2001 INFINITI QX4 light

SEF943Y
SEF572X
b) Connect No. 1 ignition coil and No. 1 spark plug with suitable
high-tension wire as shown, and attach timing light clamp to
this wire.
c) Check ignition timing.
SEF311Q
Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment
NBEC0028PREPARATIONNBEC0028S011) Make sure that the following parts are in good order.
IBattery
IIgnition system
IEngine oil and coolant levels
IFuses
IECM harness connector
IVacuum hoses
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BASIC SERVICE PROCEDURE
How to Check Idle Speed and Ignition Timing (Cont'd)
EC-43

9 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 4.
10 CHECK IGNITION TIMING
1. Start engine and warm it up to normal operating temperature.
2. Check ignition timing at idle using a timing light.
SEF572X
15ɱ5É BTDC (in ªPº or ªNº position)
OK or NG
OK©GO TO 18.
NG©GO TO 11.
11 CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-29, ªInstallationº.
OK or NG
OK©GO TO 9.
NG©1. Repair the timing chain installation.
2. GO TO 4.
12 CHECK IGNITION TIMING
1. Start engine and let it idle.
2. Check ignition timing at idle using a timing light.
SEF572X
15ɱ5É BTDC (in ªPº or ªNº position)
OK or NG
OK©GO TO 18.
NG©GO TO 13.
BASIC SERVICE PROCEDURE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-48

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Idle Air Volume LearningNBEC0642
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DESCRIPTIONNBEC0642S01ªIdle Air Volume Learningº is an operation to learn the idle air vol-
ume that keeps each engine within the specific range. It must be
performed under any of the following conditions:
IEach time IACV-AAC valve, throttle body or ECM is replaced.
IIdle speed or ignition timing is out of specification.
PRE-CONDITIONINGNBEC0642S02Before performing ªIdle Air Volume Learningº, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
IBattery voltage: More than 12.9V (At idle)
IEngine coolant temperature: 70 - 99ÉC (158 - 210ÉF)
IPNP switch: ON
IElectric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime running light systems, if
the parking brake is applied before the engine is started the
headlamp will not illuminate.
ICooling fan motor: Not operating
ISteering wheel: Neutral (Straight-ahead position)
IVehicle speed: Stopped
ITransmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until ªFLUID
TEMP SEº in ªDATA MONITORº mode of ªA/Tº system indi-
cates less than 0.9V.
For A/T models without CONSULT-II, drive vehicle for 10 min-
utes.
OPERATION PROCEDURENBEC0642S03With CONSULT-IINBEC0642S03011. Turn ignition switch ªONº and wait at least 1 second.
2. Turn ignition switch ªOFFº and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic ªPRE-CONDITION-
INGº (previously mentioned) are in good order.
5. Turn ignition switch ªOFFº and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Select ªIDLE AIR VOL LEARNº in ªWORK SUPPORTº mode.
8. Touch ªSTARTº and wait 20 seconds.
9. Make sure that ªCMPLTº is displayed on CONSULT-II screen.
If ªINCMPº is displayed, ªIdle Air Volume Learningº will not be
carried out successfully. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed 750±50 rpm (in ªPº or ªNº position)
Ignition timing 15ɱ5É BTDC (in ªPº or ªNº position)
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BASIC SERVICE PROCEDURE
Idle Air Volume Learning
EC-57

IntroductionNBEC0029The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:
Emission-related diagnostic information SAE Mode
Diagnostic Trouble Code (DTC) Mode 3 of SAE J1979
Freeze Frame data Mode 2 of SAE J1979
System Readiness Test (SRT) code Mode 1 of SAE J1979
1st Trip Diagnostic Trouble Code (1st Trip DTC) Mode 7 of SAE J1979
1st Trip Freeze Frame data
Test values and Test limits Mode 6 of SAE J1979
The above information can be checked using procedures listed in the table below.
X: Applicable Ð: Not applicable
DTC 1st trip DTCFreeze Frame
data1st trip Freeze
Frame dataSRT code Test value
CONSULT-II X X X X X Ð
GST X X*1 X Ð X X
*1: 1st trip DTCs for self-diagnoses concerning SRT items cannot be shown on the GST display.
The malfunction indicator lamp (MIL) on the instrument panel lights up when the same malfunction is detected
in two consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode. (Refer to EC-117.)
Two Trip Detection LogicNBEC0030When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in
the ECM memory. The MIL will not light up at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored
in the ECM memory, and the MIL lights up. The MIL lights up at the same time when the DTC is stored. <2nd
trip> The ªtripº in the ªTwo Trip Detection Logicº means a driving mode in which self-diagnosis is performed
during vehicle operation. Specific on board diagnostic items will cause the ECM to light up or blink the MIL,
and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
X: Applicable Ð: Not Exit
ItemsMIL DTC 1st trip DTC
1st trip 2nd trip
1st trip
displaying2nd trip
displaying1st trip
displaying2nd trip
displaying
BlinkingLighting
upBlinkingLighting
up
Misfire (Possible three way cata-
lyst damage) Ð DTC: P0300 -
P0306 (0701, 0605 Ð 0608) is
being detectedX ÐÐÐÐÐ X Ð
Misfire (Possible three way cata-
lyst damage) Ð DTC: P0300 -
P0306 (0701, 0605 Ð 0608) is
being detectedÐÐ X ÐÐ X ÐÐ
Closed loop control
Ð DTC: P1148 (0307), P1168
(0308)ÐXÐÐXÐXÐ
Fail-safe items (Refer to EC-117.) Ð X Ð Ð X*1 Ð X*1 Ð
Except above Ð Ð Ð X Ð X X Ð
*1: Except ªECMº
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Introduction
EC-59

