2001 INFINITI QX4 coolant

Alphabetical & P No. Index for DTCNBEC0001ALPHABETICAL INDEX FOR DTCNBEC0001S01
Items
(CONSULT-II screen terms)DTC*1 Reference page
Unable to access ECM Ð EC-117
ABSL PRES SEN/CIRC P0105 EC-158
AIR TEMP SEN/CIRC P0110 EC-164
A/T 1ST GR FNCTN P0731 AT-136
A/T 2ND GR FNCTN P0732 AT-143
A/T 3RD GR FNCTN P0733 AT-151
A/T 4TH GR FNCTN P0734 AT-157
A/T COMM LINE P0600*2 EC-440
A/T DIAG COMM LINE P1605 EC-603
A/T TCC S/V FNCTN P0744 AT-170
ATF TEMP SEN/CIRC P0710 AT-116
CAM PS/CIRC (PHS) P0340 EC-342
CLOSED LOOP-B1 P1148 EC-491
CLOSED LOOP-B2 P1168 EC-491
CLOSED TP SW/CIRC P0510 EC-431
COOLANT T SEN/CIRC*3 P0115 EC-169
*COOLANT T SEN/CIRC P0125 EC-187
CPS/CIRC (POS) COG P1336 EC-517
CPS/CIRCUIT (POS) P0335 EC-334
CPS/CIRCUIT (REF) P1335 EC-510
CYL 1 MISFIRE P0301 EC-320
CYL 2 MISFIRE P0302 EC-320
CYL 3 MISFIRE P0303 EC-320
CYL 4 MISFIRE P0304 EC-320
CYL 5 MISFIRE P0305 EC-320
CYL 6 MISFIRE P0306 EC-320
ECMP0605 EC-444
ENGINE SPEED SIG P0725 AT-130
ENG OVER TEMP P0217 EC-314
ENG OVER TEMP P1217 LC-24
EVAP GROSS LEAK P0455 EC-394
EVAP PURG FLOW/MON P1447 EC-561
EVAP SYS PRES SEN P0450 EC-381
EVAP SMALL LEAK P0440 EC-352
EVAP VERY SMALL LEAK P1441 EC-526
TROUBLE DIAGNOSIS Ð INDEX
Alphabetical & P No. Index for DTC
EC-8

P NO. INDEX FOR DTC=NBEC0001S02
DTC*1Items
(CONSULT-II screen terms)Reference page
Ð Unable to access ECM EC-117
P0000NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.Ð
P0100 MAF SEN/CIRCUIT*3 EC-150
P0105 ABSL PRES SEN/CIRC EC-158
P0110 AIR TEMP SEN/CIRC EC-164
P0115 COOLANT T SEN/CIRC*3 EC-169
P0120 THRTL POS SEN/CIRC*3 EC-174
P0125 *COOLANT T SEN/CIRC EC-187
P0130 HO2S1 (B1) EC-192
P0131 HO2S1 (B1) EC-202
P0132 HO2S1 (B1) EC-210
P0133 HO2S1 (B1) EC-218
P0134 HO2S1 (B1) EC-231
P0135 HO2S1 HTR (B1) EC-240
P0137 HO2S2 (B1) EC-247
P0138 HO2S2 (B1) EC-257
P0139 HO2S2 (B1) EC-267
P0140 HO2S2 (B1) EC-277
P0141 HO2S2 HTR (B1) EC-286
P0150 HO2S1 (B2) EC-192
P0151 HO2S1 (B2) EC-202
P0152 HO2S1 (B2) EC-210
P0153 HO2S1 (B2) EC-218
P0154 HO2S1 (B2) EC-231
P0155 HO2S1 HTR (B2) EC-240
P0157 HO2S2 (B2) EC-247
P0158 HO2S2 (B2) EC-257
P0159 HO2S2 (B2) EC-267
P0160 HO2S2 (B2) EC-277
P0161 HO2S2 HTR (B2) EC-286
P0171 FUEL SYS-LEAN/BK1 EC-294
P0172 FUEL SYS-RICH/BK1 EC-302
P0174 FUEL SYS-LEAN/BK2 EC-294
P0175 FUEL SYS-RICH/BK2 EC-302
P0180 FUEL TEMP SEN/CIRC EC-309GI
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TROUBLE DIAGNOSIS Ð INDEX
Alphabetical & P No. Index for DTC (Cont'd)
EC-11

