Downloaded from www.Manualslib.com manuals search engine 1A-124 Engine General Information and Diagnosis:
DTC P0420: Catalyst System Efficiency below ThresholdS6RW0D1104045
System and Wiring Diagram
Circuit Description
ECM monitors oxygen concentration in the exhaust gas which has passed the warm up three way catalytic converter
by HO2S-2. When the catalyst is functioning properly, the variation cycle of HO2S-2 output voltage (oxygen
concentration) is slower than that of HO2S-1 output voltage because of the amount of oxygen in the exhaust gas
which has been stored in warm up three way catalytic converter.
DTC Detecting Condition and Trouble Area
C01-11
C01-10
C01-57
WHT
BRN
1
32
4
5 VORNORN
BLUWHTBLUWHT5
E01C01
3 4
18 19 5 6 7 10 11
17 20
47 46 49 50 51 21 22
5216 259
24 14
29
55 57 54 53 59
60 582
26 27 28 15
30
56 4832 31 34 35 36 37 40 42 39 38 44
45 43 41 331 12 13
238 3 4
18 19 5 6 7 10 11
17 20
47 46 49 50 51 21 22
5216 259
24 14
29
55 57 54 53 59
60 582
26 27 28 15
30
56 4832 31 34 35 36 37 40 42 39 38 44
45 43 41 331 12 13
238
I6RW0D110038-01
1. HO2S-1 3. Warm up three way catalytic converter 5. ECM
2. HO2S-2 4. Three way catalytic converter
DTC detecting condition Trouble area
• While vehicle running at constant speed under other than high load.
• Time from rich or lean switching command is output till HO2S-2
output voltage crosses 0.45 V is less than specified value.
(2 driving cycle detection logic, monitoring once / 1 driving)• Exhaust gas leak
• Warm up three way catalytic converter
malfunction
• HO2S-2 malfunction
• HO2S-1 malfunction
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-125
DTC Confirmation Procedure
WARNING!
• When performing a road test, select a place where there is no traffic or possibility of a traffic
accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 2 persons, a driver and a tester, on a level road.
NOTE
Check to make sure that following conditions are satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 (14 °F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine coolant temp.: 70 °C, 158 °F or more
• Altitude (barometric pressure): 2500 m, 8200 ft or less (560 mmHg, 74.4 kPa or more)
1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Increase vehicle speed to 40 – 50 mph, 60 – 80 km/h.
4) Keep above vehicle speed for 10 min. or more (Throttle valve opening is kept constant in this step).
5) Stop vehicle.
6) For european market model, check whether catalyst monitoring readiness/monitoring test has completed or not by
using scan tool.
If evaporative system readiness/monitoring test has not completed, check vehicle conditions (environmental) and
repeat Steps 3) through 5).
7) Check DTC and pending DTC.
DTC Troubleshooting
NOTE
Before this troubleshooting is performed, read the precautions for DTC troubleshooting referring to
“Precautions for DTC Troubleshooting”.
Step Action Yes No
1Was “Engine and Emission Control System Check”
performed?Go to Step 2. Go to “Engine and
Emission Control
System Check”.
2Exhaust system visual check
1) Check exhaust system for leaks, damage and loose
connection.
Is it in good condition?Go to Step 3. Repair or replace
defective part.
3HO2S-2 output voltage check
1) Check output voltage of HO2S-2 referring to “DTC
P0137 / P0138: O2 Sensor (HO2S) Circuit Low Voltage /
High Voltage (Sensor-2)”.
Is check result satisfactory?Replace exhaust
manifold (built in warm
up three way catalytic
converter) and exhaust
center pipe (built in
three way catalytic
converter).Check “BRN” and / or
“ORN” wires for open
and short, and
connections for poor
connection.
If wires and connections
are OK, replace HO2S-
2.
