DTC P2A00, P2A03 A/F SENSOR 1EC-575
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Revision: November 2009 2006 QX56
DTC P2A00, P2A03 A/F SENSOR 1PFP:22693
Component DescriptionUBS00N7D
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800 °C (1,292 - 1,472 °F).
CONSULT-II Reference Value in Data Monitor ModeUBS00N7E
Specification data are reference values.
On Board Diagnosis LogicUBS00N7F
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to LEAN side or RICH side.
DTC Confirmation ProcedureUBS00N7G
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT ” in “WORK SUPPORT” mode with CON-
SULT-II.
SEF579Z
SEF580Z
MONITOR ITEM CONDITIONSPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
Engine: After warming up Maintaining engine speed at 2,000 rpm Fluctuates around 1.5 V
DTC No. Trouble diagnosis name DTC detecting conditionPossible Cause
P2A00
2A00
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit range/performance
The output voltage computed by ECM from the
A/F sensor 1 signal is shifted to the lean side
for a specified period.
The A/F signal computed by ECM from the A/F
sensor 1 signal is shifted to the rich side for a
specified period.
A/F sensor 1
A/F sensor 1 heater
Fuel pressure
Fuel injector
Intake air leaks
P2A03
2A03
(Bank 2)
EM-4Revision: November 2009
PRECAUTIONS
2006 QX56
Before starting engine, apply fuel pressure to fuel lines with turning ignition switch ON (with engine
stopped). Then make sure that there are no leaks at fuel line connections.
After repairing, start engine and increase engine speed to check engine coolant, fuel, oil, and exhaust
systems for leakage.
Parts Requiring Angular TighteningEBS00REO
For final tightening of the following engine parts use Tool:
–Cylinder head bolts
–Main bearing cap bolts
–Connecting rod cap bolts
–Crankshaft pulley bolt (No angle wrench is required as the bolt flange is provided with notches for angle
tightening)
Do not use a torque value for final tightening.
The torque value for these parts are for a preliminary step.
Ensure thread and seat surfaces are clean and lightly coated with engine oil.
Precautions for Liquid GasketEBS00REP
REMOVAL OF LIQUID GASKET SEALING
After removing the bolts and nuts, separate the mating surface
and remove the old liquid gasket sealing using Tool.
CAUTION:
Do not damage the mating surfaces.
Tap the seal cutter to insert it.
In areas where the Tool is difficult to use, lightly tap to slide it.
LIQUID GASKET APPLICATION PROCEDURE
1. Remove the old liquid gasket adhering to the gasket applicationsurface and the mating surface using suitable tool.
Remove the liquid gasket completely from the groove of the
liquid gasket application surface, bolts, and bolt holes.
2. Thoroughly clean the mating surfaces and remove adhering moisture, grease and foreign material.
3. Attach the liquid gasket tube to the Tool. Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-46, "
Recommended Chemical Products and Sealants" .
4. Apply the liquid gasket without breaks to the specified location with the specified dimensions.Tool number : KV10112100 (BT-8653-A)
Tool number : KV10111100 (J-37228)
WBIA0566E
PBIC0003E
Tool number : WS39930000 ( — )
WBIA0567E
EM-6Revision: November 2009
PREPARATION
2006 QX56
PREPARATIONPFP:00002
Special Service ToolsEBS00REQ
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.Tool number
(Kent-Moore No.)
Tool name Description
KV10111100
(J-37228)
Seal cutter Removing steel oil pan and rear timing chain
case
—
(J-44626)
Air fuel sensor Socket Loosening or tightening air fuel ratio A/F sen-
sor
a: 22 mm (0.87 in)
EG15050500
(J-45402)
Compression gauge adapter Inspecting compression pressure
KV10116200
(J-26336-A)
Valve spring compressor
1. KV10115900
(J-26336-20)
Attachment
2. KV10109220
( — )
Adapter Disassembling valve mechanism
Part (1) is a component of KV10116200 (J-
26336-A), but part (2) is not.