Tool name
(Kent-Moore No.)Description
Socket wrench
NT705
Removing and installing engine coolant tempera-
ture sensor
Oxygen sensor thread
cleaner
(J-43897-18)
(J-43897-12)
NT828
Reconditioning the exhaust system threads before
installing a new oxygen sensor. Use with anti-seize
lubricant shown below.
a: J-43897-18 18 mm diameter with pitch 1.5
mm, for Zirconia Oxygen Sensor
b: J-43897-12 12 mm diameter with pitch 1.25
mm, for Titania Oxygen Sensor
Anti-seize lubricant
(Permatex
TM133AR or
equivalent meeting MIL
specification MIL-A-907)
NT779
Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
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PREPARATION
Commercial Service Tools (Cont'd)
EC-19

System ChartNBEC0013
Input (Sensor) ECM Function Output (Actuator)
ICamshaft position sensor (PHASE)
ICrankshaft position sensor (REF)
IMass air flow sensor
IEngine coolant temperature sensor
IHeated oxygen sensor 1 (front)
IIgnition switch
IThrottle position sensor
IClosed throttle position switch*3
IPark/neutral position (PNP) switch
IAir conditioner switch
IKnock sensor
IIntake air temperature sensor
IAbsolute pressure sensor
IEVAP control system pressure sensor*1
IBattery voltage
IPower steering oil pressure switch
IVehicle speed sensor
IFuel tank temperature sensor*1
ICrankshaft position sensor (POS)
IHeated oxygen sensor 2 (rear)*2
ITCM (Transmission control module)
IRefrigerant pressure sensor
IElectrical load
IFuel level sensor*1Fuel injection & mixture ratio control Injectors
Electronic ignition system Power transistor
Idle air control system IACV-AAC valve
Fuel pump control Fuel pump relay
On board diagnostic system MIL (On the instrument panel)
Swirl control valve controlSwirl control valve control solenoid
valve
Power valve control VIAS control solenoid valve
Heated oxygen sensor 1 heater (front) con-
trolHeated oxygen sensor 1 heater
(front)
Heated oxygen sensor 2 heater (rear) controlHeated oxygen sensor 2 heater
(rear)
EVAP canister purge flow controlEVAP canister purge volume con-
trol solenoid valve
Air conditioning cut control Air conditioner relay
ON BOARD DIAGNOSIS for EVAP systemIEVAP canister vent control valve
IVacuum cut valve bypass valve
*1: These sensors are not used to control the engine system. They are used only for the on board diagnosis.
*2: This sensor is not used to control the engine system under normal conditions.
*3: This switch will operate in place of the throttle position sensor to control EVAP parts if the sensor malfunctions.GI
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ENGINE AND EMISSION CONTROL OVERALL SYSTEM
System Chart
EC-27

Multiport Fuel Injection (MFI) System
DESCRIPTIONNBEC0014Input/Output Signal ChartNBEC0014S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed (POS signal)
Fuel injec-
tion & mix-
ture ratio
controlInjectors Crankshaft position sensor (REF) Engine speed (REF signal)
Camshaft position sensor (PHASE) Piston position
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 (front) Density of oxygen in exhaust gas
Throttle position sensorThrottle position
Throttle valve idle position
Park/neutral position (PNP) switch Gear position
Vehicle speed sensor Vehicle speed
Ignition switch Start signal
Air conditioner switch Air conditioner operation
Knock sensor Engine knocking condition
Battery Battery voltage
Absolute pressure sensor Ambient air barometric pressure
Power steering oil pressure switch Power steering operation
Heated oxygen sensor 2 (rear)* Density of oxygen in exhaust gas
*: Under normal conditions, this sensor is not for engine control operation.
Basic Multiport Fuel Injection SystemNBEC0014S02The 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 CompensationNBEC0014S03In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.

