exh INFINITI FX35 2004 User Guide

OVERHEATING CAUSE ANALYSIS
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Revision: 2004 November 2004 FX35/FX45
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartABS004UZ
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat stuck closed —
Damaged finsDust contamination or
paper clogging
Physical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Reduced air flowCooling fan does not oper-
ate
Fan assembly — High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio—— —
Poor engine coolant quality — Engine coolant density —
Insufficient engine coolantEngine coolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration

CO-32
[VK45DE]
OVERHEATING CAUSE ANALYSIS
Revision: 2004 November 2004 FX35/FX45
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartABS006JF
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat stuck closed —
Damaged finsDust contamination or
paper clogging
Physical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Reduced air flowCooling fan does not oper-
ate
Fan assembly — High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio—— —
Poor engine coolant quality — Engine coolant density —
Insufficient engine coolantEngine coolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration

EC-28
[VQ35DE]
PREPARATION
Revision: 2004 November 2004 FX35/FX45
Commercial Service ToolsABS006K3
Tool name
(Kent-Moore No.)Description
Leak detector
i.e.: (J-41416)Locating the EVAP leak
EVAP service port
adapter
i.e.: (J-41413-OBD)Applying positive pressure through EVAP service
port
Fuel filler cap adapter
i.e.: (MLR-8382)Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant
temperature sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12)Reconditioning the exhaust system threads
before installing a new oxygen sensor. Use with
anti-seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for
Zirconia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for
Titania Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL
specification MIL-A-
907)Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
S-NT703
S-NT704
S-NT815
S-NT705
AEM488
S-NT779

EC-32
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2004 November 2004 FX35/FX45
Multiport Fuel Injection (MFI) SystemABS006K7
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*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.


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


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
Heated oxygen 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
Air conditioner switch*
2Air conditioner operation
Wheel sensor*
2Vehicle speed

ENGINE CONTROL SYSTEM
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Revision: 2004 November 2004 FX35/FX45
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst 1 can then better reduce CO, HC and NOx emissions. This system uses heated oxy-
gen sensor 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 heated oxygen
sensor 1, refer to EC-205
. 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 three way catalyst 1. Even if the switching characteris-
tics of heated oxygen 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 heated oxygen sensor 1 or its circuit

Insufficient activation of heated oxygen 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 the mixture ratio signal transmitted from heated oxygen
sensor 1. 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 controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
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 “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared 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 compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 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.
“Long term fuel trim” 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.
PBIB0121E

EC-72
[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2004 November 2004 FX35/FX45
*: Maintains conditions just before switching to open loop.
To check the heated oxygen sensor 1 function, start engine in the Diagnostic Test Mode II and warm it up until
engine coolant temperature indicator points to the middle of the gauge.
Next run engine at about 2,000 rpm for about 2 minutes under no-load conditions. Then make sure that the
MIL comes ON more than 5 times within 10 seconds with engine running at 2,000 rpm under no-load.
OBD System Operation ChartABS006KN
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-53, "
Two Trip Detection
Logic" .

The MIL will go off after the vehicle is driven 3 times 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.
SUMMARY CHART
For details about patterns B and C under “Fuel Injection System” and “Misfire”, see EC-74 .
For details about patterns A and B under Other, see EC-76
.
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.MIL Fuel mixture condition in the exhaust gas Air fuel ratio feedback control condition
ON Lean
Closed loop system
OFF Rich
*Remains ON or OFF Any condition Open loop system
Items Fuel Injection System Misfire Other
MIL (goes off) 3 (pattern B) 3 (pattern B) 3 (pattern B)
DTC, Freeze Frame Data (no
display)80 (pattern C) 80 (pattern C) 40 (pattern A)
1st Trip DTC (clear) 1 (pattern C), *1 1 (pattern C), *1 1 (pattern B)
1st Trip Freeze Frame Data
(clear)*1, *2 *1, *2 1 (pattern B)

