2008 INFINITI QX56 Fuel sensor

MWI-42
< ECU DIAGNOSIS >
COMBINATION METER
ECU DIAGNOSIS
COMBINATION METER
Reference ValueINFOID:0000000001691309
TERMINAL LAYOUT
PHYSICAL VALUES
WKIA5724E
Te r m i -nal Wire
color Item Condition
Reference value (V)
(Approx.)
Ignition
switch Operation or condition
3 Y/L Fuel level sensor signal — —Refer to MWI-12, "
FUEL GAUGE : System
Description".
4 B/P Fuel level sensor ground ON —0
6 BR/W Generator ONGenerator voltage low
0
Generator voltage normal Battery voltage
10 L CAN-H —— —
11 P C A N - L —— —
13 P Air bag warning lamp in-
put ONAir bag warning lamp ON
4
Air bag warning lamp OFF 0
15 BR CK SUSP warning lamp
input —CK SUSP warning lamp
ON
0
CK SUSP warning lamp
OFF Battery voltage
20 B Ground —— 0
21 O/L Ignition switch ON or
START ON
— Battery voltage
23 W/L Washer fluid level switch ON Washer fluid level low
0
Washer fluid level normal Battery voltage
24 O/B Seat belt buckle switch
LH ONUnfastened (ON)
0
Fastened (OFF) Battery voltage
25 P/L Seat belt buckle switch
RH ONUnfastened (ON)
0
Fastened (OFF) Battery voltage
31 G Parking brake switch ON Parking brake applied
0
Parking brake released Battery voltage
32 P/B Brake fluid level switch ON Brake fluid level low
0
Brake fluid level normal Battery voltage
33 R/G Stop lamp switch —Brake pedal depressed
Battery voltage
Brake pedal released 0
Revision: March 2010 2008 QX56

MWI-66
< SYMPTOM DIAGNOSIS >
THE FUEL GAUGE POINTER DOES NOT MOVE
SYMPTOM DIAGNOSIS
THE FUEL GAUGE POINTER DOES NOT MOVE
DescriptionINFOID:0000000001691325
Fuel gauge needle will not move from a certain position.
Diagnosis ProcedureINFOID:0000000001691326
1.CHECK COMBINATION METER INPUT SIGNAL
1. Select “METER/M&A” on CONSULT-III.
2. Using “FUEL METER” of “DATA MONITOR”, comp are the monitor value with the fuel gauge reading on
the combination meter. Refer to MWI-33, "
Component Function Check".
Does monitor value match fuel gauge reading?
YES >> GO TO 2
NO >> Replace combination meter. Refer to MWI-76, "
Removal and Installation".
2.CHECK FUEL LEVEL SENSOR SIGNAL CIRCUIT
Check the fuel level sensor signal circuit. Refer to MWI-33, "
DiagnosisProcedure".
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair harness or connector.
3.CHECK FUEL LEVEL SENSOR UNIT
Perform a unit check for the fuel level sensor unit. Refer to MWI-34, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 4
NO >> Replace fuel level sensor unit. Refer to FL-7, "
Removal and Installation".
4.CHECK FLOAT INTERFERENCE
Check that the float arm does not interfere or bi nd with any of the components in the fuel tank.
Is the inspection result normal?
YES >> Replace combination meter. Refer to MWI-76, "Removal and Installation".
NO >> Repair or replace malfunctioning parts.
Revision: March 2010 2008 QX56

