2010 INFINITI QX56 engine

ECM
EC-471
< ECU DIAGNOSIS > [VK56DE]
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HO2S 05H
Air fuel ratio (A/F) sensor 1
(Bank 2) P0151 83H 0BH
Minimum sensor output voltage for test
cycle
P0151 84H 0BH Maximum sensor output voltage for test
cycle
P0150 85H 0BH Minimum sensor output voltage for test
cycle
P0150 86H 0BH Maximum sensor output voltage for test
cycle
P0153 87H 04H Response rate: Response ratio (Lean to
Rich)
P0153 88H 04H Response rate: Response ratio (Rich to
Lean)
P2A03 89H 84H The amount of shift in air fuel ratio
P2A03 8AH 84H The amount of shift in air fuel ratio P0150 8BH 0BH Difference in sensor output voltage
P0153 8CH 83H Response gain at the limited frequency
06H Heated oxygen sensor 2
(Bank 2) P0158 07H 0CH
Minimum sensor output voltage for test
cycle
P0157 08H 0CH Maximum sensor output voltage for test
cycle
P0158 80H 0CH Sensor output voltage
P0159 81H 0CH Difference in sensor output voltage
07H Heated oxygen sensor 3
(Bank2) P0163 07H 0CH
Minimum sensor output voltage for test
cycle
P0164 08H 0CH Maximum sensor output voltage for test
cycle
P0166 80H 0CH Sensor output voltage
P0165 81H 0CH Difference in sensor output voltage
CATA-
LY S T 21H
Three way catalyst function
(Bank1) P0420 80H 01H O2 storage index
P0420 82H 01H
Switching time lag engine exhaust index
value
P2423 83H 0CH Difference in 3rd O2 sensor output volt-
age
P2423 84H 84H O2 storage index in HC trap catalyst
22H Three way catalyst function
(Bank2) P0430 80H 01H O2 storage index
P0430 82H 01H
Switching time lag engine exhaust index
value
P2424 83H 0CH Difference in 3rd O2 sensor output volt-
age
P2424 84H 84H O2 storage index in HC trap catalyst
Item
OBD-
MID Self-diagnostic test item
DTCTest value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: April 20092010 QX56

EC-476
< ECU DIAGNOSIS >[VK56DE]
ECM
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Perform TM-30, "
OBD-II Diagnostic Trouble Code (DTC)". (The DTC in TCM will be erased)
3. Select Service $04 with GST (Generic Scan Tool).
No Tools
NOTE:
If the DTC is not for AT related items (see EC-459, "
DTC Index"), skip step 2.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once.
Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Perform TM-30, "
OBD-II Diagnostic Trouble Code (DTC)". (The DTC in the TCM will be erased.)
3. Change the diagnostic test mode from Mode II to Mode I by depressing the accelerator pedal. Refer to
EC-55, "
Malfunction Indicator Lamp (MIL)".
• If the battery is disconnected, the emission-related diagnostic information will be lost within 24
hours.
• The following data are cleared when the ECM memory is erased.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
Revision: April 20092010 QX56

ENGINE CONTROL SYSTEM SYMPTOMSEC-477
< SYMPTOM DIAGNOSIS > [VK56DE]
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SYMPTOM DIAGNOSIS
ENGINE CONTROL SYSTEM SYMPTOMS
Symptom Matrix ChartINFOID:0000000005149500
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 11232 22 3 2EC-399
Fuel pressure regulator system 334444444 4 EC-489
Injector circuit11232 22 2EC-396
Evaporative emission system 334444444 4 EC-37
Air Positive crankcase ventilation sys-
tem 334444444 41
EC-417
Incorrect idle speed adjustment 1 1 1 1 1EC-13
Electric throttle control actuator 112332222 2 2 EC-356
,
EC-359
,
EC-363
,
EC-365
IgnitionIncorrect ignition timing adjustment 33111 11 1EC-13
Ignition circuit 11222 22 2EC-407
Main power supply and ground circuit 22333 33 23 EC-82
Revision: April 20092010 QX56

EC-478
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Mass air flow sensor circuit
1
12 2
222 2 EC-104,
EC-110
Engine coolant temperature sensor circuit
333
EC-121,
EC-129
Air fuel ratio (A/F ) sensor 1 circuit EC-137
,
EC-141
,
EC-145
,
EC-149
,
EC-382

