Page 1697 of 4083
EC-398
< COMPONENT DIAGNOSIS >[VK56DE]
ELECTRICAL LOAD SIGNAL
>>
INSPECTION END
Revision: March 2010 2008 QX56
Page 1698 of 4083
![INFINITI QX56 2008 Factory Service Manual FUEL INJECTOREC-399
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
FUEL INJECTOR
Component DescriptionINFOID:0000000001365875
The fuel injector is a small, precise solenoid valve. Wh INFINITI QX56 2008 Factory Service Manual FUEL INJECTOREC-399
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
FUEL INJECTOR
Component DescriptionINFOID:0000000001365875
The fuel injector is a small, precise solenoid valve. Wh](/manual-img/42/57030/w960_57030-1697.png)
FUEL INJECTOREC-399
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
FUEL INJECTOR
Component DescriptionINFOID:0000000001365875
The fuel injector is a small, precise solenoid valve. When the ECM
supplies a ground to the fuel injector circuit, the coil in the fuel injec-
tor is energized. The energized coil pulls the ball valve back and
allows fuel to flow through the fuel injector into the intake manifold.
The amount of fuel injected depends upon the injection pulse dura-
tion. Pulse duration is the length of time the fuel injector remains
open. The ECM controls the injection pulse duration based on
engine fuel needs.
Diagnosis ProcedureINFOID:0000000001365878
1.INSPECTION START
Turn ignition switch to START.
Is any cylinder ignited?
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
2.CHECK OVERALL FUNCTION
With CONSULT-IIl
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-IIl.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-IIl
1. Start engine.
2. Listen to each fuel injector operating sound.
Clicking noise should be heard.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3.CHECK FUEL INJECTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
SEF375Z
PBIB1986E
Revision: March 2010 2008 QX56
Page 1699 of 4083
![INFINITI QX56 2008 Factory Service Manual EC-400
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL INJECTOR
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with
CONSUL INFINITI QX56 2008 Factory Service Manual EC-400
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL INJECTOR
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with
CONSUL](/manual-img/42/57030/w960_57030-1698.png)
EC-400
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL INJECTOR
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with
CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• IPDM E/R connector E119
• 15A fuse
• Harness for open or short between fuel injector and fuse
>> Repair harness or connectors.
5.CHECK FUEL INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between fuel injector terminal 2 and ECM terminals 21, 22, 23, 40, 41, 42, 44, 63.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK FUEL INJECTOR
Refer to EC-401, "
Component Inspection".
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning fuel injector.
7.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Voltage: Battery voltage
BBIA0374E
PBIB0582E
Continuity should exist.
Revision: March 2010
2008 QX56
Page 1700 of 4083
FUEL INJECTOREC-401
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Component InspectionINFOID:0000000001365879
FUEL INJECTOR
1. Disconnect fuel injector harness connector.
2. Check resistance between terminals as shown in the figure.
Resistance: 11.1 - 14.5 Ω [at 10 - 60 °C (50 - 140 °F)]
PBIB1727E
Revision: March 2010 2008 QX56
Page 1701 of 4083
![INFINITI QX56 2008 Factory Service Manual EC-402
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
FUEL PUMP
DescriptionINFOID:0000000001365881
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery vo INFINITI QX56 2008 Factory Service Manual EC-402
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
FUEL PUMP
DescriptionINFOID:0000000001365881
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery vo](/manual-img/42/57030/w960_57030-1700.png)
EC-402
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
FUEL PUMP
DescriptionINFOID:0000000001365881
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal
from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The EC M stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump
relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.
Diagnosis ProcedureINFOID:0000000001365884
1.CHECK OVERALL FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose with two fingers.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
Sensor Input signal to ECMECM FunctionActuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown above Stops.
BBIA0402E
Fuel pressure pulsation should be felt on the fuel feed
hose for 1 second after igniti on switch is turned ON.
