2009 INFINITI QX56 fuel pressure

RSU-6
< ON-VEHICLE MAINTENANCE >
REAR SUSPENSION ASSEMBLY
ON-VEHICLE MAINTENANCE
REAR SUSPENSION ASSEMBLY
On-Vehicle Inspection and ServiceINFOID:0000000003772290
Check all of the component mountings for any excessive looseness, or back lash. Check the components for
any excessive wear, damage, or abnormal conditions. Repair or replace the components as necessary.
SHOCK ABSORBER INSPECTION
 Check the shock absorbers for any air l eaks or damage, and replace as necessary.
 Check the hoses for any air leaks or damage, and replace as necessary.
Wheel AlignmentInspectionINFOID:0000000005889867
Rear Wheel Alignment Adjusting Bolts
PRELIMINARY INSPECTION
WARNING:
Always adjust the alignm ent with the vehicle on a flat su rface. Use CONSULT-III “EXHAUST SOLE-
NOID” active test to release the air pressure from the rear load leveling air suspension system.
NOTE:
If alignment is out of specificat ion, inspect and replace any damaged or worn rear suspension parts before
making any adjustments.
1. Check and adjust the wheel alignment with the vehicle under unladen conditions. “Unladen conditions”
means that the fuel, coolant, and lubricant are full; and that the spare tire, jack, hand tools and mats are in
their designated positions.
2. Check the tires for incorrect air pressure and excessive wear.
3. Check the wheels for runout and damage.
4. Check the wheel bearing axial end play.
5. Check the shock absorbers. Refer to RSU-6, "On-Vehicle Inspection and Service"
.
6. Check each mounting point of the suspension components for any excessive looseness or damage.
7. Check each link, arm, and the rear suspension member for any damage.
8. Check the vehicle height. Refer to RSU-29, "Wheel Alignment (Unladen
*1)" .
WEIA0102E
1. Rear lower link adjusting bolt, LH 2. Front lower link adjusting bolt, LH 3. Front lower link adjusting bolt, RH
4. Rear lower link adjusting bolt, RH
Axial end play : 0 mm (0 in)
Revision: December 20092009 QX56

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
SEC-101
< ECU DIAGNOSIS > [WITH INTELLIGENT KEY SYSTEM]
C
D
E
F
G H
I
J
L
M A
B
SEC
N
O P
41 Y/B Hood switch Input —Hood closed OFF
0V
Hood open ON Battery voltage
42 GR Oil pressure switch Input — Engine running
Battery voltage
Engine stopped 0V
43 L/Y Wiper auto stop signal Input ON or
START Wiper switch OFF, LO, INT Battery voltage
44 BR Daytime light relay
control Input ONDaytime light system active
0V
Daytime light system inactive Battery voltage
45 G/W Horn relay control Input ON When door locks are operated
using keyfob or Intelligent Key
(OFF
→ ON)* Battery voltage
→ 0V
46 GR Fuel pump relay con-
trol
Input —Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
47 O Throttle control motor
relay control
Input —Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
48 B/R Starter relay (inhibit
switch) InputON or
START Selector lever in "P" or "N"
0V
Selector lever any other posi-
tion Battery voltage
49 R/L Trailer tow relay Output ON Lighting
switch must
be in the 1st
positionOFF
0V
ON Battery voltage
50 W/R Front fog lamp (LH) Output ON or
START Lighting
switch must
be in the 2nd
position
(LOW beam
is ON) and
the front fog
lamp switch OFF
0V
ON Battery voltage
51 W/R Front fog lamp (RH) Output ON or
START Lighting
switch must
be in the 2nd
position
(LOW beam
is ON) and
the front fog
lamp switch OFF
0V
ON Battery voltage
52 L LH low beam head-
lamp Output — Lighting switch in 2nd position Battery voltage
54 R/Y RH low beam head-
lamp Output — Lighting switch in 2nd position Battery voltage
55 G LH high beam head-
lamp Output —Lighting switch in 2nd position
and placed in HIGH or PASS
position Battery voltage
56 L/W RH high beam head-
lamp Output —Lighting switch in 2nd position
and placed in HIGH or PASS
position Battery voltage
57 R/L Parking, license, and
tail lamp
Output ONLighting
swi
t

ch 1st po-
sition OFF
0V
ON Battery voltage
Te r m i n a l
Wire
color Signal name Signal
input/
output Measuring condition
Reference value(Approx.)
Igni-
tion
switch Operation or condition
Revision: December 20092009 QX56