KV10112100
(BT-8653-A)
Angle wrench Tightening bolts for cylinder head, main bear-
ing cap and connecting rod cap
KV10107902
(J-38959)
Valve oil seal puller Removing valve oil seal
S-NT046
LBIA0444E
ZZA1225D
PBIC1650E
S-NT014
S-NT011
EM-18Revision: November 2009
INTAKE MANIFOLD
2006 QX56
Perform the following steps to disconnect the quick connector
using Tool.
a. Remove quick connector cap (engine side only).
b. With the sleeve side of Tool facing quick connector, install Tool onto fuel tube.
c. Insert Tool into quick connector until sleeve contacts and goes no further. Hold the Tool in that position.
CAUTION:
Inserting the Tool hard will not disconnect quick connector.
Hold Tool where it contacts and goes no further.
d. Draw and pull out quick connector straight from fuel tube. CAUTION:
Pull quick connector holding "A" position in illustration.
Do not pull with lateral force applied. O-ring inside quick
connector may be damaged.
Prepare container and cloth beforehand as fuel will leak out.
Avoid fire and sparks.
Be sure to cover openings of disconnected pipes with plug or plastic bag to avoid fuel leakage
and entry of foreign materials.
6. Remove or disconnect harnesses, brackets, vacuum hose, vacuum gallery and PCV hose and tube from intake manifold.
7. Remove electric throttle control actuator by loosening bolts diagonally.
CAUTION:
Handle carefully to avoid any damage to the electric throttle control actuator.
Do not disassemble.
8. Remove the fuel injectors and fuel tube assembly. Refer to EM-31, "
REMOVAL" .
9. Loosen the bolts in reverse order shown using power tool.
10. Remove the intake manifold. CAUTION:
Cover engine openings to avoid entry of foreign materials.
Clean all gasket mating surfaces, do not reuse gaskets.Tool number : 16441 6N210 (J-45488)
SBIA0354E
WBIA0604E
KBIA2462E
INTAKE MANIFOLDEM-19
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Revision: November 2009 2006 QX56
INSTALLATION
Installation is in the reverse order of removal.
Tighten the intake manifold bolts in numerical order as shown.
Install the EVAP canister purge control solenoid valve connector with it facing front of engine.
Tighten the electronic throttle control actuator bolts of the electric throttle control actuator equally and
diagonally in several steps.
After installation perform procedure in EM-20, "INSPECTION AFTER INSTALLATION" .
Install the water hose so that its overlap width for connection is between 27 mm (1.06 in) and 32 mm (1.26
in) (target: 27 mm 1.06 in).
Connecting Quick Connector of Fuel Tube
Install quick connector as follows (the steps are the same for quick connectors on both engine side and vehi-
cle side except for the quick connector cap).
1. Make sure no foreign substances are deposited in and around tube and quick connector, and they are not
damaged.
2. Thinly apply new engine oil around the fuel tube from tip end to the spool end.
3. Align center to insert quick connector straight into fuel tube.
Insert until the paint mark for engagement identification
(white) goes completely inside quick connector so that you
cannot see it from the straight side of the connected part. Use
a mirror to check this where it is not possible to view directly
from the straight side, such as quick connector on vehicle
side.
Insert fuel tube into quick connector until top spool is com-
pletely inside quick connector, and 2nd level spool exposes
right below quick connector on engine side.
CAUTION:
Hold "A" position in illustration when inserting fuel
tube into quick connector.
Carefully align center to avoid inclined insertion to pre-
vent damage to O-ring inside quick connector.
Insert until you hear a "click" sound and actually feel
the engagement.
To avoid misidentification of engagement with a similar
sound, be sure to perform the next step.
4. Pull quick connector by hand holding "A" position. Make sure it is completely engaged (connected) so that it does not come out from fuel tube.