PCS-6
< FUNCTION DIAGNOSIS >[IPDM E/R]
RELAY CONTROL SYSTEM
System Description
INFOID:0000000001696481
IPDM E/R activates the internal cont rol circuit to perform the relay ON-OFF control according to the input sig-
nals from various sensors and the request signals received from control units via CAN communication.
CAUTION:
IPDM E/R integrated relays cannot be removed.
Control relay Input/outputTransmit unitControl partReference
page
Front fog lamp relay Front fog lamp request signal BCM (CAN) Front fog lampsEXL-15
• Headlamp high relay
• Headlamp low relay • High beam request signal
• Low beam request signal
BCM (CAN)• Headlamp high
• Headlamp lowEXL-7
EXL-7
Tail lamp relay
Position light request signal BCM (CAN) •Parking lamps
• License plate lamps
• Tail lamps
• Trailer tow relay
• Illumination systemEXL-18
• Front wiper relay
• Front wiper high relay
Front wiper request signal BCM (CAN)
Front wiper motorWW-4
Rear window defogger re-
lay Rear window defogger re-
quest signal
BCM (CAN)
Rear window defoggerWW-8
A/C relay A/C request signal •BCM (CAN)
•ECM (CAN)
A/C compressor
HAC-20
Starter relay Ignition switch START signal TCM Starter motorSTR-8
Cooling fan relay Cooling fan request signal ECM (CAN) Cooling fan relayEC-36
Heated mirror relay Heate d mirror request signal BCM (CAN) Door mirrors DEF-4
ECM relayECM relay control signal ECM (CAN) ECM relayEC-21
Throttle control motor relay Throttle control motor control
signal ECM (CAN)
Throttle contro
l motor re-
lay EC-28
Fuel pump relay
Fuel pump request signal ECM (CAN) Fuel pumpEC-28
Ignition relay Ignition switch ON signal Ignition switch Ignition relayEC-31
Revision: March 2010 2008 QX56

PG-48
< COMPONENT DIAGNOSIS >
HARNESS
ENGINE CONTROL HARNESS
ALMIA0227GB
D5 F3 B/1 : A/C CompressorF2 F56 B/8 : Transfer terminal cord assembly
D5 F4 GR/1 : Oil pressure switch G1 F57 B/2 : Transfer motor
D2 F5 GR/4 : Air fuel ratio (A/F) sensor 1 (bank2) F2 F58 GR/6 : Transfer control device (actuator, position
switch)
C4 F6 GR/3 : Ignition coil No. 2 (with power
transistor) F2 F59 B/2 : Wait detection switch
Revision: March 2010
2008 QX56

PG
HARNESSPG-49
< COMPONENT DIAGNOSIS >
C
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C3 F7 GR/3
: Ignition coil No. 4 (with power
transistor) F1 F60 GR/2 : Neutral-4LO switch
C3 F8 GR/3 : Ignition coil No. 6 (with power
transistor)
D5 F61 G/2: Intake valve timing control solenoid valve
(bank 1)
E2 F9 G/10 : A/T assembly D5 F62 G/2: Intake valve timing control position sensor
(bank 1)
C3 F10 — : Engine ground C4 F63 G/2: Intake valve timing control solenoid valve
(bank 2)
D3 F11 B/3 : Crankshaft position sensor (POS) C4 F64 G/2 : Intake valve timing control position sensor
(bank 2)
E1 F12 G/4 : Heated oxygen sensor 2 (bank2) E3 F65 GR/4 : Air fuel ratio (A/F) sensor 1 (bank1)
F2 F13 G/4 : Heated oxygen sensor 2 (bank1) C2 F68 B/2 : Water valve
B2 F14 W/24 : To E5 C3 F101 B/6 : To F26
D4 F15 L/2 : EVAP canister purge volume control
solenoid valve C3 F102 B/2 : Knock sensor (bank 1)
E5 F16 — : Engine ground C3 F103 GR/2 : Engine coolant temperature sensor
C4 F18 GR/2 : Fuel injector No. 2 C3 F104 B/2 : Knock sensor (bank 2)
D4 F20 GR/2 : Fuel injector No. 4
F4 F21 W/2 : Condenser-1
D3 F22 GR/2 : Fuel injector No. 6
D4 F23 B/3 : Camshaft position sensor (phase)
D4 F26 B/6 : To F101
E3 F27 B/1 : Starter motor
D4 F30 GR/2 : Fuel injector No. 1
D3 F31 GR/2 : Fuel injector No. 8
B2 F32 W/16 : To E2
C2 F33 W/16 : To E19
C2 F34 W/2 : To E39
B3 F39 — : Fusible link (battery)
D4 F41 GR/2 : Fuel injector No. 3
D4 F42 GR/2 : Fuel injector No. 5
D3 F45 GR/2 : Fuel injector No. 7
B4 F46 B/3 : Power steering pressure sensor
E4 F47 GR/3 : Ignition coil No. 1 (with power
transistor)
E4 F48 GR/3 : Ignition coil No. 3 (with power
transistor)
E4 F49 GR/3 : Ignition coil No. 5 (with power
transistor)
D4 F50 B/6 : Electric throttle control actuator
E4 F51 GR/3 : Ignition coil No. 7 (with power
transistor)
D2 F52 GR/3 : Ignition coil No. 8 (with power
transistor)
E5 F53 B/6 : Mass air flow sensor
B2 F54 B/81 : ECM
F1 F55 B/2 : ATP switch
Revision: March 2010 2008 QX56

