 2900 for automatic
transaxle.
S Compensated MAP is with 10.3 to 32 kpa (1.5 to
4.6 psi) range.
S Start test
S Throttle position (TP) sensor is less then 1%.
S EGR is less than 1%.
S Change in MAP is less than 1.0 kpa (0.15 psi)Note : Test will be aborted when:
S Change in vehicle speed is greater than 5km/h (3.1
mph).
S Rpm is increased more than 75.
S EGR opened less than 90% commanded position.
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 set as Failure Records data only.
This information will not be stored in the Freeze
Frame data.
S A history Diagnostic Trouble Code (DTC) is stored.
S EGR is disabled.
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.
Diagnostic Aids
The EGR Decel Filter value can be a great aid in determin-
ing if a problem exists and to verify repairs. The EGR De-
cel Filter is an average of the difference in the expected
MAP change and the actual MAP change caused by open-
ing the EGR valve during a deceleration, and is used to de-
termine when the MIL is illuminated. By driving the vehicle
up to approximately 97 km/h (60 mph) and decelerating to
32 km/h (20 mph), it can be determined if the EGR system
is OK, partially restricted, or fully restricted.
A more negative number (less than –3) indicates that the
system is working normally, whereas a positive number in-
dicates that the system is being restricted and that the ex-
pected amount of EGR flow is was not seen. A number
that falls between negative 3 and positive 2 indicates that
the system is partially restricted but not restricted enough
to cause an emissions impact.
The EGR Decel Filter value should always be at –3 or low-
er. If the EGR Decel Filter number becomes more positive
(towards 0 or more), then the EGR system is becoming re-
stricted. Look for possible damage to the EGR pipe or for
a restriction caused by carbon deposits in the EGR pas-
sages or on the EGR valve.
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This

1F – 484IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0420
CATALYST OXYGEN SENSOR LOW EFFICIENCY
Circuit Description
In order to control exhaust emissions of Hydrocarbons
(HC), Carbon Monoxide (CO) and Nitrogen Oxide (NOx),
a Three–Way Catalytic Converter (TWC) is used. The cat-
alyst within the converter promotes a chemical reaction
which oxidizes the HC and CO present in the exhaust gas,
converting them into harmless water vapor and carbon
dioxide, it also reduces NOx, converting it into nitrogen.
The catalytic converter also has the ability to store oxygen.
The Engine Control Module (ECM) has the capability to
monitor this process using a Heated
Rear Heated Oxygen Sensor (HO2S2) located in the ex-
haust stream past the TWC. The HO2S2 produces an out-
put signal which indicates the oxygen storage capacity of
the catalyst; this in turn indicates the catalyst’s ability to
convert exhaust emissions effectively. The ECM monitors
the catalyst efficiency by first allowing the catalyst to heat
up, waiting for a stabilization period while the engine is id-
ling, and then adding and removing fuel while monitoring
the reaction of the HO2S2. When the catalyst is function-
ing properly, the HO2S2 response to the extra fuel is slow
compared to the Front Heated Oxygen Sensor (HO2S1).
When the HO2S2 response is close to that of the HO2S1,
the Oxygen storage capability or efficiency of the catalyst
is considered to be bad, and the Malfunction Indicator
Lamp (MIL) will illuminate.
Conditions for Setting the DTC
S Oxygen storage capacity index time is less than 0.3
seconds.
S Before idle test, the vehicle needs to be driven for
at least:
S 15 seconds at airflow is greater than 9.2 g/sec.
for manual transaxle.
S 11 seconds at airflow is greater than 12 g/sec
for automatic transaxle.
S Oxygen Sensor Capacity test condition:
S Closed loop stoichiometry.
S Purge concentration learned.
S Engine is running more than 330 seconds.
S Airflow is between 2.5 and 7.25 g/sec.
S Throttle Position (TP) sensor is less than 1.5%.
S Intake Air Temperature (IAT) is between –7°C
(19.4°F) and 105°C (221°F).
S Barometric pressure (BARO) is greater than 72 kPa
(10.4 psi).
S Catalyst temperature is between 500°C (932°F)
and 850°C (1562°F) for automatic transaxle.
S Catalyst temperature is between 450°C (842°F)
and 850°C (1562°F) for automatic transaxle.
S Closed Loop integrator change is less than 0.03.
S Idle time is less than 1 minute.
S Vehicle speed is less than 3 km/h (1.9 mph).S Block Learn Mode is learned.
S Above condition is stabilized for 5 seconds.
Note : Test is aborted for this idle if:
S Change in engine speed is greater than 80 rpm.
S A/C status changed.
S Cooling fan status changed.
S Insufficient air/fuel shift.
S DTC(s) P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0131, P0132, P0133, P1133,
P0134, P0135, P0137, P0138, P0140, P0141,
P1167, P1171, P0171, P0172, P0201, P0202,
P0203, P0204, P0300, P0336, P0337, P0341,
P0342, P0351, P0352, P0402, P0404, P1404,
P0405, P0406, P0443, P0502, P0506, P0507, and
P0562 are not set.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
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.
Diagnostic Aids
The catalyst test may abort due to a change in the engine
load. Do not change the engine load (i.e. A/C, coolant fan,
heater motor) while a catalyst test is in progress.
An intermittent problem may be caused by a poor connec-
tion, rubbed–through wire insulation, or a wire that is bro-
ken inside the insulation.
Any circuitry, that is suspected as causing the intermittent
complaint, should be thoroughly checked for the following
conditions:
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.