NOTE:
Recommended pulling force is 50 N (5.1 kg, 11.2 lb).
KBIA2462E
PBIC0017E
KBIA0272E
EM-20Revision: November 2009
INTAKE MANIFOLD
2006 QX56
5. Install the quick connector cap on the quick connector joint (onengine side only).
6. Install the fuel hose and tube to hose clamps.
7. Refill the engine coolant. Refer to CO-11, "
REFILLING ENGINE
COOLANT" .
INSPECTION AFTER INSTALLATION
After installing fuel tubes, make sure there is no fuel leakage at connections in the following steps.
–Apply fuel pressure to fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel
leaks at connections.
–Start the engine and rev it up and check for fuel leaks at the connections.
Perform procedures for “Throttle Valve Closed Position Learning ” after finishing repairs. Refer to EC-78,
"Throttle Valve Closed Position Learning" .
If electric throttle control actuator is replaced, perform procedures for “Idle Air Volume Learning” after fin-
ishing repairs. Refer to EC-78, "
Idle Air Volume Learning" .
SBIA0354E
FUEL INJECTOR AND FUEL TUBEEM-31
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Revision: November 2009 2006 QX56
FUEL INJECTOR AND FUEL TUBEPFP:16600
Removal and InstallationEBS00RF5
CAUTION:
Do not remove or disassemble parts unless instructed as shown.
REMOVAL
1. Remove the engine room cover using power tool. Refer to EM-12, "REMOVAL" .
2. Release the fuel pressure. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
3. Disconnect the negative battery terminal.
4. Disconnect the fuel injector harness connectors.
5. Disconnect the fuel hose assembly from the fuel tubes (RH and LH).
CAUTION:
While hoses are disconnected, plug them to prevent fuel from draining.
Do not separate the fuel connector and fuel hose.
6. Remove the fuel injectors with the fuel tube assembly.
1. Fuel tube (RH) 2. Cap3. Fuel damper
4. O-ring 5. O-ring (blue)6. Fuel injector
7. Clip 8. O-ring (brown)9. O-ring
10. Fuel hose assembly 11. Fuel tube (LH)
KBIA2472E
EM-32Revision: November 2009
FUEL INJECTOR AND FUEL TUBE
2006 QX56
7. Remove the fuel injector from the fuel tube using the followingsteps.
a. Spread open and remove the clip.
b. Remove the fuel injector from the fuel tube by pulling straight out.
CAUTION:
Be careful with remaining fuel that may leak out from fuel
tube.
Do not damage injector nozzles during removal.
Do not bump or drop fuel injectors.
Do not disassemble fuel injectors.
8. Remove the fuel damper from each fuel tube.
INSTALLATION
1. Install the fuel damper to each fuel tube using the following steps.
a. Apply engine oil to the new O-ring and set it into the cup of the fuel tube.
CAUTION:
Handle O-ring with bare hands. Never wear gloves.
Lubricate new O-ring with new engine oil.
Do not clean O-ring with solvent.
Make sure that O-ring and its mating part are free of for-
eign material.
When installing O-ring, do not scratch it with tool or fin-
gernails.
Do not twist or stretch the O-ring.
b. Make sure that the backup spacer is in the O-ring connecting surface of the fuel damper. NOTE:
The backup spacer is part of the fuel damper assembly.
c. Insert the fuel damper until it seats on the fuel tube. CAUTION:
Insert straight, making sure that the axis is lined up.
Do not pressure-fit with excessive force.
d. Install the cap, and then tighten the bolts evenly.
After tightening the bolts, make sure that there is no gap between the cap and fuel tube.
2. Install new O-rings to the fuel injector paying attention to the items below. CAUTION:
Upper and lower O-rings are different colors.
KBIA2506E
Reference value :130 N (13.3 kg, 29.2 lb)
Fuel tube side : Blue
Nozzle side : Brown
KBIA2473E