width INFINITI QX56 2009 Factory Service Manual

QUICK REFERNCE CHART: QX56
2010
*2: Verify the vehicle height. If vehicle height is not within ± 10 mm (0.39 in) of the specification, perform the control unit initialization pro-
cedure.
Brake SpecificationsINFOID:0000000005987157
Unit: mm (in)
Brake PedalINFOID:0000000005987158
Unit: mm (in)
CAUTION:
When equipped with adjustable pedal, the pedal must be in th e forward most position (closest to the floor) for pedal height
adjustment. Front brake Brake model AD41VA
Rotor outer diameter × thickness 350 x 30 (13.78 x 1.181)
Pad Length × width × thickness 151.6 x 56.5 x 12.0 (5.97 x 2.22 x 0.476)
Cylinder bore diameter 50.8 (2.00)
Rear brake Brake model AD14VE Rotor outer diameter × thickness 320 x 14 (12.60 x 0.551)
Pad Length × width × thickness 83.0 x 33.0 x 12.0 (3.268 x 1.299 x 0.472)
Cylinder bore diameter 48 (1.89)
Control valve Valve model Electric brake force distribution
Brake booster Booster model C215T
Diaphragm diameter 215 (8.46)
Pedal free height (H) with pedal in forward most position 182.3 - 192.3 (7.18 - 7.57)
Pedal travel (T) 153.3 (6.04)
Stop lamp switch and ASCD cancel switch threaded end to brake pedal bracket gap 0.74 - 1.96 (0.029 - 0.077)
ALFIA0149ZZ

AV
DVD PLAYERAV-153
< ECU DIAGNOSIS > [AUDIO SYSTEM]
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DVD PLAYER
Reference ValueINFOID:0000000003776897
PHYSICAL VALUES
ALNIA0665GB
Te r m i n a l
(Wire color) Description
ConditionReference value
(Approx.)
+ – Signal nameInput/
Output
1
(W) 2
(B) DVD audio signal LH Output Ignition
switch ON With operation of the DVD
player
3—Shield —— — —
5
(B) Ground Ground
—Ignition
switch
ON —0
V
6
(BR) Ground Illumination control (pulse
width modulated)
— — With lighting switch ON
—
7
(W/L) Ground Can communication Input/
Output Ignition
switch ON ——
9
(SB) Ground Video monitor power sup-
ply OutputIgnition
switch ON With DVD player operation
Battery voltage
10
(G/Y) Ground Switch power
OutputIgnition
switch
ON With DVD player operation
5V
12
(B/W) Ground VTR (+)
OutputIgnition
switch ON With DVD player operation
—
13
(L) Ground VTR (-)
OutputIgnition
switch ON With DVD player operation
—
14
(B/W) Ground Display ground
—Ignition
switch
ON With DVD player operation
0V
16
(Y) — Data receive
Input —— —
SKIB3609E
Revision: December 20092009 QX56

SERVICE DATA AND SPECIFICATIONS (SDS)BR-45
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SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
General SpecificationINFOID:0000000004181524
Unit: mm (in)
Brake PedalINFOID:0000000004181525
Unit: mm (in)
CAUTION:
When equipped with adjustable pedal, the pedal must be in the forward most position (closest to the floor) for pedal height
adjustment. Front brake Brake model
AD41VA
Rotor outer diameter × thickness 350 x 30 (13.78 x 1.181)
Pad Length × width × thickness 151.6 x 56.5 x 12.0 (5.97 x 2.22 x 0.476)
Cylinder bore diameter 50.8 (2.00)
Rear brake Brake model AD14VE
Rotor outer diameter × thickness 320 x 14 (12.60 x 0.551)
Pad Length × width × thickness 83.0 x 33.0 x 12.0 (3.268 x 1.299 x 0.472)
Cylinder bore diameter 48 (1.89)
Control valve Valve model Electric brake force distribution
Brake booster Booster model C215T
Diaphragm diameter 215 (8.46)
Recommended brake fluid Refer to MA-12, "
Fluids and Lubricants".
Pedal free height (H) with pedal in forward most position 182.3 - 192.3 (7.18 - 7.57)
Pedal travel (T) 153.3 (6.04)
Stop lamp switch and ASCD cancel switch threaded end to brake pedal bracket gap 0.74 - 1.96 (0.029 - 0.077)
ALFIA0149ZZ
Revision: December 20092009 QX56

