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 – 606IENGINE CONTROLS
DAEWOO V–121 BL4
7. Connect the TP sensor connector and the IAC
valve connector.
8. Connect the coolant hoses to the throttle body.
9. Connect the vacuum hoses to the throttle body.
Important : Make sure the throttle/cruise control cables
do not hold the throttle open. With the engine off, check to
see that the accelerator pedal is free.
10. Connect the throttle cable.
11. Install the air intake tube.
12. Connect the breather hose to the valve cover.
13. Connect the IAT sensor connector.
14. Connect the negative battery cable.
15. Fill the cooling system.
FRONT HEATED OXYGEN SENSOR
(HO2S1) (1.4L/1.6L DOHC)
Removal Procedure
1. Disconnect the negative battery cable.
Notice : The oxygen sensor uses a permanently attached
pigtail and connector. This pigtail should not be removed
from the oxygen sensor. Damage or removal of the pigtail
or the connector could affect proper operation of the oxy-
gen sensor. Take care when handling the oxygen sensor.
Do not drop the oxygen sensor.
2. Disconnect the front heated oxygen sensor
(HO2S1) connector.
Notice : The oxygen sensor may be difficult to remove
when engine temperature is below 48°C (120°F). Exces-
sive force may damage threads in the exhaust manifold.
3. Carefully remove the HO2S1 from the exhaust
manifold.
Installation Procedure
Important : A special anti–seize compound is used on the
oxygen sensor threads. This compound consists of a liq-
uid graphite and glass beads. The graphite will burn away,
but the glass beads will remain, making the sensor easier
to remove. New or service sensors will already have the
compound applied to the threads. If a sensor is removed
from any engine and if for any reason it is to be reinstalled,
the threads must have anti–seize compound applied be-
fore reinstallation.
1. Coat the threads of the HO2S1 with an anti–seize
compound, if needed.
2. Install the HO2S1 into the exhaust manifold.
Tighten
Tighten the oxygen sensor to 42 NSm (31 lb–ft).
3. Connect the HO2S1 connector.
4. Connect the negative battery cable.
1F – 630IENGINE CONTROLS
DAEWOO V–121 BL4
COMPREHENSIVE COMPONENT
MONITOR DIAGNOSTIC OPERATION
Comprehensive component monitoring diagnostics are
required to monitor emissions–related input and output
powertrain components.
Input Components
Input components are monitored for circuit continuity and
out–of–range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable, i.e.
Throttle Position (TP) sensor that indicates high throttle
position at low engine loads or Manifold Absolute Pressure
(MAP) voltage. Input components may include, but are not
limited to, the following sensors:
S Vehicle Speed Sensor (VSS).
S Crankshaft Position (CKP) sensor.
S Throttle Position (TP) sensor.
S Engine Coolant Temperature (ECT) sensor.
S Camshaft Position (CMP) sensor.
S Manifold Absolute Pressure (MAP) sensor.
In addition to the circuit continuity and rationality check,
the ECT sensor is monitored for its ability to achieve a
steady state temperature to enable closed loop fuel con-
trol.
Output Components
Output components are diagnosed for proper response to
control module commands. Components where functional
monitoring is not feasible will be monitored for circuit conti-
nuity and out–of–range values if applicable. Output com-
ponents to be monitored include, but are not limited to the
following circuit:
S Idle Air Control (IAC) Motor.
S Control module controlled EVAP Canister Purge
Valve.
S A/C relays.
S Cooling fan relay.
S VSS output.
S MIL control.
Refer to ”Engine Control Module” and Sensors in this sec-
tion.
Passive and Active Diagnostic Tests
A passive test is a diagnostic test which simply monitors
a vehicle system or component. Conversely, an active
test, actually takes some sort of action when performing
diagnostic functions, often in response to a failed passive
test. For example, the Exhaust Gas Recirculation (EGR)
diagnostic active test will force the EGR valve open during
closed throttle deceleration and/or force the EGR valve
closed during a steady state. Either action should result in
a change in manifold pressure.
Intrusive Diagnostic Tests
This is any on–board test run by the Diagnostic Manage-
ment System which may have an effect on vehicle perfor-
mance or emission levels.
Warm–Up Cycle
A warm–up cycle means that engine temperature must
reach aminimum of 160°F (70°C) and rise at least 72°F
(22°C) over the course of a trip.
Freeze Frame
Freeze Frame is an element of the Diagnostic Manage-
ment System which stores various vehicle information at
the moment an emissions–related fault is stored in
memory and when the Malfunction Indicator Lamp (MIL)
is commanded on. These data can help to identify the
cause of a fault.
Failure Records
Failure Records data is an enhancement of the EOBD
Freeze Frame feature. Failure Records store the same ve-
hicle information as does Freeze Frame, but it will store
that information for any fault which is stored in onboard
memory, while Freeze Frame stores information only for
emission–related faults that command the MIL on.
