battery INFINITI QX4 2005 Factory Service Manual

EC-16Revision: October 2005
PRECAUTIONS
2005 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
UBS00KZ0
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 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 whether 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.
WAR NIN G:

To avoid rendering the SRS inoperative, 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 per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
On Board Diagnostic (OBD) System of Engine and A/TUBS00KZ1
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 related switches, sensors, solenoid valves,
etc. will cause the MIL to light up.

Be sure to connect and lock the connectors securely 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-
locking type harness connector. For description and how to disconnect, refer to PG-67, "
HAR-
NESS CONNECTOR" .

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 light up due to the short circuit.

Be sure to connect rubber tubes properly after 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 information (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionUBS00KZ2

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
battery 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 ignition switch OFF and then
disconnect battery ground cable.
SEF 2 89 H

PRECAUTIONS
EC-17
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Revision: October 20052005 QX56

Do not disassemble ECM.

If a battery cable is disconnected, the memory will return to
the ECM value.
The ECM will now start to self-control at its initial value.
Engine operation can vary slightly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.

If the battery is disconnected, the following emission-
related diagnostic information will be lost within 24 hours.
–Diagnostic trouble codes
–1st trip diagnostic trouble codes
–Freeze frame data
–1st trip freeze frame data
–System readiness test (SRT) codes
–Test values

When connecting ECM harness connector, fasten it
securely with a lever as far as it will go as shown in the fig-
ure.

When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.

Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.

Keep engine control system harness at least 10 cm (4 in)
away from adjacent harness, to prevent engine control sys-
tem malfunctions due to receiving external noise, degraded
operation of ICs, etc.

Keep engine control system parts and harness dry.

Before replacing ECM, perform ECM Terminals and Refer-
ence Value inspection and make sure ECM functions prop-
erly. Refer to EC-117, "
ECM Terminals and Reference Value"
.

Handle mass air flow sensor carefully to avoid damage.

Do not disassemble mass air flow sensor.

Do not clean mass air flow sensor with any type of deter-
gent.

Do not disassemble electric throttle control actuator.

Even a slight leak in the air intake system can cause seri-
ous incidents.

Do not shock or jar the camshaft position sensor (PHASE), crankshaft position sensor (POS).
PBIB11 64 E
BBIA0387E
PBIB0090E
MEF040D

EC-24Revision: October 2005
ENGINE CONTROL SYSTEM
2005 QX56
Multiport Fuel Injection (MFI) SystemUBS00KZ7
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.
<Fuel increase>

During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation
<Fuel decrease>

During deceleration

During high engine speed operation
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)*
2VDC/TCS operation command
Air conditioner switch*
2Air conditioner operation
Wheel sensor*
2Vehicle speed

EC-26Revision: October 2005
ENGINE CONTROL SYSTEM
2005 QX56
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all eight cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The eight injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speed.
Electronic Ignition (EI) SystemUBS00KZ8
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Firing order: 1 - 8 - 7 - 3 - 6 - 5 - 4 -2
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Comput-
ing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revised by the ECM according to the other data stored in
the ECM.

At starting

During warm-up

At idle

At low battery voltage
PBIB0122E
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2
Piston position
Ignition timing
controlPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor*1Vehicle speed

EC-28Revision: October 2005
AIR CONDITIONING CUT CONTROL
2005 QX56
AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartUBS00KZA
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
System DescriptionUBS00KZB
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.

When the accelerator pedal is fully depressed.

When cranking the engine.

At high engine speeds.

When the engine coolant temperature becomes excessively high.

When operating power steering during low engine speed or low vehicle speed.

When engine speed is excessively low.

When refrigerant pressure is excessively low or high.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch*
1Air conditioner ON signal
Air conditioner
cut controlAir conditioner relay Accelerator pedal position sensor Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed

EC-38Revision: October 2005
EVAPORATIVE EMISSION SYSTEM
2005 QX56
WITHOUT CONSULT-II
1. Attach the EVAP service port adapter securely to the EVAP ser-
vice port.
2. Also attach the pressure pump with pressure gauge to the EVAP
service port adapter.
3. Apply battery voltage between the terminals of EVAP canister vent control valve to make a closed EVAP
system.
4. To locate the leak, deliver positive pressure to the EVAP system until pressure gauge points reach 1.38 to
2.76 kPa (0.014 to 0.028 kg/cm
2 , 0.2 to 0.4 psi).
5. Remove EVAP service port adapter and hose with pressure pump.
6. Locate the leak using a leak detector. Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
BBIA0366E
SEF 4 62 UA
BBIA0443E