CHG
POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM
CHG-7
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POWER GENERATION VOLTAG
E VARIABLE CONTROL SYSTEM
System DiagramINFOID:0000000003776545
System DescriptionINFOID:0000000003776546
Power generation variable voltage control system has been adopted. By varying the voltage to the generator,
engine load due to power generation of the generator is reduced and fuel consumption is decreased.
NOTE:
When any malfunction is detected in the power generat ion variable voltage control system, power generation
is performed according to the characterist ic of the IC regulator in the generator.
Component DescriptionINFOID:0000000003776547
ALMIA0057GB
Component part Description
Battery current sensor The battery current sensor is installed on the battery cable at the
negative terminal. The battery current sensor detects the charg-
ing/discharging current of the battery and sends a voltage signal
to the ECM according to the current value detected.
ECM The battery current sensor detects the charging/discharging cur-
rent of the battery. The ECM judges the battery condition based on
this signal.
The ECM judges whether to request more output via the power
generation voltage variable control according to the battery condi-
tion.
When performing the power generation voltage variable control,
the ECM calculates the target power generation voltage according
to the battery condition and sends the calculated value as the pow-
er generation command value to the IPDM E/R.
IPDM E/R The IPDM E/R converts the received power generation command
value into a pulse width modulated (PWM) command signal and
sends it to the IC regulator.
Generator (IC regulator) The IC regulator controls the power generation voltage by the tar-
get power generation voltage based on the received PWM com-
mand signal.
When there is no PWM command signal, the generator performs
the normal power generation according to the characteristic of the
IC regulator.
Revision: December 20092009 QX56

MULTIPORT FUEL INJECTION SYSTEMEC-29
< FUNCTION DIAGNOSIS > [VK56DE]
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MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov
ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better r educe CO, HC and NOx emissions. This system uses air
fuel ratio (A/F) sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about air
fuel ratio (A/F) sensor 1, refer to EC-136
. This maintains the mixture ratio within the range of stoichiometric
(ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the th ree way catalyst (manifold). Even if the switching
characteristics of air fuel ratio (A/F) sensor 1 shift, t he air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
 Deceleration and acceleration
 High-load, high-speed operation
 Malfunction of A/F sensor 1 or its circuit
 Insufficient activation of A/F sensor 1 at low engine coolant temperature
 High engine coolant temperature
 During warm-up
 After shifting from N to D
 When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM cont rols the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mi xture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value co mpared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensati on used to maintain the mixture ratio at its theoretical
value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in
fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation ca rried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB3020E
Revision: December 20092009 QX56

EC-30
< FUNCTION DIAGNOSIS >[VK56DE]
MULTIPORT FUEL INJECTION SYSTEM
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycl
e according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all eight cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The eight fuel injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speed.
PBIB0122E
Revision: December 20092009 QX56

ELECTRIC IGNITION SYSTEMEC-31
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ELECTRIC IGNITION SYSTEM
System DescriptionINFOID:0000000003771304
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Firing order: 1 - 8 - 7 - 3 - 6 - 5 - 4 -2
The ignition timing is controlled by the ECM to maintain
the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Comput-
ing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revi sed by the ECM according to the other data stored in
the ECM.
 At starting
 During warm-up
At idle
 At low battery voltage
 During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
2
Piston position
Ignition timing
controlPower transistor
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
TCM Gear position
Battery
Battery voltage*
2
Wheel sensor
Vehicle speed*1
Revision: December 20092009 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-67
< FUNCTION DIAGNOSIS > [VK56DE]
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*: The item is the same as that of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×
: Applicable
INT/A TEMP SE
[° C] or [ °F]  The intake air temperature at the moment a malfunction is detected is displayed.
INT MANI PRES [kPa]  Always a certain value is displayed.
 These items are not efficient JA60 models.
COMBUST CONDI-
TION Freeze frame data
item* Description
Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description Remarks
ENG SPEED [rpm] ×× Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS) and camshaft position
sensor (PHASE).  Accuracy becomes poor if engine
speed drops below the idle rpm.
 If the signal is interrupted while the en-
gine is running, an abnormal value may
be indicated.
MAS A/F SE-B1 [V] ×× The signal voltage of the mass air flow
sensor is displayed.  When the engine is stopped, a certain
value is indicated.
 When engine is running specification range is indicated in “SPEC”.
B/FUEL SCHDL
[msec] ×× Base fuel schedule indicates the fuel in-
jection pulse width programmed into
ECM, prior to any learned on board cor-
rection.  When engine is running specification
range is indicated in “SPEC”.
A/F ALPHA-B1 [%]  The mean value of the air-fuel ratio feed-back correction factor per cycle is indi-
cated.  When the engine is stopped, a certain
value is indicated.
 When engine is running specification range is indicated in “SPEC”.
 This data also includes the data for the
air-fuel ratio learning control.
A/F ALPHA-B2 [%]
COOLAN TEMP/S
[
° C] or [ °F] ××  The engine coolant temperature (deter-
mined by the signal voltage of the engine
coolant temperature sensor) is dis-
played.  When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine cool-
ant temperature determined by the
ECM is displayed.
A/F SEN1 (B1) [V] ××
 The A/F signal computed from the input
signal of the A/F sensor 1 is displayed.
A/F SEN1 (B2) [V] ××
HO2S2 (B1) [V] ××
 The signal voltage of the heated oxygen
sensor 2 is displayed.
HO2S2 (B2) [V] ××
HO2S2 MNTR (B1)
[RICH/LEAN] ×
 Display of heated oxygen sensor 2 sig-
nal:
RICH: means the amount of oxygen after
three way catalyst is relatively small.
LEAN: means the amount of oxygen af-
ter three way catalyst is relatively large. When the engine is stopped, a certain
value is indicated.
HO2S2 MNTR (B2)
[RICH/LEAN] ×
VHCL SPEED SE
[km/h] or [mph] ×× The vehicle speed computed from the
vehicle speed signal sent from combina-
tion meter is displayed.
BATTERY VOLT [V]  The power supply voltage of ECM is dis-
played.
ACCEL SEN 1 [V]  The accelerator pedal position sensor
signal voltage is displayed.  ACCEL SEN 2 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal.
ACCEL SEN 2 [V]
Revision: December 20092009 QX56

