2011 INFINITI QX56 fuel injector

EC-38
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
Homogeneous combustion is a combustion method that fuel
is injected during intake process so that combus-
tion occurs in the entire combustion chamber , as is common with conventional methods.
As for a start except for starts with the engine cold, homogeneous combustion occurs.
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 better reduce CO , HC and NOx emissions. This system uses A/F sen-
sor 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 A/F sensor 1, refer to
EC-21, "
Air Fuel Ratio (A/F) Sensor 1". 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 A/F sensor 1 shift, the 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 t he mixture ratio signal transmitted from A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM c ontrols 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 ai r flow sensor hot wire) and characteristic changes dur-
ing operation (i.e., fuel 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 carri ed out over time to compensate for continual deviation
of the “short-term fuel trim” from the central value. Continual deviation will occur due to individual engine differ-
ences, wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Sequential Direct Injection Gasoline System
PBIB2793E
Revision: 2010 May2011 QX56

EC-70
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
*: The item is indicated, but not used.
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
ECM TEMP 1
°C or °F  Displays a temperature calculated from a signal of
ECM temperature sensor 1.
ECM TEMP 2 °C or °F  Displays a temperature calculated from a signal of
ECM temperature sensor 2.
FUEL PUMP DUTY %  The control condition of the fuel pump control mod-
ule (FPCM) (determined by ECM according to the
input signals) is indicated.
Monitored item Unit Description Remarks
TEST ITEM CONDITION JUDGMENT CHECK ITEM (REMEDY)
VENT CON-
TROL/V  Ignition switch: ON (Engine
stopped)
 Turn solenoid valve ON and OFF with the CONSULT-III and listen
to operating sound. Solenoid valve makes an operating
sound.
 Harness and connectors
 Solenoid valve
ENG COOLANT
TEMP  Engine: Return to the original
non-standard condition
 Change the engine coolant tem- perature using CONSULT-III. If malfunctioning symptom disap-
pears, see CHECK ITEM.  Harness and connectors
 Engine coolant temperature sen-
sor
 Fuel injector
FUEL INJEC-
TION  Engine: Return to the original
non-standard condition
 Change the amount of fuel injec- tion using CONSULT-III. If malfunctioning symptom disap-
pears, see CHECK ITEM.
 Harness and connectors
 Fuel injector
 Air fuel ratio (A/F) sensor 1
FUEL/T TEMP
SEN  Change the fuel tank temperature using CONSULT-III.
PURG VOL
CONT/V  Engine: After warming up, run en-
gine at 1,500 rpm.
 Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-III. Engine speed changes according to
the opening percent.
 Harness and connectors
 Solenoid valve
FAN DUTY CON-
TROL* Ignition switch: ON
 Change duty ratio using CON-
SULT-III. Cooling fan speed changes.  Harness and connectors
 Cooling fan motor
 Cooling fan relay
 Cooling fan control module
 IPDM E/R
ALTERNATOR
DUTY Engine: Idle
 Change duty ratio using CON-
SULT-III. Battery voltage changes.  Harness and connectors
 IPDM E/R
Alternator
POWER BAL-
ANCE  Engine: After warming up, idle the
engine.
 A/C switch OFF
 Selector lever: P or N
 Cut off each injector signal one at a time using CONSULT-III. Engine runs rough or stops.
 Harness and connectors
 Compression
 Fuel injector
 Power transistor
Spark plug
 Ignition coil
IGNITION TIM-
ING  Engine: Return to the original
non-standard condition
 Timing light: Set
 Retard the ignition timing using
CONSULT-III. If malfunctioning symptom disap-
pears, see CHECK ITEM.
 Perform Idle Air Volume Learning.
Revision: 2010 May2011 QX56

EC-78
< ECU DIAGNOSIS INFORMATION >[VK56VD]
ECM
Te r m i n a l N o .
(Wire color) Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
Output
1
(R)
2
(R) 175
(B) Fuel injector No. 8 (HI)
Fuel injector No. 5 (HI)
Output[Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
3
(G)
4
(G) 175
(B) Fuel injector No. 3 (LO)
Fuel injector No. 2 (LO)
Input[Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
5
(B/R) — ECM ground — — —
JPBIA3345ZZ
JPBIA3347ZZ
JPBIA3355ZZ
JPBIA3356ZZ
Revision: 2010 May2011 QX56

ECM
EC-79
< ECU DIAGNOSIS INFORMATION > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
6
(R) 7
(R) 175
(B) Fuel injector No. 3 (HI)
Fuel injector No. 2 (HI)
Output[Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
8
(G) 9
(G) 175
(B) Fuel injector No. 8 (LO)
Fuel injector No. 5 (LO)
Input[Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
10
(B) — ECM ground — — —
11
(BR) 175
(B) PNP switch Input [Ignition switch: ON]
 Selector lever: P or N position
BATTERY VOLTAGE
(11 - 14 V)
[Ignition switch: ON]
 Selector lever: Except above posi- tion 0 V
Te r m i n a l N o .
(Wire color) Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
OutputJPBIA3345ZZ
JPBIA3347ZZ
JPBIA3355ZZ
JPBIA3356ZZ
Revision: 2010 May2011 QX56

