2008 INFINITI QX56 Fuel sensor

EC-50
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
HO2S05H
Air fuel ratio (A/F) sensor 1
(Bank 2) P0151 83H 0BH
Minimum sensor output voltage
for test cycle
P0151 84H 0BH Maximum sensor output voltage
for test cycle
P0150 85H 0BH Minimum sensor output voltage
for test cycle
P0150 86H 0BH Maximum sensor output voltage
for test cycle
P0153 87H 04H Response rate: Response ratio
(Lean to Rich)
P0153 88H 04H Response rate: Response ratio
(Rich to Lean)
P2A03 89H 84H The amount of shift in air fuel ratio
P2A03 8AH 84H The amount of shift in air fuel ratio
P0150 8BH 0BH Difference in sensor output volt-
age
P0153 8CH 83H Response gain at the limited fre-
quency
06H Heated oxygen sensor 2
(Bank 2) P0158 07H 0CH
Minimum sensor output voltage
for test cycle
P0157 08H 0CH Maximum sensor output voltage
for test cycle
P0158 80H 0CH Sensor output voltage
P0159 81H 0CH Difference in sensor output volt-
age
07H Heated oxygen sensor 3
(Bank2) P0163 07H 0CH
Minimum sensor output voltage
for test cycle
P0164 08H 0CH Maximum sensor output voltage
for test cycle
P0166 80H 0CH Sensor output voltage
P0165 81H 0CH Difference in sensor output volt-
age
CATA-
LY S T 21H
Three way catalyst function
(Bank1) P0420 80H 01H O2 storage index
P0420 82H 01H
Switching time lag engine exhaust
index value
P2423 83H 0CH Difference in 3rd O2 sensor out-
put voltage
P2423 84H 84H O2 storage index in HC trap cata-
lyst
22H Three way catalyst function
(Bank2) P0430 80H 01H O2 storage index
P0430 82H 01H
Switching time lag engine exhaust
index value
P2424 83H 0CH Difference in 3rd O2 sensor out-
put voltage
P2424 84H 84H O2 storage index in HC trap cata-
lyst
Item
OBD-
MID Self-diagnostic test item
DTCTest value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: March 2010 2008 QX56

EC-56
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
When there is an open circuit on MIL circuit, the ECM c
annot warn the driver by lighting up MIL when there is
malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine cont rol system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnos es except MIL circuit are detected and demands the
driver to repair the malfunction.
MIL Flashing Without DTC
When any SRT codes are not set, MIL may fl ash without DTC. For the details, refer to EC-462, "DTC Index".
HOW TO SWITCH DIAGNOSTIC TEST MODE
NOTE:
•It is better to count the ti me accurately with a clock.
• It is impossible to switch the di agnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
• Always ECM returns to Diagnostic Test Mode I after ignition switch is turned OFF.
How to Set Diagnostic Test Mode II (Self-diagnostic Results)
1. Confirm that accelerator pedal is fully releas ed, turn ignition switch ON and wait 3 seconds.
2. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the MIL starts blinking.
NOTE:
Do not release the accelerator pedal for 10 seconds if MIL may start blinking on the halfway of this
10 seconds. This blinking is displaying SRT status and is continued for another 10 seconds. For
the details, refer to EC-462, "
DTC Index".
Diagnostic Test
ModeKEY and ENG.
Status Function
Explanation of Function
Mode I Ignition switch in
ON 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 WARNING This is a usual driving condition. When a malfunction is de-
tected twice in two consecutive driving cycles (two trip de-
tection 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.
