Ac system INFINITI QX4 2001 Factory Service Manual

TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL/T TEMP
SENIChange the fuel tank temperature using CONSULT-II.
VENT
CONTROL/VIIgnition switch: ON
(Engine stopped)
ITurn solenoid valve ªONº and
ªOFFº with the CONSULT-II and
listen to operating sound.Solenoid valve makes an operating
sound.IHarness and connector
ISolenoid valve
VC/V BYPASS/VIIgnition switch: ON
(Engine stopped)
ITurn solenoid valve ªONº and
ªOFFº with the CONSULT-II and
listen to operating sound.Solenoid valve makes an operating
sound.IHarness and connector
ISolenoid valve
TARGET INT/V
TIMIEngine: After warming up, hold
engine speed at 1,500 to 2,000
rpm.
IChange the intake valve timing
using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.IHarness and connector
IIntake valve timing control sole-
noid valve
DTC & SRT CONFIRMATION MODENBEC0034S08SRT STATUS ModeNBEC0034S0801For details, refer to ªSYSTEM READINESS TEST (SRT) CODEº,
EC-61.
SRT Work Support ModeNBEC0034S0803This mode enables a technician to drive a vehicle to set the SRT
while monitoring the SRT status.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-92

DTC Work Support ModeNBEC0034S0802
Test mode Test item Condition Reference page
EVAPORATIVE SYSTEMEVAP SML LEAK P0440
Refer to corresponding
trouble diagnosis for
DTC.EC-352
EVAP VERY SML LEAK P1441 EC-526
PURG VOL CN/V P1444 EC-541
PURGE FLOW P1447 EC-561
VC CUT/V BP/V P1491 EC-591
HEATED OXYGEN SEN-
SOR 1 (FRONT)HO2S1 (B1) P0130 EC-192
HO2S1 (B1) P0131 EC-202
HO2S1 (B1) P0132 EC-210
HO2S1 (B1) P0133 EC-218
HO2S1 (B2) P0150 EC-192
HO2S1 (B2) P0151 EC-202
HO2S1 (B2) P0152 EC-210
HO2S1 (B2) P0153 EC-218
HEATED OXYGEN SEN-
SOR 2 (REAR)HO2S2 (B1) P0137 EC-247
HO2S2 (B1) P0138 EC-257
HO2S2 (B1) P0139 EC-267
HO2S2 (B2) P0157 EC-247
HO2S2 (B2) P0158 EC-257
HO2S2 (B2) P0159 EC-267
SEF705Y
SEF707X
REAL TIME DIAGNOSIS IN DATA MONITOR MODE
(RECORDING VEHICLE DATA)
NBEC0034S10CONSULT-II has two kinds of triggers and they can be selected by
touching ªSETTINGº in ªDATA MONITORº mode.
1) ªAUTO TRIGº (Automatic trigger):
IThe malfunction will be identified on the CONSULT-II screen in
real time.
In other words, DTC/1st trip DTC and malfunction item will be
displayed if the malfunction is detected by ECM.
At the moment a malfunction is detected by ECM, ªMONITORº
in ªDATA MONITORº screen is changed to ªRecording Data ...
xx%º as shown at left, and the data after the malfunction detec-
tion is recorded. Then when the percentage reached 100%,
ªREAL-TIME DIAGº screen is displayed. If ªSTOPº is touched
on the screen during ª Recording Data ... xx%º, ªREAL-TIME
DIAGº screen is also displayed.
The recording time after the malfunction detection and the
recording speed can be changed by ªTRIGGER POINTº and
ªRecording Speedº. Refer to CONSULT-II OPERATION
MANUAL.
2) ªMANU TRIGº (Manual trigger):
IDTC/1st trip DTC and malfunction item will not be displayed
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-93

automatically on CONSULT-II screen even though a malfunc-
tion is detected by ECM.
DATA MONITOR can be performed continuously even though
a malfunction is detected.
Use these triggers as follows:
1) ªAUTO TRIGº
IWhile trying to detect the DTC/1st trip DTC by performing the
ªDTC Confirmation Procedureº, be sure to select to ªDATA
MONITOR (AUTO TRIG)º mode. You can confirm the malfunc-
tion at the moment it is detected.
IWhile narrowing down the possible causes, CONSULT-II
should be set in ªDATA MONITOR (AUTO TRIG)º mode, espe-
cially in case the incident is intermittent.
When you are inspecting the circuit by gently shaking (or twist-
ing) the suspicious connectors, components and harness in
the ªDTC Confirmation Procedureº, the moment a malfunction
is found the DTC/1st trip DTC will be displayed. (Refer to
GI-36, ªIncident Simulation Testsº.)
2) ªMANU TRIGº
IIf the malfunction is displayed as soon as ªDATA MONITORº
is selected, reset CONSULT-II to ªMANU TRIGº. By selecting
ªMANU TRIGº you can monitor and store the data. The data
can be utilized for further diagnosis, such as a comparison with
the value for the normal operating condition.
SEF714Y
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-94

