DLN-98
< DTC/CIRCUIT DIAGNOSIS >[TRANSFER: ATX90A]
4WD INDICATOR LAMP
4WD INDICATOR LAMP
Component Function CheckINFOID:0000000006222310
1.CHECK 4WD MODE INDICATOR LAMP FUNCTION
1. Start the engine CAUTION:
Never drive the vehicle.
2. Turn the 4WD shift switch AUTO ⇒4H ⇒4LO ⇒4H ⇒AUTO.
3. Check the 4WD shift switch position (“AUTO”, “4H” and “4L”) and the indication of the 4WD mode indica-
tor lamp mutually coincide.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to diagnosis procedure. Refer to DLN-98, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006222311
1.CHECK POWER SUPPLY AND GROUND CIRCUIT
Perform the trouble diagnosis for power supply and ground circuit. Refer to DLN-64, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace the error-detected parts.
2.CHECK 4WD WARNING LAMP SIGNAL
With CONSULT-III
1. Strat the engine.
CAUTION:
Never drive the vehicle.
2. Turn the 4WD shift switch AUTO ⇒4H ⇒4LO ⇒4H ⇒AUTO.
3. Check “4WD MODE IND” of CONSULT-III “DATA MONITOR” for “ALL MODE AWD/4WD”.
Is the inspection result normal?
YES >> Check combination meter. Refer to MWI-64, "COMBINATION METER : Diagnosis Procedure".
NO >> Replace transfer control unit. Refer to DLN-107, "
Removal and Installation".
Monitor item Condition Status
4WD MODE IND 4WD shift switch: AUTO AUTO
4WD shift switch: 4H 4H
4WD shift switch: 4L 4L
Revision: 2010 May2011 QX56
COMPONENT PARTSEC-21
< SYSTEM DESCRIPTION > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Accelerator Pedal
Position SensorINFOID:0000000006217658
The accelerator pedal position (APP) sensor is installed on the
accelerator pedal assembly. The sensor detects the accelerator
position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometer which transform the accelerator pedal
position into output voltage, and emit the voltage signals to the ECM.
The ECM judges the current opening angle of the accelerator pedal
from these signals and controls the throttle control motor based on
these signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The
ECM uses this signal for engine operations such as fuel cut.
Air Fuel Ratio (A/F) Sensor 1INFOID:0000000006217659
DESCRIPTION
The sensor element of the A/F sensor 1 is composed an electrode layer, which transports ions. It has a heater
in the element.
The sensor is capable of precise measurement = 1, but also in the lean and rich range. Together with its
control electronics, the sens or outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at the sensor cell. An electrode layer is
applied voltage, and this current relative oxygen density in lean. Also this current relative hydrocarbon density
in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of approxi-
mately 760 °C (1,400 °F).
A/F SENSOR 1 HEATER
A/F sensor 1 heater is integrated in the sensor.
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F s ensor 1 element within the specified range.
ASCD Brake Switch & Stop Lamp Switch INFOID:0000000006217660
Stop lamp switch and ASCD brake switch are installed to brake pedal bracket.
When the brake pedal is depressed, ASCD brake switch is turned OFF and stop lamp switch is turned ON.
ECM detects the state of the brake pedal by those two types of input (ON/OFF signal).
ASCD Steering SwitchINFOID:0000000006217661
ASCD steering switch has variant values of electrical resistance for each button. ECM reads voltage variation
of switch, and determines which button is operated.
ASCD IndicatorsINFOID:0000000006217662
ASCD operation status is indicated by CRUISE indicator in combination meter.
ECM transmits the ASCD status signal to the combi nation meter via CAN communication according to ASCD
operation.
PBIB1741E
JSBIA0527GB
Revision: 2010 May2011 QX56
COMPONENT PARTSEC-23
< SYSTEM DESCRIPTION > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
ECM receives the signals as shown in the figure.
Crankshaft Position SensorINFOID:0000000006217665
The crankshaft position (CKP) sensor senses the protrusion of the
signal plate installed to the drive plate to identify fluctuation of the
engine revolution.