1F – 568IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1601
SPI COMMUNICATIONS BETWEEN ECM AND TCM
Circuit Description
The Serial Peripheral Interface (SPI) communication is
used internally by the Engine Control Module (ECM) to
send message between the engine processor and the au-
tomatic transaxle processor. Included in each message
sent between the two processor is a checksum of the mes-
sage. Both the engine processor automatic transaxle
processor will compare this checksum value with calcu-
lated checksum. If the checksum do not match, the proc-
essor will review the new data as being corrupted and ig-
nore the value. The processor then use the previous
message. The receiving processor will then send a mes-
sage to the sending processor informing it that its last mes-
sage was corrupted.
The ECM monitor periodic TCM status message and if
message is not received fail counter incremented and
Diagnostic trouble Code (DTC) will stored.
Conditions for Setting the DTC
S Ignition switch is turned to ON.S Ignition voltage is greater than 11 volts.
S Engine is running more than 2 seconds.
S Device Control not active.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
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.
DTC P1601 SPI Communications Between ECM and TCM
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition OFF.
2. Replace the Engine Control Module (ECM).
Is the repair complete?–Go to Step 3–
31. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 4Go to Step 2
4Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 626IENGINE CONTROLS
DAEWOO V–121 BL4
EXHAUST GAS RECIRCULATION
VA LV E
The Exhaust Gas Recirculation (EGR) system is used on
engines equipped with an automatic transaxle to lower
NOx (oxides of nitrogen) emission levels caused by high
combustion temperature. The EGR valve is controlled by
the engine control module (ECM). The EGR valve feeds
small amounts of exhaust gas into the intake manifold to
decrease combustion temperature. The amount of ex-
haust gas recirculated is controlled by variations in vacu-
um and exhaust back pressure. If too much exhaust gas
enters, combustion will not take place. For this reason,
very little exhaust gas is allowed to pass through the valve,
especially at idle.
The EGR valve is usually open under the following condi-
tions:
S Warm engine operation.
S Above idle speed.
Results of Incorrect Operation
Too much EGR flow tends to weaken combustion, causing
the engine to run roughly or to stop. With too much EGR
flow at idle, cruise, or cold operation, any of the following
conditions may occur:
S The engine stops after a cold start.
S The engine stops at idle after deceleration.
S The vehicle surges during cruise.
S Rough idle.
If the EGR valve stays open all the time, the engine may
not idle. Too little or no EGR flow allows combustion tem-
peratures to get too high during acceleration and load con-
ditions. This could cause the following conditions:
S Spark knock (detonation)
S Engine overheating
S Emission test failure
INTAKE AIR TEMPERATURE
SENSOR
The Intake Air Temperature (IAT) sensor is a thermistor,
a resistor which changes value based on the temperature
of the air entering the engine. Low temperature produces