PG-50
< COMPONENT DIAGNOSIS >
HARNESS
CHASSIS HARNESS
AWMIA0113GB
G2 C1 SMJ : To E41
B5 C2 B/7 : Trailer
A3 C3 GR/8 : To C101
C3 C4 GR/3: Evap control system pressure
sensor
D2 C5 GR/5 : Fuel level sensor unit and fuel pump
Revision: March 2010 2008 QX56

PRECAUTIONSSCS-39
< PRECAUTION >
C
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SCS
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004900823
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Un it or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or el ectric power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers, always switch the Ignition OFF, disconnect the battery, and wait at least 3 minutes before performing any service.
Precaution for Rear SuspensionINFOID:0000000001732010
• When installing the rubber bushings, the final tightening must be done under unladen condition and with thetires on level ground. Oil will shorten the life of the rubber bushings, so wipe off any spilled oil immediately.
• Unladen condition means the fuel tank, engine coolant and lubricants are at the full specification. The spare tire, jack, hand tools, and mats are in their designated positions.
• After installing suspension components, check the wheel alignment.
• Caulking nuts are not reusable. Always use new caulking nuts for installation. New caulking nuts are pre-
oiled, do not apply any additional lubrication.
Revision: March 2010 2008 QX56

TM-30
< FUNCTION DIAGNOSIS >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ON BOARD DIAGNOSTIC (OBD) SYSTEM
IntroductionINFOID:0000000001604002
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic syst em (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MI L (malfunction indicator lamp) and is stored as a DTC in
the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the A/T CHECK indicator lamp. The malfunction is
stored in the TCM memory. The detected items are ov erlapped with OBD-II self-diagnostic items. For detail,
refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
OBD-II Function for A/T SystemINFOID:0000000001604003
The ECM provides emission-related on board diagnostic (O BD-II) functions for the A/T system. One function
is to receive a signal from the TCM used with OBD-relat ed parts of the A/T system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-re lated part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indi cator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to A/T system parts.
One or Two Trip Detection Logic of OBD-IIINFOID:0000000001604004
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — 1st Trip
If the same malfunction as that experienced during the fi rst test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd Trip
The “Trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)INFOID:0000000001604005
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( with CONSULT-III or GST) CONSULT-III or GST (Generic Scan Tool) Examples: P0705, P0720 etc.
These DTC are prescribed by SAE J2012.
(CONSULT-III also displays the malfunctioning component or system.)
• 1st trip DTC No. is the same as DTC No.
• Output of the diagnostic troubl e code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring or
occurred in the past and returned to normal.
CONSULT-III can identify them as shown below, therefore, CONSULT-III (if available) is recom-
mended.
Freeze Frame Data and 1st Trip Freeze Frame Data
The ECM has a memory function, which stores the driv ing condition such as fuel system status, calculated
load value, engine coolant temperatur e, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-III
or GST. The 1st trip freeze frame data can only be disp layed on the CONSULT-III screen, not on the GST. For
detail, refer to TM-30
.
Only one set of freeze frame data (either 1st trip freeze frame data of freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
Revision: March 2010 2008 QX56