The sensor consists of a permanent magnet and Hall IC.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic fiel
d, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM receives the signals as shown in the figure.
ECMINFOID:0000000006217666
ECM (Engine Control Module) controls the engine.
The ECM consists of a microcomputer and connectors for trans- mitting/receiving signals and for supplying power. Furthermore, the
ECM is equipped with an injector dr iver unit and actuates the fuel
injector at a high voltage (approximately 70 V at the maximum).
ECM is equipped with ECM temperature sensors. If ECM is over- heated, ECM controls output torque to prevent damage to itself.
Battery voltage is supplied to the ECM even when the ignition
switch is turned OFF for the ECM memory function of the DTC
memory, the air-fuel ratio feedback compensation value memory,
the idle air volume learning value memory, etc.
Electric Throttle Control ActuatorINFOID:0000000006217667
OUTLINE
JMBIA1559GB
JMBIA0062ZZ
JMBIA1559GB
JMBIA0057ZZ
Revision: 2010 May2011 QX56
COMPONENT PARTSEC-25
< SYSTEM DESCRIPTION > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
OEngine Coolant Temperature SensorINFOID:0000000006217669
The engine coolant temperature (ECT
) 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 sens or uses a thermistor which is
sensitive to the change in temperature. The electrical resistance of
the thermistor decreases as temperature increases.
*: These data are reference values and are measured between ECM terminals.
Engine Oil Temperature SensorINFOID:0000000006217670
The engine oil temperature sensor is used to detect the engine oil
temperature. The sensor modifies a voltage signal from the ECM.
The modified signal returns to the ECM as the engine oil tempera-
ture input. The sensor uses a ther mistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.
*: These data are reference values and are measured between ECM terminals. 1. Valve 2. Armature 3. Magnet Loop Element
4. Fan speed sensor 5. Coil 6. Silicon oil
SEF594K
Engine coolant temperature
[° C ( °F)] Voltage* (V) Resistance (k
Ω)
− 10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.35 - 2.73
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
SEF594K
Engine oil temperature [° C ( °F)] Voltage* (V) Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.35 - 2.73
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
110 (230) 0.6 0.143 - 0.153
SEF012P
Revision: 2010 May2011 QX56
COMPONENT PARTSEC-27
< SYSTEM DESCRIPTION > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
The sensor detects a fuel level in the fuel tank and tr
ansmits a signal to the combination meter. The combina-
tion meter sends the fuel level sensor signal to the ECM via the CAN communication line.
It consists of two parts, one is mechanical float and the ot her is variable resistor. Fuel level sensor output volt-
age changes depending on the movement of the fuel mechanical float.
Fuel Pump Control ModuleINFOID:0000000006217674
The fuel pump control module (FPCM) controls the discharging vol-
ume of the fuel pump by transmitt ing the FPCM control signals (Low/
Mid/High) depending on driving conditions.
Fuel Rail Pressure SensorINFOID:0000000006217675
The fuel rail pressure (FRP) sensor is placed to the fuel rail and
measures fuel pressure in the fuel rail. The sensor transmits voltage
signal to the ECM. As the pressure increases, the voltage rises. The
ECM controls the fuel pressure in the fuel rail by operating high pres-
sure fuel pump. The ECM uses the signal from fuel rail pressure sen-
sor as a feedback signal.
Fuel Tank Temperature SensorINFOID:0000000006217676
The fuel tank temperature sensor is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a ther mistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.
*: These data are reference values and are measured between ECM terminals.
Heated Oxygen Sensor 2INFOID:0000000006217677
DESCRIPTION
NNBIB0006ZZ
JSBIA0291ZZ
Fuel temperature [ °C ( °F)] Voltage* (V) Resistance (k Ω)
20 (68) 3.5 2.3 - 2.7
50 (122) 2.2 0.79 - 0.90
SEF012P
Revision: 2010 May2011 QX56
COMPONENT PARTSEC-29
< SYSTEM DESCRIPTION > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Operating Chart
ICC Brake Switch & Stop Lamp SwitchINFOID:0000000006217679
Stop lamp switch and ICC brake switch are installed to brake pedal bracket.