• Misfire (Possible three way catalyst damage)
• One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stopped SELF-DIAGNOSTIC
RESULTS
This function allows DTCs an
d 1st trip DTCs to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
Revision: March 2010 2008 QX56

EC-64
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ItemDIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI-
TOR ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS) ×××
Camshaft position sensor (PHASE) ×××
Mass air flow sensor ××
Engine coolant temperature sensor ××××
Air fuel ratio (A/F) sensor 1 ××× ×
Heated oxygen sensor 2 ××× ×
Wheel sensor ×××
Accelerator pedal position sensor ××
Throttle position sensor ×××
Fuel tank temperature sensor ×××
EVAP control system pressure sen-
sor ××
Intake air temperature sensor ×××
Knock sensor ×
Refrigerant pressure sensor ×
Closed throttle position switch (ac-
celerator pedal position sensor sig-
nal) ×
Air conditioner switch ×
Park/neutral position (PNP) signal ××
Stop lamp switch ××
Power steering pressure sensor ××
Battery voltage ×
Load signal ×
Intake valve timing control position
sensor ××
Fuel level sensor ××
Battery current sensor ××
ICC steering switch ××
ASCD steering switch ××
ICC brake switch ××
ASCD brake switch ××
Revision: March 2010 2008 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-65
< FUNCTION DIAGNOSIS > [VK56DE]
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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-III screen in freeze frame
data
mode only if a 1st trip DTC or DTC is detected. For details, refer to "Freeze Frame Data and 1st Trip Freeze Frame Data".
*3: Always “CMPLT ” is displayed.
WORK SUPPORT MODE
Work Item
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Fuel injector ××
Power transistor (Ignition timing) ××
Throttle contro l motor relay ××
Throttle control motor ×
EVAP canister purge volume con-
trol solenoid valve ××
××
Air conditioner relay ×
Fuel pump relay ×× ×
Cooling fan relay ×××
Air fuel ratio (A/F) sensor 1 heater ×××*3
Heated oxygen sensor 2 heater ×××*3
EVAP canister vent control valve ×× ××
Intake valve timing control solenoid
valve ××
×
Alternator ××
Calculated load value ××
Item
DIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI- TOR ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK SUP-
PORT
WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASE • FUEL PUMP WILL STOP BY TOUCHING “START” DUR- ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS. When releasing fuel pressure from
fuel line
IDLE AIR VOL LEARN • THE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM. When learning the idle air volume
SELF-LEARNING CONT • THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing the coefficient of
self-learning control value
Revision: March 2010
2008 QX56

EC-66
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: This function is not necessary in the usual service procedure.
SELF-DIAG RESULTS MODE
Self Diagnostic Item
Regarding items of DTC and 1st trip DTC, refer to
EC-462, "DTC Index".
Freeze Frame Data and 1st Trip Freeze Frame Data
EVAP SYSTEM CLOSECLOSE THE EVAP CANISTER VENT CONTROL VALVE IN
ORDER TO MAKE EVAP SYSTEM CLOSE UNDER THE
FOLLOWING CONDITIONS.
• IGN SW ON
• ENGINE NOT RUNNING
• AMBIENT TEMPERATURE IS ABOVE 0° C (32°F).
• NO VACUUM AND NO HIGH PRESSURE IN EVAP SYS- TEM
• FUEL TANK TEMP. IS MORE THAN 0 °C (32 °F).
• WITHIN 10 MINUTES AFTER STARTING “EVAP SYS- TEM CLOSE”
• WHEN TRYING TO EXECUTE “EVAP SYSTEM CLOSE” UNDER THE CONDITION EXCEPT ABOVE, CONSULT-
III WILL DISCONTINUE IT AND DISPLAY APPROPRI-
ATE INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-III MAY DIS-
PLAY “BATTERY VOLTAGE IS LOW. CHARGE BAT-
TERY”, EVEN IN USING CHARGED BATTERY. When detecting EVAP vapor leak
point of EVAP system
VIN REGISTRATION • IN THIS MODE, VIN IS REGISTERED IN ECMWhen registering VIN in ECM
TARGET IDLE RPM ADJ* • IDLE CONDITION When setting target idle speed
TARGET IGN TIM ADJ* • IDLE CONDITION When adjusting target ignition tim-
ing
WORK ITEM
CONDITION USAGE
Freeze frame data
item* Description
DIAG TROUBLE
CODE
[PXXXX] • The engine control co
mponent part/control system has a trouble code, it is displayed as PXXX X. (Refer to
EC-462, "
DTC Index".)
FUEL SYS-B1 • “Fuel injection system status” at the moment a malfunction is detected is displayed.
• One mode in the following is displayed. Mode2: Open loop due to detected system malfunction
Mode3: Open loop due to driving conditions (power enrichment, deceleration enleanment)
Mode4: Closed loop - using oxygen sensor(s) as feedback for fuel control
Mode5: Open loop - has not yet satisfied condition to go to closed loop
FUEL SYS-B2
CAL/LD VALUE [%] • The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP
[
° C] or [ °F] • The engine coolant temperature at the moment a malfunction is detected is displayed.
