2001 INFINITI QX4 Engine control

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
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Introduction
EC-59

For normal acceleration in low altitude areas
[less than 1,219 m (4,000 ft)]:For quick acceleration in low altitude
areas and high altitude areas
[over 1,219 m (4,000 ft)]:
Gear changeACCEL shift point
km/h (MPH)CRUISE shift point
km/h (MPH)km/h (MPH)
1st to 2nd 21 (13) 21 (13) 24 (15)
2nd to 3rd 37 (23) 26 (16) 40 (25)
3rd to 4th 53 (33) 44 (27) 64 (40)
4th to 5th 63 (39) 58 (36) 72 (45)
Suggested Maximum Speed in Each Gear
Downshift to a lower gear if the engine is not running smoothly, or if you need to accelerate.
Do not exceed the maximum suggested speed (shown below) in any gear. For level road driving, use the
highest gear suggested for that speed. Always observe posted speed limits and drive according to the road
conditions to ensure safe operation. Do not over-rev the engine when shifting to a lower gear as it may cause
engine damage or loss of vehicle control.
Gear km/h (MPH)
1st 50 (30)
2nd 89 (55)
3rd 128 (80)
4th Ð
5th Ð
TEST VALUE AND TEST LIMIT (GST ONLY Ð NOT APPLICABLE TO CONSULT-II)NBEC0031S04The following is the information specified in Mode 6 of SAE J1979.
The test value is a parameter used to determine whether a system/circuit diagnostic test is ªOKº or ªNGº while
being monitored by the ECM during self-diagnosis. The test limit is a reference value which is specified as the
maximum or minimum value and is compared with the test value being monitored.
Items for which these data (test value and test limit) are displayed are the same as SRT code items (30 test
items).
These data (test value and test limit) are specified by Test ID (TID) and Component ID (CID) and can be dis-
played on the GST screen.
X: Applicable Ð: Not applicable
SRT item Self-diagnostic test itemTest value (GST display)
Test limit Application
TID CID
C ATA LY S TThree way catalyst function
(Right bank)01H 01H Max. X
Three way catalyst function
(Left bank)03H 02H Max. X
EVAP SYSTEMEVAP control system
(Small leak)05H 03H Max. X
EVAP control system purge flow
monitoring06H 83H Min. X
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Emission-related Diagnostic Information (Cont'd)
EC-68

Items
(CONSULT-II screen terms)DTC*1 SRT codeTest value/ Test
limit
(GST only)1st trip DTC*1 Reference page
KNOCK SEN/CIRC-B1 P0325 Ð Ð Ð EC-328
CPS/CIRCUIT (POS) P0335 Ð Ð X EC-334
CAM PS/CIRC (PHS) P0340 Ð Ð X EC-342
TW CATALYST SYS-B1 P0420 X X X*2 EC-347
TW CATALYST SYS-B2 P0430 X X X*2 EC-347
EVAP SMALL LEAK P0440 X X X*2 EC-352
PURG VOLUME CONT/V P0443 Ð Ð X EC-367
VENT CONTROL VALVE P0446 Ð Ð X EC-374
EVAP SYS PRES SEN P0450 Ð Ð X EC-381
EVAP GROSS LEAK P0455 X X X*2 EC-394
FUEL LV SE (SLOSH) P0460 Ð Ð X EC-407
FUEL LEVEL SENSOR P0461 Ð Ð X EC-411
FUEL LEVEL SEN/CIRC P0464 Ð Ð X EC-413
VEH SPEED SEN/CIRC P0500 Ð Ð X EC-417
IACV/AAC VLV/CIRC P0505 Ð Ð X EC-422
CLOSED TP SW/CIRC P0510 Ð Ð X EC-431
A/T COMM LINE P0600 Ð Ð Ð EC-440
ECM P0605 Ð Ð X EC-444
PNP SW/CIRC P0705 Ð Ð X AT-111
ATF TEMP SEN/CIRC P0710 Ð Ð X AT-116
VEH SPD SEN/CIR AT P0720 Ð Ð X AT-124
ENGINE SPEED SIG P0725 Ð Ð X AT-130
A/T 1ST GR FNCTN P0731 Ð Ð X AT-136
A/T 2ND GR FNCTN P0732 Ð Ð X AT-143
A/T 3RD GR FNCTN P0733 Ð Ð X AT-151
A/T 4TH GR FNCTN P0734 Ð Ð X AT-157
TCC SOLENOID/CIRC P0740 Ð Ð X AT-165
A/T TCC S/V FNCTN P0744 Ð Ð X AT-170
L/PRESS SOL/CIRC P0745 Ð Ð X AT-174
SFT SOL A/CIRC P0750 Ð Ð X AT-180
SFT SOL B/CIRC P0755 Ð Ð X AT-189
INT/V TIM CONT-B1 P1110 Ð Ð X EC-446
INT/V TIM V/CIR-B1 P1111 Ð Ð XEC-451
SWIRL CONT SOL/V P1130 Ð Ð X EC-458
INT/V TIM CONT-B2 P1135 Ð Ð X EC-446
INT/V TIM V/CIR-B2 P1136 Ð Ð X EC-451
INTK TIM S/CIRC-B1 P1140 Ð Ð X EC-482
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Emission-related Diagnostic Information (Cont'd)
EC-71