a high resistance (4,500 ohms at –40°F [–40°C]), while
high temperature causes a low resistance (70 ohms at
266°F [130°C]).
The engine control module (ECM) provides 5 volts to the
IAT sensor through a resistor in the ECM and measures
the change in voltage to determine the IAT. The voltage will
be high when the manifold air is cold and low when the air
is hot. The ECM knows the intake IAT by measuring the
voltage.
The IAT sensor is also used to control spark timing when
the manifold air is cold.
A failure in the IAT sensor circuit sets a diagnostic trouble
code P0112 or P0113.
IDLE AIR CONTROL VALVE
Notice : Do not attempt to remove the protective cap to
readjust the stop screw. Misadjustment may result in dam-
age to the Idle Air Control (IAC) valve or to the throttle
body.
The IAC valve is mounted on the throttle body where it
controls the engine idle speed under the command of the
engine control module (ECM). The ECM sends voltage
pulses to the IAC valve motor windings, causing the IAC
valve pintle to move in or out a given distance (a step or
count) for each pulse. The pintle movement controls the
airflow around the throttle valves which, in turn, control the
engine idle speed.
The desired idle speeds for all engine operating conditions
are programmed into the calibration of the ECM. These
programmed engine speeds are based on the coolant
temperature, the park/neutral position switch status, the
vehicle speed, the battery voltage, and the A/C system
pressure (if equipped).
The ECM ”learns” the proper IAC valve positions to
achieve warm, stabilized idle speeds (rpm) desired for the
various conditions (park/neutral or drive, A/C on or off, if
equipped). This information is stored in ECM ”keep alive”
memories. Information is retained after the ignition is
turned OFF. All other IAC valve positioning is calculated
based on these memory values. As a result, engine varia-
tions due to wear and variations in the minimum throttle
valve position (within limits) do not affect engine idle
speeds. This system provides correct idle control under all
conditions. This also means that disconnecting power to
the ECM can result in incorrect idle control or the necessity
to partially press the accelerator when starting until the
ECM relearns idle control.
Engine idle speed is a function of total airflow into the en-
gine based on the IAC valve pintle position, the throttle
valve opening, and the calibrated vacuum loss through ac-
cessories. The minimum throttle valve position is set at the
factory with a stop screw. This setting allows enough air-
flow by the throttle valve to cause the IAC valve pintle to
be positioned a calibrated number of steps (counts) from
the seat during ”controlled” idle operation. The minimum
throttle valve position setting on this engine should not be
considered the ”minimum idle speed,” as on other fuel in-
jected engines. The throttle stop screw is covered with a
plug at the factory following adjustment.
If the IAC valve is suspected as the cause of improper idle
speed, refer to ”Idle Air Control System Check” in this sec-
tion.
MANIFOLD ABSOLUTE PRESSURE
SENSOR
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load and speed changes. It converts these to
a voltage output.