Emission-related Diagnostic InformationNBEC0031DTC AND 1ST TRIP DTCNBEC0031S01The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunction is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL lights up when the same malfunction occurs in two con-
secutive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and
2nd trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or light up the MIL dur-
ing the 1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in ªHOW TO
ERASE EMISSION-RELATED DIAGNOSTIC INFORMATIONº, EC-72.
For malfunctions in which 1st trip DTCs are displayed, refer to EC-69. These items are required by legal
regulations to continuously monitor the system/component. In addition, the items monitored non-continuously
are also displayed on CONSULT-II.
1st trip DTC is specified in Mode 7 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL
and therefore does not warn the driver of a problem. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in ªWork Flowº procedure Step II, refer to EC-99. Then perform ªDTC Confirmation Proce-
dureº or ªOverall Function Checkº to try to duplicate the problem. If the malfunction is duplicated, the item
requires repair.
How to Read DTC and 1st Trip DTCNBEC0031S0101DTC and 1st trip DTC can be read by the following methods.
With CONSULT-II
With GST
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P1320, P0705, P0750, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
I1st trip DTC No. is the same as DTC No.
IOutput of a DTC indicates a malfunction. However, GST does not indicate whether the malfunction
is still occurring or has occurred in the past and has returned to normal. CONSULT-II can identify
malfunction status as shown below. Therefore, using CONSULT-II (if available) is recommended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown below. DTC or 1st trip DTC of a malfunc-
tion is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many times
the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be ª0º.
If a 1st trip DTC is stored in the ECM, the time data will be ª[1t]º.
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FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATANBEC0031S02The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant
temperature, short term fuel trim, long term fuel trim, engine speed, vehicle speed and absolute pressure at
the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Emission-related Diagnostic Information
EC-60

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.
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM Ð NATS)NBEC0031S08
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IIf the security indicator lights up with the ignition switch in the ªONº position or ªNATS MALFUNC-
TIONº is displayed on ªSELF-DIAG RESULTSº screen, perform self-diagnostic results mode with
CONSULT-II using NATS program card. Refer to ªIVIS (Infiniti Vehicle Immobilizer System Ð NATS)º
in EL section.
IConfirm no self-diagnostic results of IVIS (NATS) is displayed before touching ªERASEº in ªSELF-
DIAG RESULTSº mode with CONSULT-II.
IWhen replacing ECM, initialization of IVIS (NATS) system and registration of all IVIS (NATS) igni-
tion key IDs must be carried out with CONSULT-II using NATS program card.
Therefore, be sure to receive all keys from vehicle owner. Regarding the procedures of IVIS (NATS)
initialization and IVIS (NATS) ignition key ID registration, refer to CONSULT-II operation manual,
IVIS/NVIS.
Malfunction Indicator Lamp (MIL)
DESCRIPTIONNBEC0032
SEF217U
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON without the engine running. This is a bulb check.
IIf the MIL does not light up, refer to EL-114, ªWARNING LAMPSº or see EC-648.
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has detected an engine system malfunction.
On Board Diagnostic System FunctionNBEC0032S01The on board diagnostic system has the following two functions.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Emission-related Diagnostic Information (Cont'd)
EC-74

Diagnostic Test
ModeKEY and ENG.
StatusFunction Explanation of Function
Mode I Ignition switch in
ªONº position
Engine stopped
BULB CHECK This function checks the MIL bulb for damage (blown,
open circuit, etc.).
If the MIL does not come on, check MIL circuit.
Engine running
MALFUNCTION
WARNINGThis is a usual driving condition. When a malfunction is
detected twice in two consecutive driving cycles (two trip
detection logic), the MIL will light up to inform the driver
that a malfunction has been detected.
The following malfunctions will light up or blink the MIL in
the 1st trip.
ICoolant overtemperature enrichment protection
IªMisfire (Possible three way catalyst damage)º
IªClosed loop controlº
IFail-safe mode
Diagnostic Test Mode I Ð Bulb CheckNBEC0032S03In this mode, the MIL on the instrument panel should stay ON. If it remains OFF, check the bulb. Refer to
EL-114, ªWARNING LAMPSº or see EC-648.
Diagnostic Test Mode I Ð Malfunction WarningNBEC0032S04
MIL Condition
ON When the malfunction is detected or the ECM's CPU is malfunctioning.
OFF No malfunction.
OBD System Operation ChartNBEC0033RELATIONSHIP BETWEEN MIL, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMSNBEC0033S01IWhen 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.
IWhen 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 ªTwo Trip Detection Logicº on
EC-59.
IThe 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.
IThe 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 (driv-
ing pattern C) without the same malfunction recurring. The ªTIMEº in ªSELF-DIAGNOSTIC RESULTSº
mode of CONSULT-II will count the number of times the vehicle is driven.
IThe 1st trip DTC is not displayed when the self-diagnosis results in ªOKº for the 2nd trip.
SUMMARY CHARTNBEC0033S02
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)
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-75

RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS FOR
ªMISFIREº , ªFUEL INJECTION SYSTEMº
=NBEC0033S03
SEF392S
*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 malfunctions.
*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 framedata 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 tripfreeze 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.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
OBD System Operation Chart (Cont'd)
EC-77