COMMON EOBD TERMS
Diagnostic
When used as a noun, the word diagnostic refers to any
on–board test run by the vehicle’s Diagnostic Manage-
ment System. A diagnostic is simply a test run on a system
or component to determine if the system or component is
operating according to specification. There are many diag-
nostics, shown in the following list:
S Misfire
S Front Heated Oxygen Sensor (HO2S1)
S Rear Heated Oxygen Sensor (HO2S2)
S Exhaust Gas Recirculation (EGR)
S Catalyst monitoring
Enable Criteria
The term ”enable criteria” is engineering language for the
conditions necessary for a given diagnostic test to run.
Each diagnostic has a specific list of conditions which
must be met before the diagnostic will run.
”Enable criteria” is another way of saying ”conditions re-
quired.”
The enable criteria for each diagnostic is listed on the first
page of the Diagnostic Trouble Code (DTC) description
under the heading ”Conditions for Setting the DTC.” En-
able criteria varies with each diagnostic and typically in-
cludes, but is not limited to, the following items:
S Engine speed.
S Vehicle speed
S Engine Coolant Temperature (ECT)
S Manifold Absolute Pressure (MAP)
TIRES AND WHEELS 2E – 11
DAEWOO V–121 BL4
pacity, diameter, rim width, offset, and mounting configu-
ration. A wheel of improper size or type may affect wheel
and bearing life, brake cooling, speedometer/odometer
calibration, vehicle ground clearance, and tire clearance
to the body and the chassis. The wheel offset is 49 ± 1 mm
(1.93 ± 0.04 inches). Steel wheels may be identified by a
two– or three–letter code stamped into the rim near the
valve stem. Alloy wheels should have the code, the part
number, and the manufacturer ID cast into the back side.
INFLATION O TIRES
The pressure recommended for any vehicle line is careful-
ly calculated to give a satisfactory ride, handling, tread life,
and load–carrying capacity.
Tire pressure should be checked monthly or before any
extended trip. Check the tires when they are cold, after the
vehicle has sat for 3 hours or more, or has been driven less
than 1 mile. Set the tire pressure to the specifications on
the tire label located on the rear face of the driver’s door.
Tire inflation pressure is also given under ”Tire Size and
Pressure Specifications” in this section.
Valve caps or extensions should be on the valves to keep
dust and water out.
For sustained driving at speeds up to 140 km/h (85 mph),
inflate the tires to the pressure recommended on the tire.
Sustained driving at speeds faster than 140 km/h (85mph), even if permitted by law, is not advised unless the
vehicle has special high–speed tires available from many
tire dealers. Tire pressures may increase as much as 41
kPa (6 psi) when the tires are hot.
Higher than recommended tire pressure can cause
S Hard ride.
S Tire bruising or damage.
S Rapid tread wear at the center of the tire.
Lower than recommended pressure can cause
S Tire squeal on turns.
S Hard steering.
S Rapid and uneven wear on the edges of the tread.
S Tire rim bruises and rupture.
S Tire cord breakage.
S High tire temperatures.
Unequal tire pressures on same axle can cause
S Uneven braking.
S Steering lead.
S Reduced handling.
S Swerve on acceleration.
S Torque steer.
4–2WUSAGE AND CAPACITY OF FUSES IN FUSE BLOCK
1. ENGINE ROOM RELAY AND FUSE BLOCK
1) POSITION OF RELAY AND FUSE
2) USAGE OF FUSE IN ENGINE FUSE BLOCK
Power
Supply
ClassificationFuse
NoCapacityUsage
Ef130ABattery Main(F13~F16, F21~F24)
Ef260AEBCM, Oil Feeding Conenctor
Ef330ABlower Relay
30SBEf430AIgnition Switch–2
BAT (+)(Slow–BlownEf530AIgnition Switch–1
Fuse)Ef620ACooling Fan Low Relay
Ef730ADefog Relay
Ef830ACooling Fan HI Relay
IGN2 (15A)Ef920APower Window Switch
IGN1 (15)Ef1015AFuel Connector, ECM (MR–140), LEGR, EI
System
30Ef1110AECM, Main Relay (Sirius D4)
BAT(+)Ef1225AHead lamp Relay, ILLUM. Relay
Ef1315ABrake Switch
IGN2 (15A)Ef1420APower Window Switch
56 LIGHTEf1515AHead Lamp HI
30Ef1615AHorn Relay, siren, Hood Contact Switch
BAT(+)Ef1710AA/C Comp. Relay
IGN1 (15)Ef1815AFuel Pump
30 BAT(+)Ef1915ACluster, Key Remind S/W, Folding Mirror Unit, MAP
Lamp, Room Lamp, Trunk Open lamp, Trunk
Open S/W
56 LIGHTBlade TypeEf2010AHead Lamp Low
IGN1 (15)/FuseEf2115AEVAP Canister Purge Solenoid, HO2S, Cooling
Fan Relay
30 BAT(+)Ef2215Ainjector, EGR, EEGR
ILLUM. (58)Ef2310ALicense Plate Lamp, Chime Bell, Tail Lamp, Head
