heater INFINITI QX56 2006 Factory Owners Manual

EC-470Revision: November 2009
DTC P1148, P1168 CLOSED LOOP CONTROL
2006 QX56
DTC P1148, P1168 CLOSED LOOP CONTROLPFP:22690
On Board Diagnosis LogicUBS00H8K
These self-diagnoses have the one trip detection logic.
DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.
Perform the trouble diagnosis for the corresponding DTC.
DTC No. Trouble diagnosis nameDTC detecting condition Possible cause
P1148
1148
(Bank 1) Closed loop control
function The closed loop control function for bank 1
does not operate even when vehicle is driving
in the specified condition.

Harness or connectors
[The air fuel ratio (A/F) sensor 1 circuit is
open or shorted.]

Air fuel ratio (A/F) sensor 1

Air fuel ratio (A/F) sensor 1 heater
P1168
1168
(Bank 2) The closed loop control function for bank 2
does not operate even when vehicle is driving
in the specified condition.

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)

EC-578Revision: November 2009
DTC P2A00, P2A03 A/F SENSOR 1
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.)TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
2 O/B A/F sensor 1 heater
(bank 1) [Engine is running]

Warm-up condition

Idle speed Approximately 5V
16 BR/R A/F sensor 1 (bank 1) [Engine is running]

Warm-up condition

Idle speed Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
PBIB1584E

EC-580Revision: November 2009
DTC P2A00, P2A03 A/F SENSOR 1
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 ProcedureUBS00N7I
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body. Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
24 BR/W A/F sensor 1 heater
(bank 2) [Engine is running]

Warm-up condition

Idle speed Approximately 5V
57 L/P A/F sensor 1 (bank 2) [Engine is running]

Warm-up condition

Idle speed Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
PBIB1584E
BBIA0354E

EC-584Revision: November 2009
DTC P2A00, P2A03 A/F SENSOR 1
2006 QX56
8. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows. Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK A/F SENSOR 1 HEATER
Refer to EC-162, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 11.
10. CHECK INTERMITTENT INCIDENT
Perform EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 11.
NG >> Repair or replace.
A/F sensor 1 terminal ECM terminal
Bank1 11
6
27 5
53 5
65 6
Bank 2 17
6
27 7
55 7
65 8
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 11 617 6
27 527 7
53 555 7
65 665 8
Continuity should not exist.

EC-596Revision: November 2009
ELECTRICAL LOAD SIGNAL
2006 QX56
ELECTRICAL LOAD SIGNALPFP:25350
DescriptionUBS00HDL
The electrical load signal (Headlamp switch signal, rear window defogger switch signal, etc.) is transferred
through the CAN communication line from BCM to ECM via IPDM E/R.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDM
Specification data are reference values.
Diagnostic ProcedureUBS00HDN
1. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
1. Turn ignition switch ON.
2. Connect CONSULT-II and select “DATA MONITOR ” mode.
3. Select “LOAD SIGNAL ” and check indication under the following
conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II
Check “LOAD SIGNAL ” indication under the following conditions.
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
MONITOR ITEM CONDITION SPECIFICATION
LOAD SIGNAL

Ignition switch: ON Rear window defogger switch is ON
and/or lighting switch is in 2nd.
ON
Rear window defogger switch is OFF
and lighting switch is OFF. OFF
HEATER FAN SW

Engine: After warming up, idle
the engine Heater fan control switch: ON
ON
Heater fan control switch: OFF OFF
Condition Indication
Rear window defogger switch: ON ON
Rear window defogger switch: OFF OFF
PBIB0103E
ConditionIndication
Lighting switch: ON at 2nd position ON
Lighting switch: OFF OFF
PBIB0103E

