2007 INFINITI QX56 coolant

TROUBLE DIAGNOSIS
EC-115
< SERVICE INFORMATION >
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*: The item is the same as that of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×: Applicable
B/FUEL SCHDL
[msec]• The base fuel schedule at the moment a malfunction is detected is displayed.
INT/A TEMP SE
[°C] or [°F]• The intake air temperature at the moment a malfunction is detected is displayed. Freeze frame data
item*Description
Monitored item
[Unit]ECM IN-
PUT SIG-
NALSMAIN
SIGNALSDescription 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.
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.
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.
• This data also includes the data for the
air-fuel ratio learning control. A/F ALPHA-B2 [%]×
COOLAN TEMP/S
[°C] or [°F]×ו 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 internally. Thus, it differs from
ECM terminal voltage signal. ACCEL SEN 2 [V]×
THRTL SEN 1 [V]××
• The throttle position sensor signal volt-
age is displayed.• THRTL SEN 2 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal. THRTL SEN 2 [V]×

EC-120
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-49, "Emission-related Diagnostic Information".
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION• Engine: Return to the original
trouble condition
• Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.• Harness and connectors
• Fuel injector
• Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING• Engine: Return to the original
trouble condition
• Timing light: Set
• Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.• Perform Idle Air Volume Learning.
POWER BAL-
ANCE• Engine: After warming up, idle the
engine.
• A/C switch: OFF
• Selector lever: P or N
• Cut off each injector signal one at
a time using CONSULT-II.Engine runs rough or dies.• Harness and connectors
• Compression
• Fuel injector
• Power transistor
•Spark plug
• Ignition coil
COOLING FAN*• Ignition switch: ON
• Turn the cooling fan HI and OFF
using CONSULT-II.Cooling fan moves and stops.• Harness and connectors
• Cooling fan motor
• IPDM E/R
ENG COOLANT
TEMP• Engine: Return to the original
trouble condition
• Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.• Harness and connectors
• Engine coolant temperature sen-
sor
• Fuel injector
FUEL PUMP RE-
LAY• Ignition switch: ON
(Engine stopped)
• Turn the fuel pump relay ON and
OFF using CONSULT-II and lis-
ten to operating sound.Fuel pump relay makes the operat-
ing sound.• Harness and connectors
•Fuel pump relay
PURG VOL
CONT/V• Engine: After warming up, run en-
gine at 1,500 rpm.
• Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.Engine speed changes according to
the opening percent.• Harness and connectors
• Solenoid valve
FUEL/T TEMP
SEN• Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V• Ignition switch: ON
(Engine stopped)
• Turn solenoid valve ON and OFF
with the CONSULT-II and listen to
operating sound.Solenoid valve makes an operating
sound.• Harness and connectors
• Solenoid valve
V/T ASSIGN AN-
GLE• Engine: Return to the original
trouble condition
• Change intake valve timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.• Harness and connectors
• Intake valve timing control sole-
noid valve
ALTERNATOR
DUTY•Engine: Idle
• Change duty ratio using CON-
SULT-II.Battery voltage changes.• Harness and connectors
• IPDM E/R
•Alternator

EC-126
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
COOLING FAN• Engine: After warming up, idle the
engine
• Air conditioner switch: OFFEngine coolant temperature: 99°C
(210°F) or lessOFF
Engine coolant temperature: 100°C
(212°F) or moreHI
HO2S2 HTR (B1)
HO2S2 HTR (B2)• Engine speed: Below 3,600 rpm after the following conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no loadON
• Engine speed: Above 3,600 rpm OFF
I/P PULLY SPD • Vehicle speed: More than 20 km/h (12 MPH)Almost the same speed as the
tachometer indication
VEHICLE SPEED• Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
TRVL AFTER MIL • Ignition switch: ONVehicle has traveled after MIL has
turned ON.0 - 65,535 km
(0 - 40,723 mile)
A/F S1 HTR (B1)
A/F S1 HTR (B2)• Engine: After warming up, idle the engine 4 - 100%
AC PRESS SEN• Engine: Idle
• Both A/C switch and blower fan switch: ON (Compressor operates.)1.0 - 4.0V
VHCL SPEED SE• Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
SET VHCL SPD • Engine: Running ASCD: Operating.The preset vehicle speed is dis-
played.
MAIN SW • Ignition switch: ONMAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW • Ignition switch: ONCANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW • Ignition switch: ONRESUME/ACCELERATE switch:
PressedON
RESUME/ACCELERATE switch: Re-
leasedOFF
SET SW • Ignition switch: ONSET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DIST SW • Ignition switch: ONDISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
BRAKE SW1 • Ignition switch: ONBrake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2 • Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP • Ignition switch: ONMAIN switch: Pressed at the 1st time
→ at the 2nd timeON → OFF
SET LAMP• MAIN switch: ON
• Vehicle speed: Between 40 km/h
(25 MPH) and 144 km/h (89
MPH)ASCD: Operating ON
ASCD: Not operating OFF
ALT DUTY • Engine: Idle 0 - 80%
BAT CUR SEN• Engine speed: Idle
• Battery: Fully charged*
2
• Selector lever: P or N
• Air conditioner switch: OFF
•No loadApprox. 2,600 - 3,500mV MONITOR ITEM CONDITION SPECIFICATION