L-FUEL TRM-B1 [%] • “Long-term fuel trim” at the moment a malfunction is detected is displayed. • The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule than short-term fuel trim.
L-FUEL TRM-B2 [%]
S-FUEL TRM-B1 [%] • “Short-term fuel trim” at the
moment a malfunction is detected is displayed.
• The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel sched-
ule.
S-FUEL TRM-B2 [%]
ENGINE SPEED [rpm] • The engine speed at the moment a malfunction is detected is displayed.
VEHICL SPEED
[km/h] or [mph] • The vehicle speed at the moment a malfunction is detected is displayed.
ABSOL TH-P/S
[%] • The throttle valve opening at the moment a malfunction is detected is displayed.
B/FUEL SCHDL
[msec] • The base fuel schedule at the moment a malfunction is detected is displayed.
Revision: March 2010
2008 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-67
< FUNCTION DIAGNOSIS > [VK56DE]
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*: The item is the same as that of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×
: Applicable
INT/A TEMP SE
[° C] or [ °F] • The intake air temperature at the moment a malfunction is detected is displayed.
INT MANI PRES [kPa] These items are displayed but are not applicable to this model.
FTFMCH1 Freeze frame data
item* Description
Monitored item
[Unit] ECM IN-
PUT SIG- NALS MAIN
SIGNALS Description
Remarks
ENG SPEED [rpm] ×ו Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS) and camshaft position
sensor (PHASE). • Accuracy becomes poor if engine
speed drops below the idle rpm.
• If the signal is interrupted while the en- gine is running, an abnormal value may
be indicated.
MAS A/F SE-B1 [V] ×ו The signal voltage of the mass air flow
sensor is displayed. • When the engine is stopped, a certain
value is indicated.
• When engine is running specification
range is indicated in “SPEC”.
B/FUEL SCHDL
[msec] ו Base fuel schedule indicates the fuel in-
jection pulse width programmed into
ECM, prior to any learned on board cor-
rection. • When engine is running specification
range is indicated in “SPEC”.
A/F ALPHA-B1 [%] ×
• The mean value of the air-fuel ratio feed-back correction factor per cycle is indi-
cated. • When the engine is stopped, a certain
value is indicated.
• When engine is running specification
range is indicated in “SPEC”.
• This data also includes the data for the air-fuel ratio learning control.
A/F ALPHA-B2 [%]
×
COOLAN TEMP/S
[ ° C] or [ °F] ×× • The engine coolant temperature (deter-
mined by the signal voltage of the engine
coolant temperature sensor) is dis-
played. • When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine cool-
ant temperature determined by the
ECM is displayed.
A/F SEN1 (B1) [V] ××
• The A/F signal computed from the input
signal of the A/F sensor 1 is displayed.
A/F SEN1 (B2) [V] ×
HO2S2 (B1) [V] ×
• The signal voltage of the heated oxygen
sensor 2 is displayed.
HO2S2 (B2) [V] ×
HO2S2 MNTR (B1)
[RICH/LEAN] ו Display of heated oxygen sensor 2 sig-
nal:
RICH: means the amount of oxygen after
three way catalyst is relatively small.
LEAN: means the amount of oxygen af-
ter three way catalyst is relatively large. • When the engine is stopped, a certain
value is indicated.
HO2S2 MNTR (B2)
[RICH/LEAN] ×
VHCL SPEED SE
[km/h] or [mph] ×ו The vehicle speed computed from the
vehicle speed signal sent from combina-
tion meter is displayed.
BATTERY VOLT [V] ×ו The power supply voltage of ECM is dis-
played.
ACCEL SEN 1 [V] ××
• The accelerator pedal position sensor
signal voltage is displayed. • ACCEL SEN 2 signal is converted by
ECM
in

ternally. Thus, it differs from
ECM terminal voltage signal.
ACCEL SEN 2 [V]
×
Revision: March 2010 2008 QX56

EC-68
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
TP SEN 1-B1 [V]
××
• The throttle position sensor signal volt-
age is displayed. • TP SEN 2-B1 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal.