STR-10
< COMPONENT DIAGNOSIS >
B TERMINAL CIRCUIT
COMPONENT DIAGNOSIS
B TERMINAL CIRCUIT
DescriptionINFOID:0000000003771792
Terminal "2" (B) is constantly supplied with battery power.
Diagnosis ProcedureINFOID:0000000003771793
CAUTION:
Perform diagnosis under the condition that the engine cannot start by the following procedure.
1. Remove fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is depleted.
1.CHECK TERMINAL 2 POWER SUPPLY VOLTAGE
1. Turn ignition switch OFF.
2. Make sure that starter motor connector F27 terminal 2 connection is clean and tight.
3. Check voltage between starter motor connector F27 terminal 2
and ground.
Is there battery voltage present?
YES >> GO TO 2
NO >> Check harness between battery and starter motor for open circuit.
2.CHECK BATTERY CABLE (VOLTAGE DROP TEST)
1. Shift the transmission into park or neutral.
2. Check voltage between battery positive terminal and starter motor connector F27 terminal 2 while cranking the engine.
Is the voltage drop less than 0.2V?
YES >> GO TO 3
NO >> Check harness between the battery and the starter motor for high resistance.
3.CHECK GROUND CIRCUIT STATUS (VOLTAGE DROP TEST)
Check voltage between starter motor case and battery negative ter-
minal while cranking the engine.
Is the voltage drop less than 0.2V?
YES >> Terminal 2 circuit is OK. Further inspection necessary. Refer to STR-5, "
Work Flow".
NO >> Check the starter motor case to engine mounting for high resistance.
(+) (-)Condition Voltage
Connector Terminal
F27 2 Ground While cranking the
engine Battery voltage
AWBIA0122GB
(+)
(-)Condition Voltage
Connector Terminal
F27 2 Battery (+)
terminal While cranking the
engine Less than 0.2V
AWBIA0123GB
(+)
(-)Condition Voltage
Starter motor case Battery (-) terminal
While cranking the
engine Less than 0.2V
AWBIA0124GB
Revision: December 20092009 QX56

S CONNECTOR CIRCUITSTR-11
< COMPONENT DIAGNOSIS >
C
DE
F
G H
I
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K L
M A
STR
NP
O
S CONNECTOR CIRCUIT
DescriptionINFOID:0000000003771794
Terminal "1" (S) is the power supply for the starter mo
tor magnetic switch. Terminal 1 is supplied with power
when the ignition switch is turned to the START position while the selector lever is in the P or N position.
Diagnosis ProcedureINFOID:0000000003771795
CAUTION:
Perform diagnosis under the cond ition that engine cannot start by the following procedure.
1. Remove fuel pump fuse.
2. Crank or start the engine (where possi ble) until the fuel pressure is released.
1.CHECK STARTER MOTOR MAGNETIC SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect starter motor connector F28.
3. Shift transmission into park or neutral.
4. Check voltage between starter motor harness connector F28 terminal 1 and ground with the ignition switch in START.
Is battery voltage present?
YES >> Magnetic switch circuit is OK. Further inspection necessary. Refer to STR-5, "Work Flow".
NO >> GO TO 2
2.CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Check the IPDM E/R harness connector E120 and starter motor harness connector F28 for damage, bent pins and loose connections.
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair the terminal and connector.
3.CHECK HARNESS CONTI NUITY (OPEN CIRCUIT)
1. Disconnect IPDM E/R connector E120 and starter motor con- nector F28.
2. Check continuity between starter motor harness connector F28 (A) terminal 1 and IPDM E/R harness connector E120 (B) termi-
nal 19.
3. Check continuity between starter motor harness connector F28 (A) terminal 1 and ground.
Are the continuity test results as specified?
YES >> Further inspection necessary. Refer to STR-5, "Work Flow".
NO >> Repair the harness.
(+) (-)Condition Voltage
Connector Terminal
F28 1 Ground Ignition switch in
START Battery voltage
AWBIA0125GB
AB
Continuity
Connector Terminal Connector Terminal
F28 1E120 19 Yes
A —Con tin uit y
Connector Terminal
F28 1Ground No
AWBIA0126GB
Revision: December 20092009 QX56

