2008 INFINITI QX56 fuel pump

MWI
FUEL LEVEL SENSOR SIGNAL CIRCUITMWI-33
< COMPONENT DIAGNOSIS >
C
DE
F
G H
I
J
K L
M B A
O P
FUEL LEVEL SENSOR SIGNAL CIRCUIT
DescriptionINFOID:0000000001691293
The fuel level sensor unit and fuel pump detects the approx imate fuel level in the fuel tank and transmits the
fuel level signal to the combination meter.
Component Function CheckINFOID:0000000001691294
1.COMBINATION METER INPUT SIGNAL
1. Select “METER/M&A” on CONSULT-III.
2. Using “FUEL METER” of “DATA MONITOR”, comp are the value of DATA MONITOR with fuel gauge
pointer of combination meter.
Does the data monitor value approximately match the fuel gauge indication?
YES >> Inspection End.
NO >> Replace combination meter. Refer to MWI-76, "
Removal and Installation".
Diagnosis ProcedureINFOID:0000000001691295
1.CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Check combination meter and fuel level sensor unit terminals (meter-side and harness-side) for poor con- nection.
Is the inspection result normal?
YES >> GO TO 2
NO >> Repair or replace terminals or connectors.
2.CHECK FUEL LEVEL SENSOR UNIT CIRCUIT
1. Disconnect combination meter connector and fuel level sensor unit connector.
2. Check continuity between combination meter harness connector
(B) and fuel level sensor unit and fuel pump harness connector
(A).
3. Check continuity between fuel level sensor unit and fuel pump harness connector (A) and ground.
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair harness or connector.
Fuel gauge pointer Reference value of data monitor [lit.]
Full Approx. 93
3/4 Approx. 73
1/2 Approx. 52
1/4 Approx. 30
Empty Approx. 11
AB
Continuity
Connector Terminal Connector Terminal
C5 2 M24 3 Yes
A GroundContinuity
Connector Terminal
C5 2 No
AWNIA0206ZZ
Revision: March 2010 2008 QX56

MWI-34
< COMPONENT DIAGNOSIS >
FUEL LEVEL SENSOR SIGNAL CIRCUIT
3.CHECK FUEL LEVEL SENSOR UNIT GROUND CIRCUIT
1. Check continuity between combination meter harness connector (B) and fuel level sensor uni t and fuel pump harness connector
(A).
2. Check continuity between fuel level sensor unit and fuel pump harness connector (A) and ground.
Is the inspection result normal?
YES >> GO TO 4
NO >> Repair harness or connector.
4.CHECK INSTALLATION CONDITION
Check fuel level sensor unit installation, and check whether the float arm interferes or binds with any of the
internal components in the fuel tank.
Is the inspection result normal?
YES >> Inspection End.
NO >> Install the fuel level sensor unit properly.
Component InspectionINFOID:0000000001691296
1.REMOVE FUEL LEVEL SENSOR UNIT
Remove the fuel level sensor unit. Refer to FL-7, "
Removal and Installation".
>> GO TO 2
2.CHECK FUEL LEVEL SENSOR UNIT AND FUEL PUMP
Check the resistance between terminals 2 and 5.
*1 and *2: When float arm is in contact with stopper.
Is inspection result normal?
YES >> Inspection End.
NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-7, "
Removal and Installation".
AB Continuity
Connector Terminal Connector Terminal
C5 5 M24 4 Yes
A GroundContinuity
Connector Terminal
C5 5 No
AWNIA0207ZZ
Te r m i n a l Float position
mm (in) Resistance value
(Approx.)
25 *1 Empty
7.5 (0.3)80Ω
*2 Full 218.9 (8.6)6Ω
LKIA0402E
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

PCS-22
< ECU DIAGNOSIS >[IPDM E/R]
IPDM E/R (INTELLIGENT POWER DI
STRIBUTION MODULE ENGINE ROOM)
Te r m i n a lWire
color Signal name Signal
input/
output Measuring condition
Reference value(Approx.)
Igni-
tion
switch Operation or condition
1 B/Y Battery power supply Input OFF —Battery voltage
2 R Battery power supply Input OFF —Battery voltage
3 BR ECM relay Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
4 W/L ECM relay Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
6L Throttle control motor
relay Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
7 W/B ECM relay control Input — Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
8 R/B Fuse 54 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
10 G Fuse 45 Output ONDaytime light system active
0V
Daytime light system inactive Battery voltage
11 Y/B A/C compressor Output ON or
START A/C switch ON or defrost A/C
switch
Battery voltage
A/C switch OFF or defrost A/C
switch 0V
12 L/W Ignition switch sup-
plied power Input —OFF or ACC
0V
ON or START Battery voltage
13 B/Y Fuel pump relay Output — Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
14 Y/R Fuse 49 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
15 LG/B Fuse 50 (VDC) Output — Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
15 GR Fuse 50 (ABS) Output — Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
16 G Fuse 51 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
17 W Fuse 55 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
19 W/R Starter motor Output START—Battery voltage
21 BR Ignition switch sup-
plied power
Input —OFF or ACC
0V
START Battery voltage
22 G Battery power supply Output OFF —Battery voltage
23 GR/W Door mirror defogger
output signal Output —When rear defogger switch is
ON
Battery voltage
When raker defogger switch is
OFF 0V
Revision: March 2010
2008 QX56

PCS-24
< ECU DIAGNOSIS >[IPDM E/R]
IPDM E/R (INTELLIGENT POWER DI
STRIBUTION MODULE ENGINE ROOM)
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 (trans-
mission range switch) Input
ON or
START A/T shift selector lever in "P"
or "N"
0V
A/T shift selector lever any
other position 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
Te r m i n a l
Wire
co lor Si
gn

al nameSignal
input/
output Measuring condition
Reference value(Approx.)
Igni-
tion
switch Operation or condition
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

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
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
1 B/Y Battery power supply Input OFF —Battery voltage
2 R Battery power supply Input OFF —Battery voltage
3BRECM relay Output— Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
4W/LECM relay Output— Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
6L Throttle control motor
relay Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
7 W/B ECM relay control Input — Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
8 R/B Fuse 54 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
10 G Fuse 45 Output ONDaytime light system active
0V
Daytime light system inactive Battery voltage
11 Y/B A/C compressor Output ON or
START A/C switch ON or defrost A/C
switch
Battery voltage
A/C switch OFF or defrost A/C
switch 0V
12 L/W Ignition switch sup-
plied power Input —OFF or ACC
0V
ON or START Battery voltage
13 B/Y Fuel pump relay Output — Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
14 Y/R Fuse 49 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
15 LG/B Fuse 50 (VDC) Output — Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
15 GR Fuse 50 (ABS) Output — Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
16 G Fuse 51 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
17 W Fuse 55 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
19 W/R Starter motor Output START—Battery voltage
21 BR Ignition switch sup-
plied power
Input —OFF or ACC
0V
START Battery voltage
22 G Battery power supply Output OFF —Battery voltage
23 GR/W Door mirror defogger
output signal Output —When rear defogger switch is
ON
Battery voltage
When raker defogger switch is
OFF 0V
Revision: March 2010
2008 QX56

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
SEC-103
< 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 (trans-
mission range switch) Input
ON or
START A/T shift selector lever in "P"
or "N"
0V
A/T shift selector lever any
other position 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
Te r m i n a l
Wire
col or Si
gn

al nameSignal
input/
output Measuring condition
Reference value(Approx.)
Igni-
tion
switch Operation or condition
Revision: March 2010
2008 QX56