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-129
< SERVICE INFORMATION >
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TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000003531630
The specification (SP) value indicates the tolerance of the value that is displayed in “DATA MONITOR (SPEC)”
mode of CONSULT-II during normal operation of the Engine Control System. When the value in “DATA MONI-
TOR (SPEC)” mode is within the SP value, the Engine Control System is confirmed OK. When the value in
“DATA MONITOR (SPEC)” mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
• B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board correc-
tion)
• A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
• MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionINFOID:0000000003531631
• Vehicle driven distance: More than 5,000 km (3,107 miles)
• Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm
2 , 14.25 - 15.12 psi)
• Atmospheric temperature: 20 - 30°C (68 - 86°F)
• Engine coolant temperature: 75 - 95°C (167 - 203°F)
• Engine speed: Idle
• Transmission: Warmed-up
- After the engine is warmed up to normal operating temperature, drive vehicle until “ATF TEMP SE 1” (A/T
fluid temperature sensor signal) indicates more than 60°C (140°F).
• Electrical load: Not applied
- Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureINFOID:0000000003531632
NOTE:
Perform “DATA MONITOR (SPEC)” mode in maximum scale display.
1. Perform EC-71, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2”
and “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode with
CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-130, "
Diagnosis Procedure" .
SEF601Z

DTC P0011, P0021 IVT CONTROL
EC-149
< SERVICE INFORMATION >
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DTC P0011, P0021 IVT CONTROL
DescriptionINFOID:0000000003531648
SYSTEM DESCRIPTION
*: This signal is sent to the ECM through CAN communication line
This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing (IVT) control sole-
noid valve depending on driving status. This makes it possible to control the shut/open timing of the intake
valve to increase engine torque in low/mid speed range and output in high-speed range.
COMPONENT DESCRIPTION
Intake Valve Timing Control Solenoid Valve
Intake Valve Timing (IVT) control solenoid valve is activated by ON/
OFF pulse duty (ratio) signals from the ECM.
The IVT control solenoid valve changes the oil amount and direction
of flow through intake valve timing control unit or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.
Intake Valve Timing Control Position Sensor
Sensor Input signal to ECM function ECM Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
Intake valve
timing controlIntake valve timing control
solenoid valve Intake valve timing control position sensor Intake valve timing signal
Engine coolant temperature sensor Engine coolant temperature
Wheel sensor Vehicle speed*
PBIB3276E
PBIB1842E

EC-170
< SERVICE INFORMATION >
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DescriptionINFOID:0000000003531664
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531665
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531666
DTC Confirmation ProcedureINFOID:0000000003531667
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600OFF
Below 3,600 rpm after the following conditions are met.
• Engine: After warming up
• Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no loadON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)• Engine speed: Below 3,600 rpm after the following conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no loadON
• Engine speed: Above 3,600 rpm OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0037
0037
(Bank 1)
Heated oxygen sensor 2
heater control circuit lowThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)• Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
• Heated oxygen sensor 2 heater P0057
0057
(Bank 2)
P0038
0038
(Bank 1)
Heated oxygen sensor 2
heater control circuit highThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)• Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
• Heated oxygen sensor 2 heater P0058
0058
(Bank 2)

DTC P0117, P0118 ECT SENSOR
EC-205
< SERVICE INFORMATION >
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DTC P0117, P0118 ECT SENSOR
Component DescriptionINFOID:0000000003531704
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000003531705
These self-diagnoses have the one trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
SEF594K
Engine coolant temperature
°C (°F)Voltage* V Resistance kΩ
–10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC
No.Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P0117
0117Engine coolant temperature
sensor circuit low inputAn excessively low voltage from the sensor is
sent to ECM.• Harness or connectors
(The sensor circuit is open or shorted.)
• Engine coolant temperature sensor P0118
0118Engine coolant temperature
sensor circuit high inputAn excessively high voltage from the sensor is
sent to ECM.

EC-206
< SERVICE INFORMATION >
DTC P0117, P0118 ECT SENSOR
DTC Confirmation Procedure
INFOID:0000000003531706
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If DTC is detected, go to EC-207, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Detected items Engine operating condition in fail-safe mode
Engine coolant temper-
ature sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning ignition switch ON
or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned ON or START 40°C (104°F)
More than approx. 4 minutes after ignition ON or
START80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates while
engine is running.
SEF058Y