Downloaded from www.Manualslib.com manuals search engine 1C-8 Engine Electrical Devices:
Heated Oxygen Sensor (HO2S-1 and HO2S-2)
Heater On-Vehicle Inspection (If Equipped)
S6RW0D1306010
1) Disconnect sensor connector.
2) Using ohmmeter, measure resistance between
terminals “V
B” and “GND” of sensor connector.
If found faulty, replace oxygen sensor.
NOTE
Temperature of sensor affects resistance
value largely. Make sure that sensor heater is
at correct temperature.
Resistance of oxygen sensor heater
HO2S-1: 5.0 – 6.4 Ω at 20 °C (68 °F)
HO2S-2: 11.7 – 14.5 Ω at 20 °C (68 °F)
Viewed from terminal side
3) Connect sensor connector securely.
Heated Oxygen Sensor (HO2S-1 and HO2S-2)
Removal and Installation (If Equipped)
S6RW0D1306011
Removal
WARNING!
To avoid danger of being burned, do not
touch exhaust system when system is hot.
Oxygen sensor removal should be performed
when system is cool.
1) Disconnect negative cable at battery.
2) Disconnect connector of heated oxygen sensor and
release its wire harness from clamps.
3) Perform following items before removing heated
oxygen sensor.
a) For HO2S-1, remove exhaust manifold referring
to “Exhaust Manifold Removal and Installation in
Section 1K”, if necessary.
b) For HO2S-2, hoist vehicle.
4) Remove heated oxygen sensor from exhaust pipe or
exhaust manifold.Installation
Reverse removal procedure noting the following.
• Tighten heated oxygen sensor (1) to specified torque.
Tightening torque
Heated oxygen sensor (a): 45 N·m (4.5 kgf-m,
32.5 lb-ft)
• Install exhaust manifold referring to “Exhaust Manifold
Removal and Installation in Section 1K”, if removed.
• Connect connector of heated oxygen sensor (1) and
clamp wire harness securely.
• After installing heated oxygen sensor, start engine
and check that no exhaust gas leakage exists.
[A]: HO2S-1 [B]: HO2S-2
I4RS0A130006-01
[A]: HO2S-1 [B]: HO2S-2
[A]
[B]
1, (a)
1, (a)
I3RM0A130007-01
Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-3
Camshaft Position Control (VVT Variable Valve Timing) System DescriptionS6RW0D1401002
System Description
The VVT system is an electronic control system which continuously vary and optimize the intake valve timing in
response to the engine operating condition.
The optimized intake valve timing produce such an air intake with high efficiency that both the higher power generation
and lower fuel consumption can be attained in the whole engine speed range from low to high. In the area of the
average engine load, low emission of nitrogen oxides (NOx) and high fuel efficiency can also be attained by making
the valve opening overlap between the intake and exhaust valves longer.
For the brief of the system operation, the intake valve timing is varied by the cam timing sprocket (1) which varies the
rotational phase between the intake camshaft (3) and sprocket. The rotor (2) in the cam timing sprocket is actuated by
switching or adjusting the hydraulic pressure applied to the chambers for the timing advancing (7) and/or retarding (6).
To switch or adjust the hydraulic pressure appropriately, ECM operates the oil control valve (12) with detecting the
engine speed, intake air value, throttle opening, engine coolant temperature and camshaft position (angle).
1
4
5
10
8
9
2
7
6
12
11
3
60˚ (variable angle)
Most retarded timing Most advanced timing
Exhaust valveIntake valve
Crank angle
Overlap of valves
Valve lift
I5RW0C140002-01
4. Oil passage to chamber for timing retarding 8. Oil filter 10. Oil pan
5. Oil passage to chamber for timing advancing 9. Oil pump 11. Control signal from ECM
Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-5
Targeted Timing Varying Operation
Diagnostic Information and Procedures
Compression CheckS6RW0D1404001
Check compression pressure on all 4 cylinders as
follows:
1) Warm up engine to normal operating temperature.
2) Stop engine after warming up.