SECTION : 3A
AUTOMATIC TRANSAXLE DRIVE AXLE
TABLE OF CONTENTS
SPECIFICATIONS3A–1 . . . . . . . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 3A–1. . . . . . . . . .
SPECIAL TOOLS3A–2 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools Table 3A–2. . . . . . . . . . . . . . . . . . . . . . . .
COMPONENT LOCATOR3A–2 . . . . . . . . . . . . . . . . . . . .
Front Drive Axle 3A–2. . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR3A–4 . . . . . . . . . . . . . . . ON–VEHICLE SERVICE 3A–4. . . . . . . . . . . . . . . . . . . . .
Drive Axle Assembly 3A–4. . . . . . . . . . . . . . . . . . . . . . .
UNIT REPAIR 3A–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outer Joint Seal 3A–7. . . . . . . . . . . . . . . . . . . . . . . . . .
Inner Tripot Seal 3A–8. . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION3A–10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Drive Axle 3A–10. . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
ApplicationNSmLb–FtLb–In
Axle Shaft Caulking Nut300221–
Lower Ball Joint Pinch Bolt and Nut6044–
Tie Rod Nut5541–
Wheel Nuts10074–

3A – 2IAUTOMATIC TRANSAXLE DRIVE AXLE
DAEWOO V–121 BL4
SPECIAL TOOLS
SPECIAL TOOLS TABLE
J–8059
Snap Ring Pliers
KM–507–B
Ball Joint Remover
DW340–110
Axle Shaft Remover
J–35566
Seal Clamp Pliers
COMPONENT LOCATOR
FRONT DRIVE AXLE

AUTOMATIC TRANSAXLE DRIVE AXLE 3A – 3
DAEWOO V–121 BL4
1. C/V Joint Assembly
2. C/V Joint
3. Seal Retaining Clamp
4. Drive Axle Outboard Seal
5. Seal Retaining Clamp
6. Axle Shaft (Left–hand Drive Shown, Right–hand
Drive Similar)7. Seal Retaining Clamp
8. Drive Axle Inboard Seal
9. Seal Retaining Clamp
10. Tripot Housing
11. Snap Ring
12. Tripot Joint Assembly

3A – 4IAUTOMATIC TRANSAXLE DRIVE AXLE
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
DRIVE AXLE ASSEMBLY
Tools Required
KM–507–B Ball Joint Separator
DW340–110 Axle Shaft Remover
Removal Procedure
1. Raise and suitably support the vehicle.
2. Remove the wheels. Refer to Section 2E, Tires
and Wheels.
3. Remove the axle shaft caulking nut. Discard the
nut.
Notice : Use only the recommended tool for separating
the lower ball joint. Failure to use the recommended tool
may cause damage to the ball joint and the seal.
4. Remove the lower ball joint pinch bolt and nut.
5. Separate the steering knuckle from the lower ball
joint using the ball joint separator KM–507–B.
6. Remove the tie rod nut.
Notice : Use only the recommended tool for separating
the tie rod from the knuckle/strut assembly. Failure to use
the recommended tool may cause damage to the knuckle/
strut assembly.
7. Separate the tie rod end using the ball joint separa-
tor KM–507–B.

AUTOMATIC TRANSAXLE DRIVE AXLE 3A – 5
DAEWOO V–121 BL4
8. Remove the damping block connection nut and
bolt.
9. Remove the rear mounting bracket bolts and the
bracket.
10. Push the drive axle shaft from the wheel hub.
Important : Support the unfastened end of the drive axle.
Do not allow the drive axle to dangle freely from the trans-
axle for any length of time after it has been removed from
the wheel hub.
Important : Place a drain pan below the transaxle to catch
the escaping fluid. Cap the transaxle drive opening after
the drive axle has been removed to keep the fluid in and
any contamination out.
11. Remove the drive axle from the transaxle using the
axle shaft remover DW340–110.
Installation Procedure
Notice : Do not damage the seals.
1. Clean the hub seal and the transaxle seal.
2. Install the drive axle into the transaxle.
3. Install the wheel hub onto the axle shaft.
4. Install the rear mounting bracket bolts and the bra-
ket.
Tighten
Tighten the rear mounting bracket bolts to 62 NSm (45
lb–ft).
5. Install the damping block connection nut and bolt.
Tighten
Tighten the damping block connection nut and bolt to
68 NSm (50 lb–ft).