TM-26
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In th is way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-clutched State
 The current output from the TCM to the torque converte r clutch solenoid is varied to gradually increase the
torque converter clutch solenoid pressure.
In this way, the lock-up apply pressure gradually rises and while the torque converter clutch piston is put into
half-clutched status, the torque converter clutch pi ston operating pressure is increased and the coupling is
completed smoothly.
Slip Lock-up Control
 In the slip region, the torque converter clutch solenoid current is controlled with the TCM to put it into the
half-clutched state. This absorbs the engine tor que fluctuation and lock-up operates from low speed.
This raises the fuel efficiency for 4GR and 5GR at both low speed and when the accelerator has a low
degree of opening.
Engine Brake ControlINFOID:0000000003771814
 The forward one-way clutch transmits the drive force from the engine to the rear wheels. But the reverse
drive from the rear wheels is not transmitted to the engine because the one-way clutch is idling.
Therefore, the low coast brake solenoid is operated to prevent the forward one-way clutch from idling and
the engine brake is operated in the same manner as conventionally.
 The operation of the low coast brake solenoid switches the low coast brake switching valve and controls the
coupling and releasing of the low coast brake.
The low coast brake reducing valve contro ls the low coast brake coupling force.
Control ValveINFOID:0000000003771815
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
Torque converter regulator valve In order to prevent the pressure supplied to the torque converter from being excessive,
the line pressure is adjusted to the optimum pressure (torque converter operating pres-
sure).
Pressure regu lator valve
Pressure regulator plug
Pressure regu lator sleeve Adjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valve When the front brake is coupled, adjusts the line pressure to the optimum pressure (front
brake pressure) and supplies it to the front brake. (In 1GR, 2GR, 3GR, and 5GR, adjusts
the clutch pressure.)
Accumulator control valve Adjusts the pressure (accumulator control pressure) acting on the accumulator piston
and low coast reducing valve to the pressure appropriate to the driving state.
Revision: December 20092009 QX56

WCS-12
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (METER)
DIAGNOSIS SYSTEM (METER)
CONSULT-III Function (METER/M&A)INFOID:0000000004115456
CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.
SELF-DIAG RESULTS
Display Item List
Refer to WCS-47, "DTC Index".
DATA MONITOR
Display Item List
X: Applicable
METER/M&A diagnosis mode Description
SELF-DIAG RESULTS Displays combination meter self-diagnosis results. DATA MONITOR Displays combination meter input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
Display item [Unit] MAIN
SIGNALS SELECTION
FROM MENU Description
SPEED METER [km/h] or [mph] X X Displays the value of vehicle speed signal.
SPEED OUTPUT [km/h] or [mph] X XDisplays the value of vehicle speed signal, which is transmitted to
each unit with
CAN communication.
TACHO METER [rpm] XX Displays the value of engine speed signal, which is input from ECM.
FUEL METER [lit.] XXDisplays the value, which processes a resistance signal from fuel
gauge.
W TEMP METER [ °C] or [° F] X XDisplays the value of engine coolant temperature signal, which is in-
put from ECM.
ABS W/L [ON/OFF] X Displays [ON/OFF] condition of ABS warning lamp.
VDC/TCS IND [ON/OFF] X Displays [ON/OFF] condition of VDC OFF indicator lamp.
SLIP IND [ON/OFF] X Displays [ON/OFF] condition of SLIP indicator lamp.
BRAKE W/L [ON/OFF] X Displays [ON/OFF] condition of brake warning lamp.*
DOOR W/L [ON/OFF] X Displays [ON/OFF] condition of door warning lamp.
TRUNK W/L [ON/OFF] X Displays [ON/OFF] condition of glass hatch warning lamp.
HI-BEAM IND [ON/OFF] X Displays [ON/OFF] condition of high beam indicator.
TURN IND [ON/OFF] X Displays [ON/OFF] conditio n of turn indicator.
OIL W/L [ON/OFF] X Displays [ON/OFF] condition of oil pressure warning lamp.
C-ENG W/L [ON/OFF] X Displays [ON/OFF] condition of malfunction indicator lamp.
CRUISE IND [ON/OFF] X Displays [ON/OFF] condition of CRUISE indicator.
SET IND [ON/OFF] X Displays [ON/OFF] condition of SET indicator.
AT CHECK W/L [ON/OFF] X Displays [ON/OFF] condition of AT CHECK warning lamp.
FUEL W/L [ON/OFF] XX Displays [ON/OFF] condition of low-fuel warning lamp.
AIR PRES W/L [ON/OFF] X Displays [ON/OFF] condition of tire pressure warning lamp.
KEY G W/L [ON/OFF] X Displays [ON/OFF] condition of key green warning lamp.
KEY R W/L [ON/OFF] X Displays [ON/OFF] condition of key red warning lamp.
KEY KNOB W/L [ON/OFF] X Displays [ON/OFF] condition of key knob warning lamp.
M RANGE SW [ON/OFF] XX Displays [ON/OFF] condition of manual mode range switch.
NM RANGE SW [ON/OFF] XXDisplays [ON/OFF] condition of except for manual mode range
switch.
AT SFT UP SW [ON/OFF] XX Displays [ON/OFF] condition of A/T shift-up switch.
Revision: December 20092009 QX56