Throttle position sensor circuit 22EC-125
,
EC-188
,
EC-306
,
EC-308
,
EC-374
Accelerator pedal position sensor circuit 3 2 1EC-284
,
EC-367
,
EC-370
,
EC-378
Knock sensor circuit 23EC-198
Crankshaft position sensor (POS) circuit 2 2 EC-201
Camshaft position sensor (PHASE) circuit 3 2 EC-205
Vehicle speed signal circuit2 3 33EC-275
Power steering pressu re sensor circuit 23 3 EC-281
ECM 22333333333 EC-284,
EC-286
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-101
Park/Neutral position (PNP) signal circuit3 3 3 33EC-292
Refrigerant pressure sensor circuit 233 4 EC-419
Electrical load signal circuit 3EC-394
Air conditioner circuit 223333333 3 2 HAC-25
ABS actuator and electric unit (control unit) 4 BRC-36
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: April 20092010 QX56

ENGINE CONTROL SYSTEM SYMPTOMSEC-479
< SYMPTOM DIAGNOSIS > [VK56DE]
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SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank 5
5 FL-11
Fuel piping
5 5 5 5 55FL-6
Va p o r l o c k —
Valve deposit 5 555 55 5—
Poor fuel (Heavy weight gasoline,
Low octane) —
Air Air duct
55555 5 EM-25
Air cleaner
EM-25
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555 EM-25
Electric throttle control actuator
EM-26
Air leakage from intake manifold/
Collector/GasketEM-26
Cranking Battery
111111
11
PG-74
Generator circuit
CHG-6
Starter circuit3 STR-8
Signal plate6 EM-45
Park/Neutral position (PNP) sig-
nal4
TM-45
Engine Cylinder head
55555 55 5 EM-68
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-83
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nism Timing chain
55555 55 5EM-45
Camshaft
EM-53
Intake valve timing controlEM-53
Intake valve
3EM-68
Exhaust valve
Revision: April 20092010 QX56

EC-480
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket 55555 55 5EM-30
,
EX-
5Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-33
,
LU-
14 , LU-11 ,
LU-12
Oil level (Low)/Filthy oil LU-8, "In-
spection"
Cooling Radiator/Hose/Radiator filler cap
55555 55 45 CO-15
Thermostat
5CO-22
Water pump CO-20
Water galleryCO-6
Cooling fan5CO-18,
CO-
19
Coolant level (Low)/Contaminat-
ed coolant 5
CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS) 11
SEC-9
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: April 20092010 QX56

NORMAL OPERATING CONDITIONEC-481
< SYMPTOM DIAGNOSIS > [VK56DE]
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NORMAL OPERATING CONDITION
Fuel Cut Control (at No
Load and High Engine Speed)INFOID:0000000005149501
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed over is 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under EC-28, "
System Description".
Sensor Input signal to ECMECM functionActuator
TCM Neutral position
Fuel cut control Fuel injector
Accelerator pedal position sensor
Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed
Wheel sensor Vehicle speed*
Revision: April 20092010 QX56

EC-482
< PRECAUTION >[VK56DE]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint Syst
em (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005149502
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity 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 SRS and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, 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 unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified by yellow and/or orange harnesses or har-
ness connectors.
On Board Diagnosis (OBD) S ystem of Engine and A/TINFOID:0000000005149503
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
• Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any repair
or inspection work. The open/short circuit of re lated switches, sensors, solenoid valves, etc. will
cause the MIL to light up.
• Be sure to connect and lock the connectors secure ly after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
• Certain systems and components, especially those related to OBD, may use a new style slide-lock-
ing type harness connector. For descrip tion and how to disconnect, refer to PG-64
.
• Be sure to route and secure the harnesses properly after work. The interference of the harness with
a bracket, etc. may cause the MIL to li ght up due to the short circuit.
• Be sure to connect rubber tubes properly afte r work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.
• Be sure to erase the unnecessary malfunction info rmation (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionINFOID:0000000005149504
•Always use a 12 volt battery as power source.
• Do not attempt to disconnect battery cables while engine is
running.
• Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative bat-
tery cable. Failure to do so may damage the ECM because
battery voltage is applied to ECM even if ignition switch is
turned OFF.
• Before removing parts, turn ig nition switch OFF and then dis-
connect negative battery cable.
SEF289H
Revision: April 20092010 QX56