TP SEN 2-B1 [V]
×
FUEL T/TMP SE
[ ° C] or [ °F] × • The fuel temperature (determined by the
signal voltage of the fuel tank tempera-
ture sensor) is displayed.
INT/A TEMP SE
[ ° C] or [ °F] ×× • The intake air temperature (determined
by the signal voltage of the intake air
temperature sensor) is indicated.
EVAP SYS PRES
[V] ×
• The signal voltage of EVAP control sys-
tem pressure sensor is displayed.
FUEL LEVEL SE [V] ו The signal voltage of the fuel level sen-
sor is displayed.
START SIGNAL
[ON/OFF] ×ו Indicates start signal status [ON/OFF]
computed by the ECM according to the
signals of engine speed and battery volt-
age. • After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF] ×ו Indicates idle position [ON/OFF] comput-
ed by ECM according to the accelerator
pedal position sensor signal.
AIR COND SIG
[ON/OFF] ×ו Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF] ××
• Indicates [ON/OFF] condition from the
park/neutral position (PNP) signal.
PW/ST SIGNAL
[ON/OFF] ×ו [ON/OFF] condition of the power steering
system (determined by the signal voltage
of the power steering pressure sensor
signal) is indicated.
LOAD SIGNAL [ON/
OFF] ×ו Indicates [ON/OFF] condition from the
electrical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
IGNITION SW
[ON/OFF] ו Indicates [ON/OFF] condition from igni-
tion switch signal.
HEATER FAN SW
[ON/OFF] ×
• Indicates [ON/OFF] condition from heat-
er fan switch signal.
BRAKE SW
[ON/OFF] ו Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec] ×
• Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals. • When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING [BT-
DC] ו
Ind
ic
ates the ignition timing computed by
ECM according to the input signals. • When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE [%] • “Calculated load value” indicates the val-
ue of the current air flow divided by peak
air flow.
MASS AIRFLOW
[g·m/s] • Indicates the mass air flow computed by
ECM according to the signal voltage of
the mass air flow sensor.
Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description
Remarks
Revision: March 2010 2008 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-69
< FUNCTION DIAGNOSIS > [VK56DE]
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PURG VOL C/V [%]
• Indicates the EVAP canister purge vol-
ume control solenoid valve control value
computed by the ECM according to the
input signals.
• The opening becomes larger as the val- ue increases.
INT/V TIM (B1)
[ ° CA]
• Indicates [°CA] of intake camshaft ad-
vanced angle.
INT/V TIM (B2)
[ ° CA]
INT/V SOL (B1) [%] • The control value of the intake valve tim-
ing control solenoid valve (determined by
ECM according to the input signals) is in-
dicated.
• The advance angle becomes larger as
the value increases.
INT/V SOL (B2) [%]
AIR COND RLY
[ON/OFF]
ו The air conditioner relay control condi-
tion (determined by ECM according to
the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF] ו Indicates the fuel pump relay control con-
dition determined by ECM according to
the input signals.
VENT CONT/V
[ON/OFF] • The control condition of the EVAP canis-
ter vent control valve (determined by
ECM according to the input signals) is in-
dicated.
ON: Closed
OFF: Open
THRTL RELAY [ON/
OFF] ו Indicates the throttle control motor relay
control condition determined by the ECM
according to the input signals.
COOLING FAN
[HI/OFF] ו The control condition of the cooling fan
(determined by ECM according to the in-
put signals) is indicated.
HI: High speed operation
OFF: Stop
HO2S2 HTR (B1)
[ON/OFF] • Indicates [ON/OFF] condition of heated
oxygen sensor 2 heater determined by
ECM according to the input signals.
HO2S2 HTR (B2)
[ON/OFF]
I/P PULLY SPD
[rpm] ו Indicates the engine speed computed
from the input speed sensor signal.
VEHICLE SPEED
[km/h] or [mph] ו Indicates the vehicle speed computed
from the output speed sensor signal.
IDL A/V LEARN
[YET/CMPLT] • Display the condition of idle air volume
learning
YET: Idle Air Volume Learning has not
been performed yet.
CMPLT: Idle Air Volume Learning has al-
ready been performed successfully.
TRVL AFTER MIL
[km] or [mile] • Distance traveled while MIL is activated.
Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description
Remarks
Revision: March 2010 2008 QX56