NOTE
After warming up engine, place transmission
gear shift lever in “Neutral” (shift selector
lever to “P” range for A/T model), and set
parking brake and block drive wheels.
3) Remove air cleaner assembly with air suction hose
referring to “Air Cleaner Assembly Removal and
Installation”.
4) Remove cylinder head upper cover.
5) Remove ignition coil assemblies and all spark plugs
referring to “Spark Plug Removal and Installation in
Section 1H”.
6) Disconnect fuel injector wires at the coupler.7) Install special tools (Compression gauge) into spark
plug hole.
Special tool
(A): 09915–64512
(B): 09915–64530
(C): 09915–67010 Driving condition Valve timing Target of control Effect
Engine running at idle
speedMost retardedTo shorten the valve opening overlap in
order to prevent the exhaust gas
counterflow to intake manifold.Stabilization of the engine
rotation at idle speed.
Average engine load
rangeTo the advanced
sideTo lengthen the valve opening overlap
in order to enhance the internal
exhaust gas recirculation and reduce
the pumping loss.Improvement of the fuel
efficiency.
Lowering of the exhaust
emission.
Light engine load
rangeTo the retarded sideTo shorten the valve opening overlap in
order to prevent the exhaust gas
counterflow to intake manifold.Keeping of the engine stability.
Low or average
engine speed range
with heavy engine
loadTo the advanced
sideTo advance the closing timing of the
intake valve in order to improve the
volumetric efficiency.Improvement of generating the
engine torque at low and
average engine speed.
High engine speed
range with heavy
engine loadTo the retarded sideTo retard the closing timing of the
intake valve in order to improve the
volumetric efficiency.Improvement of generating the
engine power.
Low engine coolant
temperatureMost retardedTo shorten the valve opening overlap in
order to prevent the exhaust gas
counterflow to intake manifold and
reduce the fuel increasing.
To slow the fast idle speed of the
engine as a result of stabilizing the
engine idling.Stabilization of the fast idling of
the engine.
Improvement of the fuel
efficiency.
At engine starting and
stoppingMost retardedTo shorten the valve opening overlap in
order to prevent the exhaust gas
counterflow to intake manifold.Improvement of start ability.
(A)
(C)
(B)
I3RH0B140009-01
Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-7
7) Install air cleaner assembly with air suction hose
referring to “Air Cleaner Assembly Removal and
Installation”.
8) Run engine at specified idle speed and read vacuum
gauge. Vacuum should be within specification.
Vacuum specification (at sea level)
59 – 73 kPa (45 – 55 cmHg, 17.7 – 21.6 in.Hg) at
specified idle speed
9) After checking, disconnect special tool (Vacuum
gauge) from PCV valve.
10) Detach blind cap from PCV valve.
11) Install air cleaner assembly with air suction hose
referring to “Air Cleaner Assembly Removal and
Installation”.
Valve Lash (Clearance) InspectionS6RW0D1404003
1) Remove negative cable at battery.
2) Remove cylinder head cover referring to “Cylinder
Head Cover Removal and Installation”.
3) Remove right side engine under cover, if necessary.
4) Using 17 mm wrench, turn crankshaft pulley (1)
clockwise until cam lobes (2) become perpendicular
to shim faces (3) at valves “1” and “7” as shown in
figure.
5) Check valve lashes with thickness gauge (4)
according to the following procedure.
a) Check valve lashes at valves “1” and “7”.
b) Turn camshafts by 90° (by turning crankshaft
with wrench).
c) Make sure that cam lobes are perpendicular to
shim faces at valves to be checked (in this case,
“3” and “8”), if not, adjust it by turning crankshaft.
Check valve lashes.
d) In the same manner as b) – c), check valve
lashes at valves “4” and “6”.
e) In the same manner as b) – c) again, check
valve lashes at valves “2” and “5”.
If valve lash is out of specification, record valve lash and
adjust it to specification by replacing shim.
Valve clearance specification
When cold (Coolant temperature is 15 – 25 °C (59 –
77 °F)):
• Intake: 0.18 – 0.22 mm (0.007 – 0.009 in.)