ELECTRICAL LOAD SIGNALEC-597
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Revision: November 2009 2006 QX56
3. CHECK HEATER FAN SIGNAL CIRCUIT OVERALL FUNCTION
Select “HEATER FAN SW ” and check indication under the following
conditions.
OK or NG
OK >> INSPECTION END
NG >> GO TO 6.
4. CHECK REAR WINDOW DEFOGGER SYSTEM
Refer to GW-74, "
REAR WINDOW DEFOGGER" .
>> INSPECTION END
5. CHECK HEADLAMP SYSTEM
Refer to LT- 5 , "
HEADLAMP (FOR USA)" , or LT- 3 3 , "HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYS-
TEM -" .
>> INSPECTION END
6. CHECK HEATER FAN CONTROL SYSTEM
Refer to GW-74, "
REAR WINDOW DEFOGGER" .
>> INSPECTION END
Condition Indication
Heater fan control switch: ON ON
Heater fan control switch: OFF OFF
PBIB0103E

SERVICE DATA AND SPECIFICATIONS (SDS)EC-637
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Revision: November 2009 2006 QX56
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureUBS00HE9
Idle Speed and Ignition TimingUBS00HEA
*: Under the following conditions:

Air conditioner switch: OFF

Electric load: OFF (Lights and heater fan)

Steering wheel: Kept in straight-ahead position
Calculated Load ValueUBS00HEB
Mass Air Flow SensorUBS00HEC
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature SensorUBS00HED
Engine Coolant Temperature SensorUBS00HEE
A/F Sensor 1 HeaterUBS00HEF
Heated Oxygen sensor 2 HeaterUBS00HEG
Crankshaft Position Sensor (POS)UBS00HEH
Refer to EC-346, "Component Inspection" .
Camshaft Position Sensor (PHASE)UBS00HEI
Refer to EC-353, "Component Inspection" .
Throttle Control MotorUBS00HEJ
Fuel pressure at idling kPa (kg/cm2 , psi) Approximately 350 (3.57, 51)
Target idle speed
No-load* (in P or N position) 650±50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 15° ± 5 ° BTDC
Condition Calculated load value % (Using CONSULT-II or GST)
At idle 14.0 - 33.0
At 2,500 rpm 12.0 - 25.0
Supply voltageBattery voltage (11 - 14V)
Output voltage at idle 1.0 - 1.3V*
Mass air flow (Using CONSULT-II or GST) 3.0 - 9.0 g
·m/sec at idle*
9.0 - 28.0 g· m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77) 1.800 - 2.200
Temperature °C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Resistance [at 25°C (77 °F)] 2.3 - 4.3Ω
Resistance [at 25 °C (77 °F)] 5.0 - 7.0Ω
Resistance [at 25 °C (77 °F)] Approximately 1 - 15Ω

EM-38Revision: November 2009
TIMING CHAIN
2006 QX56
NOTE:

To remove timing chain and associated parts, start with those on the LH bank. The procedure for remov-
ing parts on the RH bank is omitted because it is the same as that for removal on the LH bank.

To install timing chain and associated parts, start with those on the RH bank. The procedure for installing
parts on the LH bank is omitted because it is the same as that for installation on the RH bank.
REMOVAL
1. Remove the engine assembly from the vehicle. Refer to EM-74, "REMOVAL" .
2. Remove the following components and related parts:

Drive belt auto tensioner and idler pulley. Refer to EM-13, "REMOVAL" .

Thermostat housing and water hose. Refer toCO-21, "Removal of Thermostat Housing, Water Outlet
and Heater Pipe" .

Power steering oil pump bracket. Refer to PS-21, "REMOVAL" .

Oil pan (lower), (upper) and oil strainer. Refer to EM-24, "REMOVAL" .

Ignition coil. Refer to EM-28, "REMOVAL" .