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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Revision: 2004 November 2004 FX35/FX45
RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS FOR “MISFIRE
” , “FUEL INJECTION SYSTEM”
*1: When the same malfunction is
detected in two consecutive trips,
MIL will light up.*2: MIL will go off after vehicle is driven
3 times (pattern B) without any mal-
functions.*3: When the same malfunction is
detected in two consecutive trips, the
DTC and the freeze frame data will
be stored in ECM.
*4: The DTC and the freeze frame data
will not be displayed any longer after
vehicle is driven 80 times (pattern C)
without the same malfunction. (The
DTC and the freeze frame data still
remain in ECM.)*5: When a malfunction is detected for
the first time, the 1st trip DTC and
the 1st trip freeze frame data will be
stored in ECM.*6: The 1st trip DTC and the 1st trip
freeze frame data will be cleared at
the moment OK is detected.
*7: When the same malfunction is
detected in the 2nd trip, the 1st trip
freeze frame data will be cleared.*8: 1st trip DTC will be cleared when
vehicle is driven once (pattern C)
without the same malfunction after
DTC is stored in ECM.
SEF392S

EC-74
[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2004 November 2004 FX35/FX45
EXPLANATION FOR DRIVING PATTERNS FOR “MISFIRE TION>”, “FUEL INJECTION SYSTEM”

Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.

The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.

The B counter will be counted up when driving pattern B is satisfied without any malfunction.

The MIL will go off when the B counter reaches 3. (*2 in “OBD SYSTEM OPERATION CHART”)

Driving pattern C means the vehicle operation as follows:
The following conditions should be satisfied at the same time:
Engine speed: (Engine speed in the freeze frame data) ±375 rpm
Calculated load value: (Calculated load value in the freeze frame data) x (1±0.1) [%]
Engine coolant temperature (T) condition:

When the freeze frame data shows lower than 70°C (158°F), T should be lower than 70°C (158°F).

When the freeze frame data shows higher than or equal to 70°C (158°F), T should be higher than or equal
to 70°C (158°F).
Example:
If the stored freeze frame data is as follows:
Engine speed: 850 rpm, Calculated load value: 30%, Engine coolant temperature: 80°C (176°F)
To be satisfied with driving pattern C, the vehicle should run under the following conditions:
Engine speed: 475 - 1,225 rpm, Calculated load value: 27 - 33%, Engine coolant temperature: more than 70°C
(158°F)

The C counter will be cleared when the malfunction is detected regardless of vehicle conditions above.

The C counter will be counted up when vehicle conditions above is satisfied without the same malfunction.

The DTC will not be displayed after C counter reaches 80.

The 1st trip DTC will be cleared when C counter is counted once without the same malfunction after DTC
is stored in ECM.

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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Revision: 2004 November 2004 FX35/FX45
RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS EXCEPT FOR
“MISFIRE ”, “FUEL INJECTION SYSTEM”
*1: When the same malfunction is
detected in two consecutive trips,
MIL will light up.*2: MIL will go off after vehicle is driven
3 times (pattern B) without any mal-
functions.*3: When the same malfunction is
detected in two consecutive trips, the
DTC and the freeze frame data will
be stored in ECM.
*4: The DTC and the freeze frame data
will not be displayed any longer after
vehicle is driven 40 times (pattern A)
without the same malfunction.
(The DTC and the freeze frame data
still remain in ECM.)*5: When a malfunction is detected for
the first time, the 1st trip DTC and
the 1st trip freeze frame data will be
stored in ECM.*6: 1st trip DTC will be cleared after
vehicle is driven once (pattern B)
without the same malfunction.
*7: When the same malfunction is
detected in the 2nd trip, the 1st trip
freeze frame data will be cleared.
SEF393SD

EC-76
[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2004 November 2004 FX35/FX45
EXPLANATION FOR DRIVING PATTERNS EXCEPT FOR “MISFIRE DETERIORATION>”, “FUEL INJECTION SYSTEM”


The A counter will be cleared when the malfunction is detected regardless of (1) - (4).

The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.

The DTC will not be displayed after the A counter reaches 40.

Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.

The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.

The B counter will be counted up when driving pattern B is satisfied without any malfunctions.

The MIL will go off when the B counter reaches 3 (*2 in OBD SYSTEM OPERATION CHART).
AEC574