When the brake pedal is depressed, I
CC brake switch is turned OFF and stop lamp switch is turned ON.
ECM detects the state of the brake pedal by those two types of input (ON/OFF signal).
ECM transmits ICC brake switch signal to ADAS control unit via CAN communication line.
ICC Steering SwitchINFOID:0000000006217680
ICC steering switch has variant values of electrical resistance for each button. ECM reads voltage variation of
switch, and determines which button is operated.
ECM transmits ICC steering switch signal to ADAS control unit via CAN communication line.
Ignition Coil With Power TransistorINFOID:0000000006217681
The ignition signal from the ECM is sent to and amplified by the
power transistor. The power transistor turns ON and OFF the ignition
coil primary circuit. This ON/OFF operation induces the proper high
voltage in the coil secondary circuit.
Intake Valve Timing Control Solenoid ValveINFOID:0000000006217682
Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing 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.
JSBIA0286GB
PBID0206J
PBIB1842E
Revision: 2010 May2011 QX56
EC-30
< SYSTEM DESCRIPTION >[VK56VD]
COMPONENT PARTS
Knock Sensor
INFOID:0000000006217683
The knock sensor is attached to t he cylinder block. It senses engine
knocking using a piezoelectric element. A knocking vibration from
the cylinder block is sensed as vibrational pressure. This pressure is
converted into a voltage signal and sent to the ECM.
Low Fuel Pressure SensorINFOID:0000000006217684
The low fuel pressure sensor is installed to low fuel pressure piping
and measures the low fuel pressu re. The sensor transmits voltage
signal to the ECM. As the pressure increases, the voltage rises.
Low Pressure Fuel PumpINFOID:0000000006217685
The low pressure fuel pump is integrated with a fuel pressure regula-
tor and a fuel filter. This pump is build into the fuel tank.
ECM controls the low pressure fuel pump via FPCM.
Malfunction Indicator Lamp (MIL)INFOID:0000000006217686
The Malfunction Indicator Lamp (MIL) is located on the combination
meter.
The MIL will illuminate when the ignition switch is turned ON without
the engine running. This is a bulb check.
When the engine is started, the MIL should turn off. If the MIL
remains illuminated, the on board diagnostic system has detected an
engine system malfunction.
For details, refer to EC-51, "
Diagnosis Description".
JSBIA0284ZZ
JSBIA0292ZZ
JPBIA3235ZZ
SEF217U
Revision: 2010 May2011 QX56
EC-40
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
SYSTEM DESCRIPTION
Low fuel pressure control
The low fuel pressure pump is controlled by the f
uel pump control module (FPCM) and pumps fuel according
to a driving condition. The pumped fuel passes through t he fuel filter and is sent to the high pressure fuel
pump. FPCM controls the low pressure fuel pump, ac cording to a signal from ECM as shown in the table
below.
Low fuel pressure is adjusted by the fuel pressure regulator.
High fuel pressure control
The high pressure fuel pump raises the pressure of the fuel sent from the low pressure fuel pump. Actuated
by the camshaft, the high pressure fuel pump activates the high pressure fuel pump solenoid based on a sig-
nal received from ECM, and adjusts the amount of di scharge by changing the timing of closing the inlet
check valve to control fuel rail pressure.
COOLING FAN CONTROL
JSBIA0235GB
Conditions Amount of fuel flow Supplied voltage
After a laps of 1 second after ignition ON OFF 0 V
For 1 second after turning ignition switch ON
Engine is running under low load and low speed conditions Low Approximately 8.5 V
Engine cranking
Engine coolant temperature is below 10 °C (50 °F)
Engine is running under high load and high speed conditions High
Battery voltage
(11 – 14 V)
Except the above Mid Approximately 10 V
Revision: 2010 May2011 QX56