• Exhaust: 0.28 – 0.32 mm (0.011 – 0.013 in.)
When hot (Coolant temperature is 60 – 68 °C (140 –
154 °F)):
• Intake: 0.21 – 0.27 mm (0.008 – 0.011 in.)
• Exhaust: 0.30 – 0.36 mm (0.012 – 0.014 in.)Replacement of Shim
1) Close the valve whose shim (2) is to be replaced by
turning crankshaft, then turn tappet (3) till its cut
section (1) faces inside as shown in figure.
I3RM0A140004-01
I2RH0B140006-01
Downloaded from www.Manualslib.com manuals search engine 1D-8 Engine Mechanical:
2) Lift down the valve by turning crankshaft to 360°.
3) Hold tappet at that position using special tool as
follows.
a) Remove its housing bolts.
b) Check housing No. and select special tool
corresponding to housing No., referring to
“Special tool selection table”.
Special tool selection table
c) Hold down the tappet so as not to contact the
shim by installing special tool on camshaft
housing with housing bolt (1) tighten housing
bolts by hand.
Special tool
(A): 09916–67020
(A): 09916–670214) Turn camshaft by approximately 90° clockwise and
remove shim (3).
WARNING!
Never put in the hand between camshaft and
tappet.
5) Using a micrometer (2), measure the thickness of
the removed shim (1), and determine replacement
shim by calculating the thickness of new shim with
the following formula and table.
Shim thickness specification
Intake side:
A = B + C – 0.20 mm (0.008 in.)
Exhaust side:
A = B + C – 0.30 mm (0.012 in.)
A: Thickness of new shim
B: Thickness of removed shim
C: Measured valve clearance
For example of intake side:
When thickness of removed shim is 2.40 mm (0.094
in.), and measured valve clearance is 0.45 mm
(0.018 in.).
A = 2.40 mm (0.094 in.) + 0.45 mm (0.018 in.) – 0.20
mm (0.008 in.) = 2.65 mm (0.104 in.)
Calculated thickness of new shim = 2.65 mm (0.104
in.) No. on camshaft
housingEmbossed mark on special
tool
I2 IN2
I3, I4, I5 IN345
E2 EX2
E3, E4, E5 EX345A: I: Intake side or E: Exhaust side
B: Position from timing chain side
C: Pointing to timing chain side
I2RH0B140011-01
I5RW0C140003-01
1. Special tool 2. Magnet
I2RH0B140013-01
I2RH0B140014-01
Downloaded from www.Manualslib.com manuals search engine 1D-18 Engine Mechanical:
17) Remove oil pressure switch bracket (1).
18) Remove suspension control arm referring to
“Suspension Control Arm / Bushing Removal and
Installation in Section 2B”.
19) Disconnect right and left drive shaft joints from
differential gear referring to “Front Drive Shaft
Assembly Removal and Installation in Section 3A”.
20) Remove exhaust No.1, No.2 and center pipes
referring to “Exhaust System Components in Section
1K”.
21) Disconnect propeller shaft referring to “Propeller
Shaft Assembly Removal and Installation in Section
3D” (for 4WD model).
22) Disconnect steering lower shaft from pinion shaft
referring to “Steering Lower Shaft Removal and
Installation in Section 6B”.
23) Fix radiator to body with rope in order to avoid the
radiator fall off when front lower cross member
lowered.
24) Support front suspension frame, front lower cross
member and oil pan using jack at hatched parts (1)
indicated in figure.
[A]: View A [C]: For A/T model
6
3 45
1 7 7
2
8
9
10
A
15
14
16
20 19
26
24
27
12
13 [A]
11
34
232122
25
17 2818 [B] [C]
2930
31
32
17
33
I5RW0C140010-01
[B]: For M/T model 34. steering gear box
2. Exhaust manifold
1
2
I5RW0A140011-01
11
I5RW0A140012-01