fuel INFINITI QX56 2006 Factory Service Manual

DTC P2A00, P2A03 A/F SENSOR 1EC-575
C
DE
F
G H
I
J
K L
M A
EC
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)

EC-582Revision: November 2009
DTC P2A00, P2A03 A/F SENSOR 1
2006 QX56
4. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT ” in “WORK SUPPORT ” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con- nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-61, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-288, "DTC
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION" or EC-299, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 5.
SEF968Y
BBIA0368E

DTC P2A00, P2A03 A/F SENSOR 1EC-585
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
11 . REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:

Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.

Before installing new A/F sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
>>INSPECTION END
Removal and InstallationUBS00N7J
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-21, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .

EC-598Revision: November 2009
FUEL INJECTOR
2006 QX56
FUEL INJECTORPFP:16600
Component DescriptionUBS00L1F
The fuel injector is a small, precise solenoid valve. When the ECM
supplies a ground to the fuel injector circuit, the coil in the fuel injec-
tor is energized. The energized coil pulls the ball valve back and
allows fuel to flow through the fuel injector into the intake manifold.
The amount of fuel injected depends upon the injection pulse dura-
tion. Pulse duration is the length of time the fuel injector remains
open. The ECM controls the injection pulse duration based on
engine fuel needs.
CONSULT-II Reference Value in Data Monitor ModeUBS00L1G
Specification data are reference values.
SEF375Z
MONITOR ITEMCONDITION SPECIFICATION
B/FUEL SCHDL See EC-134, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
INJ PULSE-B1
INJ PULSE-B2

Engine: After warming up

Air conditioner switch: OFF

Selector lever: P or N

No load Idle
2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec

FUEL INJECTOREC-599
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
Wiring DiagramUBS00L1H
BBWA2124E

EC-600Revision: November 2009
FUEL INJECTOR
2006 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureUBS00L1I
1. INSPECTION START
Turn ignition switch to START.
Is any cylinder ignited?
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
21
22
23
40
41
42
44
63 O/L
BR
GR/W
Y/G
P
L
O
G Fuel injector No. 5
Fuel injector No. 3
Fuel injector No. 1
Fuel injector No. 6
Fuel injector No. 4
Fuel injector No. 2
Fuel injector No. 7
Fuel injector No. 8 [Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm at idle. BATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14V)
PBIB0042E
PBIB0043E

FUEL INJECTOREC-601
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
2. CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine.
2. Perform “POWER BALANCE ” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each fuel injector operating sound. Clicking noise should be heard.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
PBIB0133E
PBIB1986E

EC-602Revision: November 2009
FUEL INJECTOR
2006 QX56
3. CHECK FUEL INJECTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E2, F32

IPDM E/R connector E119

15A fuse

Harness for open or short between fuel injector and fuse
>> Repair harness or connectors.
5. CHECK FUEL INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between fuel injector terminal 2 and ECM terminals 21, 22, 23, 40, 41, 42, 44, 63.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. Voltage: Battery voltage
BBIA0374E
PBIB0582E
Continuity should exist.

FUEL INJECTOREC-603
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
6. CHECK FUEL INJECTOR
Refer to EC-603, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace fuel injector.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionUBS00L1J
FUEL INJECTOR
1. Disconnect fuel injector harness connector.
2. Check resistance between terminals as shown in the figure.
Removal and InstallationUBS00L1K
FUEL INJECTOR
Refer to EM-31, "FUEL INJECTOR AND FUEL TUBE" .
Resistance: 11.1 - 14.5
Ω [at 10 - 60 °C (50 - 140 °F)]
PBIB1727E

EC-604Revision: November 2009
FUEL PUMP
2006 QX56
FUEL PUMPPFP:17042
DescriptionUBS00HDB
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump
relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDC
Specification data are reference values.
SensorInput signal to ECMECM FunctionActuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown above Sto ps.
BBIA0402E
MONITOR ITEMCONDITION SPECIFICATION
FUEL PUMP RLY

For 1 second after turning ignition switch ON

Engine running or cranking ON

Except above conditions
OFF