Rocker cover. Refer to EM-35, "REMOVAL" .
3. Remove the chain case cover RH bank (A) and chain case cover LH bank (B) as follows:
a. Loosen and remove the bolts as shown.
b. Cut the liquid gasket and remove the covers using Tool.
CAUTION:
Do not damage mating surfaces.
4. Obtain compression TDC of No. 1 cylinder as follows:
a. Turn the crankshaft pulley clockwise to align the TDC identifica- tion notch (without paint mark) with the timing indicator on the
front cover.
1. Camshaft sprocket LH bank EXH 2. Camshaft sprocket LH bank INT 3. Camshaft sprocket RH bank INT
4. Camshaft sprocket RH bank EXH 5. Front cover 6. Chain case cover RH bank
7. Chain case cover LH bank 8. Crankshaft pulley bolt 9. Crankshaft pulley
10. Chain tensioner cover 11. Front oil seal 12. Oil pump drive spacer
13. Oil pump assembly 14. Crankshaft sprocket 15. Bracket
16. O-ring 17. Timing chain tension guide RH bank 18. Timing chain slack guide RH bank
19. Timing chain RH bank 20. Timing chain LH bank 21. Chain tensioner RH bank
22. Timing chain slack guide LH bank 23. Timing chain tension guide LH bank 24. Chain tensioner LH bank
Tool number : KV10111100 (J-37228)
WBIA0698E
KBIA2476E

ENGINE ASSEMBLYEM-75
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Revision: November 2009 2006 QX56
4. Remove the engine hood. Refer to BL-13, "Removal and Installation of Hood Assembly" .
5. Remove the cowl extension. Refer to EI-18, "
Removal and Installation" .
6. Remove the engine room cover using power tools.
7. Remove the air duct and air cleaner case assembly. Refer to EM-15, "
Removal and Installation" .
8. Disconnect the vacuum hose between the vehicle and engine and set it aside.
9. Remove the radiator assembly and hoses. Refer to CO-14, "
Removal and Installation" .
10. Remove the drive belts. Refer to EM-13, "
Removal and Installation" .
11. Remove the fan blade. Refer to CO-17, "
Removal and Installation (Crankshaft Driven Type)" .
12. Disconnect the engine room harness from the fuse box and set it aside.
13. Disconnect the ECM.
14. Disconnect the engine room harness from the engine side and set it aside.
15. Disconnect the engine harness grounds.
16. Disconnect the power steering reservoir tank from the engine and move it aside.
17. Disconnect the power steering oil pump from the engine. Move it aside and secure it using suitable wire or rope. Refer to PS-21, "
Removal and Installation" .
18. Remove the A/C compressor bolts and set the compressor aside. Refer to ATC-175, "
Removal and Instal-
lation for Compressor" (ATC).
19. Disconnect the brake booster vacuum line.
20. Disconnect the EVAP line.
21. Disconnect the fuel hose at the engine side connection. Refer to EM-31, "
Removal and Installation" .
22. Disconnect the heater hoses at the cowl, and install plugs to avoid leakage of engine coolant.
23. Remove the A/T oil level indicator and indicator tube upper bolts.
24. Remove the front final drive assembly (4WD only). Refer to FFD-12, "
Removal and Installation" .
25. Remove the exhaust manifolds. Refer to EM-21, "
Removal and Installation" .
26. Install the engine slingers into the left bank cylinder head and right bank cylinder head.
27. Remove the A/T. Refer to AT- 2 4 3 , "
Removal and Installation
(2WD)" or AT- 2 4 6 , "Removal and Installation (4WD)" .
28. Lift using a hoist and secure the engine in position.
29. Remove the engine assembly from the vehicle, avoid interfer- ence with the vehicle body.
CAUTION:

Before and during lifting, always check if any harnesses
are left connected.
30. Remove the parts that may restrict installation of the engine to the engine stand.
NOTE:
This procedure is described assuming that you use an engine stand mounting to the surface to which the
transmission mounts.
a. Remove the drive plate.

Holding the crankshaft pulley bolt, lock the crankshaft to remove the drive plate bolts.
WBIA0464E
Engine slinger torque: 45.0 N·m (4.6 kg-m, 33 ft-lb)
WBIA0715E