IDuring warm-up
IWhen starting the engine
IDuring acceleration
IHot-engine operation
IWhen selector lever is changed from ªNº to ªDº
IHigh-load, high-speed operation

IDuring deceleration
IDuring high engine speed operation
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Multiport Fuel Injection (MFI) System
EC-28

Mixture Ratio Feedback Control (Closed loop control)NBEC0014S04
SEF336WA
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission con-
trol. The warm-up three way catalyst can then better reduce CO, HC and NOx emissions. This system uses
a heated oxygen sensor 1 (front) in the exhaust manifold to monitor if the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about the
heated oxygen sensor 1 (front), refer to EC-192. This maintains the mixture ratio within the range of stoichio-
metric (ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 (rear) is located downstream of the warm-up three way catalyst. Even if the switch-
ing characteristics of the heated oxygen sensor 1 (front) shift, the air-fuel ratio is controlled to stoichiometric
by the signal from the heated oxygen sensor 2 (rear).
Open Loop ControlNBEC0014S05The 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.
IDeceleration and acceleration
IHigh-load, high-speed operation
IMalfunction of heated oxygen sensor 1 (front) or its circuit
IInsufficient activation of heated oxygen sensor 1 (front) at low engine coolant temperature
IHigh engine coolant temperature
IDuring warm-up
IAfter shifting from ªNº to ªDº
IWhen starting the engine
Mixture Ratio Self-learning ControlNBEC0014S06The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxy-
gen sensor 1 (front). This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio
as close to the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily con-
trolled as originally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and char-
acteristic changes during operation (i.e., 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 ªinjection pulse durationº to automatically compensate for the difference between
the two ratios.
ªFuel trimº refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
ªShort term fuel trimº is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from the heated oxygen sensor 1 (front) indicates whether the mixture ratio is RICH or LEAN
compared to the theoretical 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.
ªLong term fuel trimº is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
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ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Multiport Fuel Injection (MFI) System (Cont'd)
EC-29

Fuel Injection TimingNBEC0014S07
SEF179U
Two types of systems are used.
Sequential Multiport Fuel Injection System
NBEC0014S0701Fuel 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
NBEC0014S0702Fuel is injected simultaneously into all six cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The six 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-offNBEC0014S08Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Electronic Ignition (EI) System
DESCRIPTIONNBEC0015Input/Output Signal ChartNBEC0015S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed (POS signal)
Ignition
timing con-
trolPower transistor Crankshaft position sensor (REF) Engine speed (REF signal)
Camshaft position sensor (PHASE) Piston position
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensorThrottle position
Throttle valve idle position
Vehicle speed sensor Vehicle speed
Ignition switch Start signal
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery Battery voltage
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Multiport Fuel Injection (MFI) System (Cont'd)
EC-30

System DescriptionNBEC0015S02
SEF742M
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. This data forms the map shown.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Com-
puting this information, ignition signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
A ÉBTDC
During the following conditions, the ignition timing is revised by the ECM according to the other data stored
in the ECM.
IAt starting
IDuring warm-up
IAt idle
IAt low battery voltage
IDuring acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Air Conditioning Cut Control
DESCRIPTIONNBEC0016Input/Output Signal ChartNBEC0016S01
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch Air conditioner ªONº signal
Air conditioner
cut controlAir conditioner relay Throttle position sensor Throttle valve opening angle
Crankshaft position sensor (POS) Engine speed (POS signal)
Crankshaft position sensor (REF) Engine speed (REF signal)
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Vehicle speed sensor Vehicle speed
Refrigerant pressure sensor Refrigerant pressure
Power steering oil pressure switch Power steering operation
System DescriptionNBEC0016S02This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
IWhen the accelerator pedal is fully depressed.
IWhen cranking the engine.
IAt high engine speeds.
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ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Electronic Ignition (EI) System (Cont'd)
EC-31