ON BOARD REFUELING VAPOR RECOVERY (ORVR)
EC-39
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ON BOARD REFUELING VAPOR RECOVERY (ORVR)PFP:00032
System DescriptionUBS00KZJ
From the beginning of refueling, the air and vapor inside the fuel tank go through refueling EVAP vapor cut
valve and EVAP/ORVR line to the EVAP canister. The vapor is absorbed by the EVAP canister and the air is
released to the atmosphere.
When the refueling has reached the full level of the fuel tank, the refueling EVAP vapor cut valve is closed and
refueling is stopped because of auto shut-off. The vapor which was absorbed by the EVAP canister is purged
during driving.
WA RN ING:
When conducting inspections below, be sure to observe the following:

Put a “CAUTION: INFLAMMABLE” sign in workshop.

Do not smoke while servicing fuel system. Keep open flames and sparks away from work area.

Be sure to furnish the workshop with a CO2 fire extinguisher.
CAUTION:

Before removing fuel line parts, carry out the following procedures:
–Put drained fuel in an explosion-proof container and put lid on securely.
–Release fuel pressure from fuel line. Refer to EC-93, "FUEL PRESSURE RELEASE" .
–Disconnect battery ground cable.

Always replace O-ring when the fuel gauge retainer is removed.

Do not kink or twist hose and tube when they are installed.

Do not tighten hose and clamps excessively to avoid damaging hoses.

After installation, run engine and check for fuel leaks at connection.

Do not attempt to top off the fuel tank after the fuel pump nozzle shuts off automatically.
Continued refueling may cause fuel overflow, resulting in fuel spray and possibly a fire.
PBIB1068E

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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WITH GST
The emission related diagnostic information in the ECM can be erased by selecting Service $04 with GST.
NOTE:
If the DTC is not for A/T related items (see EC-8, "
INDEX FOR DTC" ), 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 AT-37, "
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-8, "
INDEX FOR DTC" ), 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 AT-37, "
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-65, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .

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
SCIA5671E

EC-66Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
The DTC and 1st trip DTC are displayed at the same time. If the MIL does not illuminate in diagnostic test
mode I (Malfunction warning), all displayed items are 1st trip DTCs. If only one code is displayed when the MIL
illuminates in diagnostic test mode II (SELF-DIAGNOSTIC RESULTS), it is a DTC; if two or more codes are
displayed, they may be either DTCs or 1st trip DTCs. DTC No. is same as that of 1st trip DTC. These uniden-
tified codes can be identified by using the CONSULT-II or GST. A DTC will be used as an example for how to
read a code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle.
The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-8, "
INDEX FOR DTC" )
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to EC-
65, "How to Erase Diagnostic Test Mode II (Self-diagnostic Results)" .

If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.

Be careful not to erase the stored memory before starting trouble diagnoses.
OBD System Operation ChartUBS00KZT
RELATIONSHIP BETWEEN MIL, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMS

When a malfunction is detected for the first time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.

When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MIL will come on. For details, refer to EC-48, "
Tw o Tr ip D e t e c t i o n
Logic" .

The MIL will go off after the vehicle is driven 3 times (driving pattern B) with no malfunction. The drive is
counted only when the recorded driving pattern is met (as stored in the ECM). If another malfunction
occurs while counting, the counter will reset.

The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A)
without the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and
Fuel Injection System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times
(driving pattern C) without the same malfunction recurring. The “TIME” in “SELF-DIAGNOSTIC
RESULTS” mode of CONSULT-II will count the number of times the vehicle is driven.

The 1st trip DTC is not displayed when the self-diagnosis results in OK for the 2nd trip.
PBIA3905E

BASIC SERVICE PROCEDURE
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Revision: October 20052005 QX56
Idle Mixture Ratio AdjustmentUBS00KZW
PREPARATION
1. Make sure that the following parts are in good order.

Battery

Ignition system

Engine oil and coolant levels

Fuses

ECM harness connector

Vacuum hoses

Air intake system
(Oil filler cap, oil level gauge, etc.)

Fuel pressure

Engine compression

Throttle valve

Evaporative emission system
2. On air conditioner equipped models, checks should be carried out while the air conditioner is OFF.
3. Checks should be carried out while selector lever is in P or N position.
4. When measuring CO percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5. Turn off headlamp, heater blower, rear window defogger.
6. Keep front wheels pointed straight ahead.