BBIA0357E
Revision: March 2010 2008 QX56
Page 1702 of 4083
![INFINITI QX56 2008 Factory Service Manual FUEL PUMPEC-403
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
4. Check voltage between ECM terminal 113 and ground with
CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3. INFINITI QX56 2008 Factory Service Manual FUEL PUMPEC-403
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
4. Check voltage between ECM terminal 113 and ground with
CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.](/manual-img/42/57030/w960_57030-1701.png)
FUEL PUMPEC-403
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
4. Check voltage between ECM terminal 113 and ground with
CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
3.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II
Check voltage between IPDM E/R terminal 46 and ground with
CONSULT-IIl or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 13.
4.DETECT MALFUNCTIONING PART
Check harness for open or short between IPDM E/R and ECM.
>> Repair harness or connectors.
5.CHECK CONDENSER-2 POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Disconnect condenser-2 harness connector.
4. Turn ignition switch ON.
5. Check voltage between condenser-2 terminal 1 and ground with CONSULT-IIl or tester.
6. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6.CHECK 15A FUSE
1. Turn ignition switch OFF. Voltage: Battery voltage
PBIB1187E
Voltage: Battery voltage
PBIB2656E
BBIA0388E
Voltage: Battery voltage should exist for 1 sec-
ond after ignition switch is turned ON.
PBIB0624E
Revision: March 2010 2008 QX56
Page 1703 of 4083
![INFINITI QX56 2008 Factory Service Manual EC-404
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
2. Disconnect 15A fuse.
3. Check 15A fuse.
OK or NG
OK >> GO TO 7.
NG >> Replace fuse.
7.CHECK CONDENSER-2 POWER SUPPLY
CIRCUIT-II FOR OPEN AND SHORT
INFINITI QX56 2008 Factory Service Manual EC-404
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
2. Disconnect 15A fuse.
3. Check 15A fuse.
OK or NG
OK >> GO TO 7.
NG >> Replace fuse.
7.CHECK CONDENSER-2 POWER SUPPLY
CIRCUIT-II FOR OPEN AND SHORT](/manual-img/42/57030/w960_57030-1702.png)
EC-404
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
2. Disconnect 15A fuse.
3. Check 15A fuse.
OK or NG
OK >> GO TO 7.
NG >> Replace fuse.
7.CHECK CONDENSER-2 POWER SUPPLY
CIRCUIT-II FOR OPEN AND SHORT
1. Disconnect IPDM E/R harness connector E119.
2. Check harness continuity between IPDM E/R terminal 13 and condenser-2 terminal 1. Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK CONDENSER-2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between condenser-2
+ terminal 2 and ground.
Refer to Wiring Diagram.
2. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to power in harness or connectors.
9.CHECK CONDENSER-2
Refer to EC-405, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> Replace condenser-2.
10.CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor unit and fuel pump” harness con- nector.
3. Disconnect IPDM E/R harness connector E119.
4. Check harness continuity between IPDM E/R terminal 13 and “fuel level sensor unit and fuel pump” terminal 1, “fuel level sen-
sor unit and fuel pump” terminal 3 and ground.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E41, C1
• Harness for open or short between fuel pump and IPDM E/R
• Harness for open or short between fuel pump and ground Continuity should exist.
Continuity should exist.
Continuity should exist.
BBIA0583E
Revision: March 2010
2008 QX56
Page 1704 of 4083
FUEL PUMPEC-405
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
>> Repair open circuit or short to ground or short to power in harness or connectors.
12.CHECK FUEL PUMP
Refer to EC-405, "
Component Inspection".
OK or NG
OK >> GO TO 13.
NG >> Replace “fuel level sensor unit and fuel pump”.
13.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair or replace harness or connectors.
Component InspectionINFOID:0000000001365885
FUEL PUMP
1. Disconnect “fuel level sensor unit and fuel pump” harness connector.
2. Check resistance between fuel level sensor unit and fuel pump terminals 1 and 3.
CONDENSER-2
1. Turn ignition switch OFF.
2. Disconnect condenser-2 harness connector.
3. Check resistance between condenser-2 terminals as 1 and 2. Resistance: 0.2 - 5.0
Ω [at 25 °C (77 °F)]
SEC918C
Resistance Above 1 MΩ at 25 °C (77 °F)
PBIB0794E
Revision: March 2010 2008 QX56