Items
(CONSULT-II screen terms)DTC*1 SRT codeTest value/ Test
limit
(GST only)1st trip DTC*1 Reference page
INTK TIM S/CIRC-B2 P1145 Ð Ð X EC-482
CLOSED LOOP-B1 P1148 Ð Ð X EC-491
SWL CON VC SW/CIRC P1165 Ð Ð X EC-493
CLOSED LOOP-B2 P1168 Ð Ð X EC-491
ENG OVER TEMP P1217 Ð Ð X LC-24
IGN SIGNAL-PRIMARY P1320 Ð Ð X EC-499
CPS/CIRCUIT (REF) P1335 Ð Ð X EC-510
CPS/CIRC (POS) COG P1336 Ð Ð X EC-517
EVAP VERY SMALL LEAK P1441 X X X*2 EC-526
PURG VOLUME CONT/V P1444 Ð Ð X EC-541
VENT CONTROL VALVE P1446 Ð Ð X EC-553
EVAP PURG FLOW/MON P1447 X X X*2 EC-561
VENT CONTROL VALVE P1448 Ð Ð X EC-573
FUEL LEVEL SEN/CIRC P1464 Ð Ð X EC-582
VC/V BYPASS/V P1490 Ð Ð X EC-585
VC CUT/V BYPASS/V P1491 Ð Ð X EC-591
A/T DIAG COMM LINE P1605 Ð Ð X EC-603
TP SEN/CIRC A/T P1705 Ð Ð X AT-218
P-N POS SW/CIRCUIT P1706 Ð Ð X EC-604
O/R CLTCH SOL/CIRC P1760 Ð Ð X AT-223
*1: 1st trip DTC No. is the same as DTC No.
*2: These are not displayed with GST.
NOTE:
Regarding R50 models, ª-B1º and ªBK1º indicate right bank and ª-B2º and ªBK2º indicate left bank.
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATIONNBEC0031S06How to Erase DTC (With CONSULT-II)NBEC0031S0601NOTE:
If the DTC is not for A/T related items (see EC-8), skip steps 2 through 4.
1. If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
10 seconds and then turn it ªONº (engine stopped) again.
2. Turn CONSULT-II ªONº and touch ªA/Tº.
3. Touch ªSELF-DIAG RESULTSº.
4. Touch ªERASEº. [The DTC in the TCM (Transmission control module) will be erased.] Then touch ªBACKº
twice.
5. Touch ªENGINEº.
6. Touch ªSELF-DIAG RESULTSº.
7. Touch ªERASEº. (The DTC in the ECM will be erased.)
IIf DTCs are displayed for both ECM and TCM (Transmission control module), they need to be erased
individually from the ECM and TCM (Transmission control module).
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Emission-related Diagnostic Information (Cont'd)
EC-72

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)
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-75

ENGINE CONTROL COMPONENT PARTS/CONTROL
SYSTEMS APPLICATION
NBEC0034S02
ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOSTIC
RESULTS
D ATA
MONI-
TORD ATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*1FREEZE
FRAME
DATA*2SRT
STATUSDTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor
(POS)XXXX
Crankshaft position sensor (REF) X X X
Mass air flow sensor X X X
Engine coolant temperature sen-
sorXXXXX
Heated oxygen sensor 1 (front) X X X X X
Heated oxygen sensor 2 (rear) X X X X X
Vehicle speed sensorXXXX
Throttle position sensor X X X
Fuel tank temperature sensor X X X X
EVAP control system pressure
sensorXXX
Absolute pressure sensor X X X
Intake air temperature sensor X X X
Knock sensor X
Ignition switch (start signal) X X
Closed throttle position switch X X X
Closed throttle position switch
(throttle position sensor signal)XX
Air conditioner switch X X
Park/neutral position (PNP)
switchXXX
Power steering oil pressure
switchXX
Battery voltage X X
Ambient air temperature switch X X
Load signal X X
Swirl control valve control
vacuum check switchXXX
Fuel level sensor X X X
Intake valve timing control posi-
tion sensorXXX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-82

ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOSTIC
RESULTS
D ATA
MONI-
TORD ATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*1FREEZE
FRAME
DATA*2SRT
STATUSDTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Injectors X X X
Power transistor (Ignition timing)X
(Ignition
signal)XXX
IACV-AAC valve X X X X
EVAP canister purge volume
control solenoid valveX XXX X
Air conditioner relay X X
Fuel pump relay X X X X
Heated oxygen sensor 1 (front)
heaterXXXX
Heated oxygen sensor 2 (rear)
heaterXXXX
EVAP canister vent control valve X X X X
Vacuum cut valve bypass valve X X X X X
Swirl control valve control sole-
noid valveX XXX
VIAS control solenoid valve X X X
Intake valve timing control sole-
noid valveX XXX
Calculated load value X X X
X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-II screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-60.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-83

WORK SUPPORT MODE=NBEC0034S04
WORK ITEM CONDITION USAGE
TP SW/TP SEN IDLE POSI ADJIFOLLOW THE BASIC INSPECTION INSTRUCTION IN
THE SERVICE MANUAL.When adjusting the idle throttle
position
FUEL PRESSURE RELEASEIFUEL PUMP WILL STOP BY TOUCHING ªSTARTº
DURING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.When releasing fuel pressure
from fuel line
IDLE AIR VOL LEARNITHE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM.When learning the idle air volume
SELF-LEARNING CONTITHE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL
COEFFICIENT.When clearing the coefficient of
self-learning control valve
EVAP SYSTEM CLOSE OPEN THE VACUUM CUT VALVE BYPASS VALVE AND
CLOSE THE EVAP CANISTER VENT CONTROL VALVE
IN ORDER TO MAKE EVAP SYSTEM CLOSE UNDER
THE FOLLOWING CONDITIONS.
IIGN SW ªONº
IENGINE NOT RUNNING
IAMBIENT TEMPERATURE IS ABOVE 0ÉC (32ÉF).
INO VACUUM AND NO HIGH PRESSURE IN EVAP
SYSTEM
ITANK FUEL TEMP. IS MORE THAN 0ÉC (32ÉF).
IWITHIN 10 MINUTES AFTER STARTING ªEVAP SYS-
TEM CLOSEº
IWHEN TRYING TO EXECUTE ªEVAP SYSTEM
CLOSEº UNDER THE CONDITION EXCEPT ABOVE,
CONSULT-II WILL DISCONTINUE IT AND DISPLAY
APPROPRIATE INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-II MAY DIS-
PLAY ªBATTERY VOLTAGE IS LOW. CHARGE
BATTERYº, EVEN IN USING CHARGED BATTERY.When detecting EVAP vapor leak
point of EVAP system
TARGET IGNITION TIMING ADJ*IIDLE CONDITIONIWhen adjusting target ignition
timing
After adjustment, confirm target
ignition timing with a timing
light.
IIf once the ªTARGET IDLE
RPM ADJº has been done, the
Idle Air Volume Learning proce-
dure will not be completed.
TARGET IDLE RPM ADJ*IIDLE CONDITION When setting target idle speed
*: This function is not necessary in the usual service procedure.
SELF-DIAGNOSTIC MODENBEC0034S05DTC and 1st Trip DTCNBEC0034S0501Regarding items of ªDTC and 1st trip DTCº, refer to ªTROUBLE
DIAGNOSIS Ð INDEXº (See EC-8.)
Freeze Frame Data and 1st Trip Freeze Frame DataNBEC0034S0502
Freeze frame data
item*1Description
DIAG TROUBLE
CODE
[PXXXX]IThe engine control component part/control system has a trouble code, it is displayed as ªPXXXXº.
(Refer to ªTROUBLE DIAGNOSIS Ð INDEXº, EC-8.)
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-85