SEF139P
Generic Scan Tool (GST)=NBEC0035DESCRIPTIONNBEC0035S01Generic Scan Tool (OBDII scan tool) complying with SAE J1978
has 8 different functions explained on the next page.
ISO9141 is used as the protocol.
The name ªGSTº or ªGeneric Scan Toolº is used in this service
manual.
SEF941Y
GST INSPECTION PROCEDURENBEC0035S021. Turn ignition switch OFF.
2. Connect GST to data link connector, which is located under LH
dash panel near the fuse box cover.
SEF398S
3. Turn ignition switch ON.
4. Enter the program according to instruction on the screen or in
the operation manual.
(*: Regarding GST screens in this section, sample screens are
shown.)
SEF416S
5. Perform each diagnostic mode according to each service pro-
cedure.
For further information, see the GST Operation Manual of the
tool maker.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Generic Scan Tool (GST)
EC-95

FUNCTIONNBEC0035S03
Diagnostic test mode Function
MODE 1 READINESS TESTSThis mode gains access to current emission-related data values, including analog
inputs and outputs, digital inputs and outputs, and system status information.
MODE 2 (FREEZE DATA)This mode gains access to emission-related data value which were stored by ECM
during the freeze frame. [For details, refer to ªFreeze Frame Dataº (EC-85).]
MODE 3 DTCsThis mode gains access to emission-related power train trouble codes which were
stored by ECM.
MODE 4 CLEAR DIAG INFOThis mode can clear all emission-related diagnostic information. This includes:
IClear number of diagnostic trouble codes (MODE 1)
IClear diagnostic trouble codes (MODE 3)
IClear trouble code for freeze frame data (MODE 1)
IClear freeze frame data (MODE 2)
IReset status of system monitoring test (MODE 1)
IClear on board monitoring test results (MODE 6 and 7)
MODE 6 (ON BOARD TESTS)This mode accesses the results of on board diagnostic monitoring tests of specific
components/systems that are not continuously monitored.
MODE 7 (ON BOARD TESTS)This mode enables the off board test drive to obtain test results for emission-related
powertrain components/systems that are continuously monitored during normal driving
conditions.
MODE 8 ÐThis mode can close EVAP system in ignition switch ªONº position (Engine stopped).
When this mode is performed, the following parts can be opened or closed.
IEVAP canister vent control valve open
IVacuum cut valve bypass valve closed
In the following conditions, this mode cannot function.
ILow ambient temperature
ILow battery voltage
IEngine running
IIgnition switch ªOFFº
ILow fuel temperature
IToo much pressure is applied to EVAP system
MODE 9 (CALIBRATION ID)This mode enables the off-board test device to request specific vehicle information
such as Vehicle Identification Number (VIN) and Calibration IDs.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Generic Scan Tool (GST) (Cont'd)
EC-96

MEF036D
IntroductionNBEC0036
SEF233G
SEF234G
The engine has an ECM to control major systems such as fuel
control, ignition control, idle air control system, etc. The ECM
accepts input signals from sensors and instantly drives actuators.
It is essential that both input and output signals are proper and
stable. At the same time, it is important that there are no problems
such as vacuum leaks, fouled spark plugs, or other problems with
the engine.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the problems. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the ªWork Flowº on EC-99.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, espe-
cially intermittent ones. Find out what symptoms are present and
under what conditions they occur. A ªDiagnostic Worksheetº like the
example on next page should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
SEF907L
DIAGNOSTIC WORKSHEETNBEC0036S01There are many operating conditions that lead to the malfunction
of engine components. A good grasp of such conditions can make
trouble-shooting faster and more accurate.
In general, each customer feels differently about a problem. It is
important to fully understand the symptoms or conditions for a
customer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MIL to come on steady or blink and
DTC to be detected. Examples:
IVehicle ran out of fuel, which caused the engine to misfire.
IFuel filler cap was left off or incorrectly screwed on, allowing
fuel to evaporate into the atmosphere.
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TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction
EC-97

Work FlowNBEC0037
SEF510ZF
*1 EC-117
*2 If time data of ªSELF-DIAG
RESULTSº is other than ª0º or
ª[1t]º, perform ªTROUBLE DIAG-
NOSIS FOR INTERMITTENT
INCIDENTº, EC-140.
*3 If the incident cannot be verified,
perform ªTROUBLE DIAGNOSIS
FOR INTERMITTENT INCIDENTº,
EC-140.*4 If the on board diagnostic system
cannot be performed, check main
power supply and ground circuit.
Refer to ªTROUBLE DIAGNOSIS
FOR POWER SUPPLYº, EC-142.
*5 If malfunctioning part cannot bedetected, perform ªTROUBLE
DIAGNOSIS FOR INTERMIT-
TENT INCIDENTº, EC-140.
*6 EC-66
*7 EC-136
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TROUBLE DIAGNOSIS Ð INTRODUCTION
Work Flow
EC-99