EC-68
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
TP SEN 1-B1 [V]
××
 The throttle position sensor signal volt-
age is displayed.  TP SEN 2-B1 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal.
TP SEN 2-B1 [V]
××
FUEL T/TMP SE
[ ° C] or [ °F]  The fuel temperature (determined by the
signal voltage of the fuel tank tempera-
ture sensor) is displayed.
INT/A TEMP SE
[ ° C] or [ °F] ××  The intake air temperature (determined
by the signal voltage of the intake air
temperature sensor) is indicated.
EVAP SYS PRES
[V]  The signal voltage of EVAP control sys-
tem pressure sensor is displayed.
FUEL LEVEL SE [V] × The signal voltage of the fuel level sen-
sor is displayed.
START SIGNAL
[ON/OFF]  Indicates start signal status [ON/OFF]
computed by the ECM according to the
signals of engine speed and battery volt-
age.  After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF] ×× Indicates idle position [ON/OFF] comput-
ed by ECM according to the accelerator
pedal position sensor signal.
AIR COND SIG
[ON/OFF] ×× Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF] ××
 Indicates [ON/OFF] condition from the
transmission range signal.
PW/ST SIGNAL
[ON/OFF] ×× [ON/OFF] condition of the power steering
system (determined by the signal voltage
of the power steering pressure sensor
signal) is indicated.
LOAD SIGNAL [ON/
OFF] ×× Indicates [ON/OFF] condition from the
electrical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
IGNITION SW
[ON/OFF] ×× Indicates [ON/OFF] condition from igni-
tion switch signal.
HEATER FAN SW
[ON/OFF] ×
 Indicates [ON/OFF] condition from heat-
er fan switch signal.
BRAKE SW
[ON/OFF]  Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec]  Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.  When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING [BT-
DC]  Indicates the ignition timing computed by
ECM according to the input signals.  When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE [%]
 “Calculated load value” indicates the val- ue of the current air flow divided by peak
air flow.
MASS AIRFLOW
[g·m/s]  Indicates the mass air flow computed by
ECM according to the signal voltage of
the mass air flow sensor.
Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description Remarks
Revision: December 20092009 QX56

EC-74
< COMPONENT DIAGNOSIS >[VK56DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
COMPONENT DIAGNOSIS
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000003771320
The specification (SP) value indicates the tolerance of
the value that is displayed in “SPEC” of “DATA MONI-
TOR” mode with CONSULT-III during normal operation of the Engine Control System. When the value in
“SPEC” of “DATA MONITOR” mode is within the SP value, the Engine Control System is confirmed OK. When
the value in “SPEC” of “DATA MONITOR” mode is NO T within the SP value, the Engine Control System may
have one or more malfunctions.
The SP value is used to detect malfunctions that may af fect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
 B/FUEL SCHDL (The fuel injection pulse width progr ammed into ECM prior to any learned on board correc-
tion)
 A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
 MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionINFOID:0000000003771321
 Vehicle driven distance: More than 5,000 km (3,107 miles)
 Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm
2 , 14.25 - 15.12 psi)
 Atmospheric temperature: 20 - 30 °C (68 - 86 °F)
 Engine coolant temperature: 75 - 95 °C (167 - 203 °F)
 Engine speed: Idle
 Transmission: Warmed-up
- After the engine is warmed up to normal operating temper ature, drive vehicle until “ATF TEMP SE 1” (A/T
fluid temperature sensor signal) indicates more than 60 °C (140 °F).
 Electrical load: Not applied
- Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureINFOID:0000000003771322
NOTE:
Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.
1. Perform EC-13, "Basic Inspection"
.
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2” and “MAS A/F SE-B1” in “SPEC” of “DATA
MONITOR” mode with CONSULT-III.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-75, "Diagnosis Procedure"
.
Revision: December 20092009 QX56