WCS
COMBINATION METERWCS-47
< ECU DIAGNOSIS >
C
DE
F
G H
I
J
K L
M B A
O P
DTC IndexINFOID:0000000004115463
Function Specifications
Speedometer
Zero indication.
Tachometer
Fuel gauge
Engine coolant temperature gauge
Engine oil pressure gauge
Voltage gauge
A/T oil temperature gauge
Illumination control
Meter illumination Change to nighttime mode when communication is lost.
Segment LCD Odometer
Freeze current indication.
A/T position Display turns off.
Buzzer Buzzer turns off.
Warning lamp/indicator lamp ABS warning lamp
Lamp turns on when communication is lost.
Brake warning lamp
VDC OFF indicator lamp
SLIP indicator lamp
A/T CHECK warning lamp
Lamp turns off when communication is lost.
Oil pressure/coolant temperature
warning lamp
Light indicator
Malfunction indicator lamp
Master warning lamp
Air bag warning lamp
High beam indicator
Turn signal indicator lamp
CRUISE indicator lamp
Driver and passenger seat belt warn-
ing lamp
Lamp turns off when disconnected.
Charge warning lamp
Security indicator lamp
4WD indicator lamp
ATP indicator lamp
CK SUSP warning lamp
Low tire pressu
re warning lamp Lamp will flash every second for 1 minute and then stay on con-
tinuously thereafter.
CONSULT-III display
MalfunctionReference
page
CAN COMM CIRC
[U1000] Malfunction is detected in CAN communication.
CAUTION:
Even when there is no ma
lfunction on CAN communication system, malfunction may be
misinterpreted when battery has low voltag e (when maintaining 7 - 8 V for about 2 sec-
onds) or 10A fuse [No. 19, located in the fuse block (J/B)] is disconnected. MWI-28
VEHICLE SPEED
CIRC
[B2205]Malfunction is detected when an erroneous speed signal is input.
CAUTION:
Even when there is no malfunction on speed signal system, malfunction may be misin-
terpreted when battery has low voltage (whe
n maintaining 7 - 8 V for about 2 seconds). MWI-29
Revision: December 20092009 QX56

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
WW-59
< ECU DIAGNOSIS >
C
D E
F
G H
I
J
K
M A
B
WW
N
O P
41 Y/B Hood switch Input —Hood closed OFF
0V
Hood open ON Battery voltage
42 GR Oil pressure switch Input — Engine running
Battery voltage
Engine stopped 0V
43 L/Y Wiper auto stop signal Input ON or
START Wiper switch OFF, LO, INT Battery voltage
44 BR Daytime light relay
control Input ONDaytime light system active
0V
Daytime light system inactive Battery voltage
45 G/W Horn relay control Input ON When door locks are operated
using keyfob or Intelligent Key
(OFF
→ ON)* Battery voltage
→ 0V
46 GR Fuel pump relay con-
trol
Input —Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
47 O Throttle control motor
relay control
Input —Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
48 B/R Starter relay (inhibit
switch) InputON or
START Selector lever in "P" or "N"
0V
Selector lever any other posi-
tion Battery voltage
49 R/L Trailer tow relay Output ON Lighting
switch must
be in the 1st
positionOFF
0V
ON Battery voltage
50 W/R Front fog lamp (LH) Output ON or
START Lighting
switch must
be in the 2nd
position
(LOW beam
is ON) and
the front fog
lamp switch OFF
0V
ON Battery voltage
51 W/R Front fog lamp (RH) Output ON or
START Lighting
switch must
be in the 2nd
position
(LOW beam
is ON) and
the front fog
lamp switch OFF
0V
ON Battery voltage
52 L LH low beam head-
lamp Output — Lighting switch in 2nd position Battery voltage
54 R/Y RH low beam head-
lamp Output — Lighting switch in 2nd position Battery voltage
55 G LH high beam head-
lamp Output —Lighting switch in 2nd position
and placed in HIGH or PASS
position Battery voltage
56 L/W RH high beam head-
lamp Output —Lighting switch in 2nd position
and placed in HIGH or PASS
position Battery voltage
57 R/L Parking, license, and
tail lamp
Output ONLighting
swi
t

ch 1st po-
sition OFF
0V
ON Battery voltage
Te r m i n a l
Wire
color Signal name Signal
input/
output Measuring condition
Reference value(Approx.)
Igni-
tion
switch Operation or condition
Revision: December 20092009 QX56