EC-82
< ECU DIAGNOSIS INFORMATION >[VK56VD]
ECM
37
(V) 175
(B) Cooling fan speed Input [Ignition switch: ON]
 Engine stopped
5 V
[Engine is running]
 Idle speed
 After warm-up condition BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Idle speed
 Before warm-up condition BATTERY VOLTAGE
(11 - 14 V)
39
(P/B) 45
(L/O) Power steering pressure sensor Input [Engine is running]
 Steering wheel: Being turned
0.5 - 4.5 V
[Engine is running]
 Steering wheel: Not being turned 0.4 - 0.8 V
40
(W/L) —Sensor ground
(Fuel rail pressure sensor/En-
gine coolant temperature sen-
sor/Engine oil temperature
sensor) —— —
42
(L/Y) 40
(W/L) Engine oil temperature sensor Input [Engine is running] 0 - 4.8 V
Output voltage varies with engine
oil temperature.
45
(L/O) —Sensor ground
(Power steering pressure sen-
sor/ Low fuel pressure sensor/
Electrically-controlled cooling
fan coupling) —— —
46
(SB) 175
(B) Fuel injector driver power supply Input [Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14 V)
[Ignition switch: OFF] 1.5 V
47
(G) 175
(B) Heated oxygen sensor 2 heater
(bank 1)
Input[Engine is running]
 Engine speed: Below 3,600 rpm af-
ter the following conditions are met
- Engine: after warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute
and at idle for 1 minute under no
load 10 V
[Ignition switch: ON]
 Engine: Stopped
[Engine is running]
 Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14 V)
Te r m i n a l N o .
(Wire color) Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
Output
JPBIA3332ZZ
JPBIA3733ZZ
JMBIA0037GB
Revision: 2010 May2011 QX56

ECM
EC-83
< ECU DIAGNOSIS INFORMATION > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
48
(L/W) 175
(B) A/F sensor 1 heater (bank 1) Input [Engine is running]
 Warm-up condition
 Idle speed
(More than 140 seconds after start-
ing engine) 2.9 - 8.8 V
49
(LG/
B) 175
(B) Intake valve timing control sole-
noid valve (bank 1)
Output[Engine is running]
 Warm-up condition
 Idle speed
BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000rpm 7 - 12 V
51
(R) 175
(B) Fuel injector driver power supply Output [Engine is running]
 Warm-up condition
 Idle speed
BATTERY VOLTAGE
(11 - 14 V)
[Ignition switch: OFF] 1.5 V
52
(L/R) 175
(B) Heated oxygen sensor 2 heater
(bank 2)
Output[Engine is running]
 Engine speed: Below 3,600 rpm af-
ter the following conditions are met
- Engine: after warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute
and at idle for 1 minute under no
load 10 V
[Ignition switch: ON]
 Engine: Stopped
[Engine is running]
 Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14 V)
53
(SB) 175
(B) A/F sensor 1 heater (bank 2) Output [Engine is running]
 Warm-up condition
 Idle speed
(More than 140 seconds after start-
ing engine) 2.9 - 8.8 V
Te r m i n a l N o .
(Wire color) Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
Output
JPBIA3361ZZ
JMBIA0038GB
JMBIA0037GB
JPBIA3361ZZ
Revision: 2010 May2011 QX56

EC-88
< ECU DIAGNOSIS INFORMATION >[VK56VD]
ECM
101
(R)
102 (R) 175
(B) Fuel injector No. 1 (HI)
Fuel injector No. 6 (HI)
Input[Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
103 (G)
104 (G) 175
(B) Fuel injector No. 7 (LO)
Fuel injector No. 4 (LO)
Output[Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
105
(L/W) 175
(B) High pressure fuel pump (HI) Input [Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
Te r m i n a l N o .
(Wire color) Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
OutputJPBIA3345ZZ
JPBIA3347ZZ
JPBIA3355ZZ
JPBIA3356ZZ
JPBIA3340ZZ
JPBIA3341ZZ
Revision: 2010 May2011 QX56

ECM
EC-89
< ECU DIAGNOSIS INFORMATION > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
106
(R)
107 (R) 175
(B) Fuel injector No. 7 (HI)
Fuel injector No. 4 (HI)
Output[Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
108 (G)
109 (G) 175
(B) Fuel injector No. 1 (LO)
Fuel injector No. 6 (LO)
Output[Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
11 0
(L/B) 175
(B) High pressure fuel pump (LO) Input [Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
Te r m i n a l N o .
(Wire color) Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
OutputJPBIA3345ZZ
JPBIA3347ZZ
JPBIA3355ZZ
JPBIA3356ZZ
JPBIA3342ZZ
JPBIA3343ZZ
Revision: 2010 May2011 QX56