Lamp
30 BAT (+)Ef2415AFog Lamp Relay
IGN2 (15A)Ef2510AElectric OSRV Mirror
30 BAT (+)Ef2615ACentral Door Lock Unit
56 LIGHTEf2710AHead Lamp Low
ILLUM. (58)Ef2810AILLUM. Circuit, Head Lamp, Tail Lamp
SPAREEf2910ANot Used
Ef3015ANot Used
Ef3125ANot Used
4–4WUSAGE AND CAPACITY OF FUSES IN FUSE BLOCK
3. POSITION OF CONTROL UNIT, RELAY AND PART NUMBER
1) ENGINE FUSE BLOCK
Part Name
Part No.Remarks
Front Fog Relay96190187
ILLUM. Relay96190187
Cooling Fan Low Relay96190189
Cooling Fan HI Relay96190189
A/C Comp. Relay96190187
Horn Relay96190187
Defog Relay96190189
Fuel Relay96190189
Main/Ignition Relay96190189
Power Window Relay96190189
Head Lamp Relay96190189
2) BEHIND DRIVER LEG ROOM CONNECTOR HOLDER
Part Name
Part No.Remarks
Rear Fog Relay96344573
PNP Relay96190189
Blink Unit96312545
Blower Relay96190189
3) DRIVER LEG ROOM
Part Name
Part No.Remarks
Chime Bell96459510
TCM (MR–140/HV–240)96342619
TCM (SIRIUS D4)96497032
4) BEHIND LEFT HEAD LAMP
Part Name
Part No.Remarks
Cooling Fan Control Relay96251271
5) UNDER LEFT PASSENGER LEG ROOM
Part Name
Part No.Remarks
Central Door Lock Unit96552824
6) FLOOR PANEL BELOW CONSOLE
Part Name
Part No.Remarks
Anti Theft Control Unit96407681Wes t Euro
96404668General
SDM96406712
7) BESIDE ENGINE FUSE BLOCK
Part Name
Part No.Remarks
EBCM96549742
5–4WELECTRICAL WIRING DIAGRAMS
8. FATC (FULL AUTOMATIC TEMPERATURE CONTROL) 5–68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) BLOWER MOTOR, INTAKE MOTOR, MODE MOTOR, MAX HIGH RELAY & POWER TR CIRCUIT 5–68. . . .
2) SENSOR(AMBIENT,INCAR,SUN&WATER), AIR MIX DOOR MOTOR, A/C COMPRESSOR & ECM
CIRCUIT5–70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–1) MR–140/HV–2405–70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2) SIRIUS D45–72 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9. RADIATOR COOLING FAN CIRCUIT 5–74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) COOLING FAN CIRCUIT(MR–140/HV–240) : DUAL 5–74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2) COOLING FAN CIRCUIT(MR–140/HV–240) : SINGLE 5–76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3) COOLING FAN CIRCUIT(SIRIUS D4) : DUAL 5–78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4) COOLING FAN CIRCUIT(SIRIUS D4) : SINGLE 5–80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10. HEAD LAMP & HEAD LAMP LEVELING DEVICE(HLLD) CIRCUIT 5–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) NOTCH BACK5–82 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2) HATCH BACK5–84 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11. ILLUMINATION CIRCUIT5–86 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) ILLUMINATION CIRCUIT– W/O DIMMER CONTROL 5–86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2) ILLUMINATION CIRCUIT– W/ DIMMER CONTROL 5–88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3) LAMP(LICENSE PLATE & W/ FRONT/REAR POSITION) CIRCUIT : NOTCH BACK 5–90. . . . . . . . . . . . . . . . . .
4) LAMP(LICENSE PLATE & W/ FRONT/REAR POSITION) CIRCUIT : HATCH BACK 5–92. . . . . . . . . . . . . . . . . .
12. FRONT & REAR FOG LAMP CIRCUIT 5–94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) NOTCH BACK5–94 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2) HATCH BACK5–96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13. HAZARD & TURN SIGNAL LAMP CIRCUIT 5–98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) NOTCH BACK5–98 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2) HATCH BACK5–100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–74WELECTRICAL WIRING DIAGRAMS
9. RADIATOR COOLING FAN CIRCUIT
1) COOLING FAN CIRCUIT (MR–140/HV–240) : DUAL
a. CONNECTOR INFORMATION
CONNECTOR(NO.)
(PIN NO. COLOR)
CONNECTING, WIRING HARNESSCONNECTOR POSITION
C101 (21 Pin, White)Body Engine Fuse BlockEngine Fuse Block
C102 (11 Pin, White)Body Engine Fuse BlockEngine Fuse Block
C104 (24 Pin, White)Front Engine Fuse BlockEngine Fuse Block
C106 (20 Pin, White)Engine Engine Fuse BlockEngine Fuse Block
C108 (24 Pin, Black)Body EngineLeft Engine Fuse Block
C113 (16 Pin, Black)Body FrontBehind ECM Bracket
C201 (76 Pin, Black)I.P I.P Fuse BlockI.P Fuse Block
C202 (89 Pin, White)I.P BodyLeft CO–Driver Leg Room
G101FrontBehind Left Head Lamp
G102FrontBehind Right Head Lamp
G107Engine (MR–140/HV–240)Under Start Motor
b. CONNECTOR IDENTIFICATION SYMBOL & PIN NUMBER POSITION