DESCRIPTION FOR WORK FLOWNBEC0037S01
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using
the ªDIAGNOSTIC WORK SHEETº, EC-98.
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II or GST) the (1st trip) DTC
and the (1st trip) freeze frame data, then erase the DTC and the data. (Refer to EC-72.) The (1st trip) DTC and
the (1st trip) freeze frame data can be used when duplicating the incident at STEP III & IV.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
Study the relationship between the cause, specified by (1st trip) DTC, and the symptom described by the cus-
tomer. (The ªSymptom Matrix Chartº will be useful. See EC-118.)
Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The ªDIAGNOSTIC WORK SHEETº and the freeze frame data are useful to verify the incident. Connect CON-
SULT-II to the vehicle in DATA MONITOR (AUTO TRIG) mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the (1st trip) DTC by driving in (or performing) the ªDTC Confirmation Procedureº. Check and read
the (1st trip) DTC and (1st trip) freeze frame data by using CONSULT-II or GST.
During the (1st trip) DTC verification, be sure to connect CONSULT-II to the vehicle in DATA MONITOR (AUTO
TRIG) mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
In case the ªDTC Confirmation Procedureº is not available, perform the ªOverall Function Checkº instead. The
(1st trip) DTC cannot be displayed by this check, however, this simplified ªcheckº is an effective alternative.
The ªNGº result of the ªOverall Function Checkº is the same as the (1st trip) DTC detection.
STEP VTake the appropriate action based on the results of STEP I through IV.
If the malfunction code is indicated, proceed to TROUBLE DIAGNOSIS FOR DTC PXXXX.
If the normal code is indicated, proceed to the BASIC INSPECTION. (Refer to EC-101.) If CONSULT-II is
available, perform ªDATA MONITOR (SPEC)º mode with CONSULT-II and proceed to the ªTROUBLE DIAGNO-
SIS Ð SPECIFICATION VALUEº, EC-136. (If malfunction is detected, proceed to ªREPAIR REPLACEº.) Then
perform inspections according to the Symptom Matrix Chart. (Refer to EC-118.)
STEP VIIdentify where to begin diagnosis based on the relationship study between symptom and possible causes.
Inspect the system for mechanical binding, loose connectors or wiring damage using (tracing) ªHarness Layoutsº.
Gently shake the related connectors, components or wiring harness with CONSULT-II set in ªDATA MONITOR
(AUTO TRIG)º mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CON-
SULT-II. Refer to EC-122, 127.
The ªDiagnostic Procedureº in EC section contains a description based on open circuit inspection. A short circuit
inspection is also required for the circuit check in the Diagnostic Procedure. For details, refer to GI-27, ªCircuit
Inspectionº.
Repair or replace the malfunction parts.
If malfunctioning part cannot be detected, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº,
EC-140.
STEP VIIOnce you have repaired the circuit or replaced a component, you need to run the engine in the same conditions
and circumstances which resulted in the customer's initial complaint.
Perform the ªDTC Confirmation Procedureº and confirm the normal code [DTC No. P0000] is detected. If the
incident is still detected in the final check, perform STEP VI by using a different method from the previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already fixed) (1st trip) DTC in
ECM and TCM (Transmission control module). (Refer to EC-72.)
TROUBLE DIAGNOSIS Ð INTRODUCTION
Work Flow (Cont'd)
EC-100

23 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
750±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
750±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 28.
NG©GO TO 24.
24 REPLACE IACV-AAC VALVE
Replace IACV-AAC valve.
©GO TO 25.
25 PERFORM IDLE AIR VOLUME LEARNING
Refer to ªIdle Air Volume Learningº, EC-57.
Which is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©GO TO 26.
INCMP©1. Follow the construction of ªIdle Air Volume Learningº.
2. GO TO 22.
26 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
750±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
750±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 28.
NG©GO TO 27.
27 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but this is rarely
the case.)
2. Perform initialization of IVIS (NATS) system and registration of IVIS (NATS) ignition key IDs. Refer to ªIVIS (INFINITI
VEHICLE IMMOBILIZER SYSTEM Ð NATS)º, EC-74.
©GO TO 22.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Basic Inspection (Cont'd)
EC-113

31 PERFORM IDLE AIR VOLUME LEARNING
Refer to ªIdle Air Volume Learningº, EC-57.
Which is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©GO TO 32.
INCMP©1. Follow the construction of ªIdle Air volume Learningº.
2. GO TO 31.
32 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
750±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
750±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 34.
NG©GO TO 33.
33 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function.
(ECM may be the cause of a problem, but this is rarely the case.)
2. Perform initialization of NVIS (NATS) system and registration of NVIS (NATS) ignition key IDs. Refer to ªNVIS (NISSAN
VEHICLE IMMOBILIZER SYSTEM Ð NATS)º, EC-74.
©GO TO 31.
34 CHECK IGNITION TIMING AGAIN
Check ignition timing again. Refer to Test No. 30.
OK or NG
OK©GO TO 36.
NG©GO TO 35.
35 CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-29, ªInstallationº.
OK or NG
OK©GO TO 33.
NG©1. Repair the timing chain installation.
2. GO TO 31.
36 ERASE UNNECESSARY DTC
After this inspection, unnecessary DTC No. might be displayed.
Erase the stored memory in ECM and TCM (Transmission control module).
Refer to ªHow to Erase Emission-Related Diagnostic Informationº, EC-72 and AT-35, ªHOW TO ERASE DTCº.
©INSPECTION END
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Basic Inspection (Cont'd)
EC-115