relay INFINITI QX56 2008 Factory Service Manual

ECM
EC-437
< ECU DIAGNOSIS > [VK56DE]
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99 G/R
ASCD steering switch
(Models with ASCD system) [Ignition switch: ON]
• ASCD steering switch: OFF
Approximately 4V
[Ignition switch: ON]
• MAIN switch: Pressed Approximately 0V
[Ignition switch: ON]
• CANCEL switch: Pressed Approximately 1V
[Ignition switch: ON]
• RESUME/ACCELERATE switch: Pressed Approximately 3V
[Ignition switch: ON]
• SET/COAST switch: Pressed Approximately 2V
101 R/W Stop lamp switch [Ignition switch: OFF]
• Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
• Brake pedal: Slightly depressed BATTERY VOLTAGE
(11 - 14V)
102 GR/R PNP signal [Ignition switch: ON]
• Selector lever: P or N
Approximately 0V
[Ignition switch: ON]
• Except the above gear position BATTERY VOLTAGE
(11 - 14V)
104 O Throttle cont rol motor relay[Ignition switch: OFF]
BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON] 0 - 1.0V
106 BR/W Accelerator pedal position
sensor 1 [Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully depressed 4.2 - 4.8V
107 V/R Fuel tank temperature sensor [Engine is running]Approximately 0 - 4.8V
Output voltage varies with fuel
tank temperature.
108 BR/W ICC brake switch
(Models with ICC system)
ASCD brake switch
(Models with ASCD system) [Ignition switch: ON]
• Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
• Brake pedal: Fully released BATTERY VOLTAGE
(11 - 14V)
109 L/W Ignition switch [Ignition switch: OFF]
0V
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF 0 - 1.5V
[Ignition switch: OFF]
• More than a few seconds after turning igni- tion switch OFF BATTERY VOLTAGE
(11 - 14V)
11 3 G R F u e l p u m p r e l a y [Ignition switch: ON]
• For 1 second after turning ignition switch
ON
[Engine is running] 0 - 1.5V
[Ignition switch: ON]
• More than 1 second after turning ignition switch ON BATTERY VOLTAGE
(11 - 14V)
TER-
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NAL NO. WIRE
COLOR ITEM
CO
NDITION DA

TA (DC Voltage)
Revision: March 2010 2008 QX56

EC-460
< ECU DIAGNOSIS >[VK56DE]
ECM
• When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when there
is malfunction on engine control system.
Therefore, when electrical controlled throttle and pa rt of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engi ne control 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.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT-IIl displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-IIl display)
Just as ignition switch is turned ON
or START 40
°C (104 °F)
Approx 4 minutes or more after en-
gine starting. 80
°C (176 °F)
Except as shown above 40 - 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.
P0122
P0123
P0222
P0223
P2135 Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103 Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric throttle control function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric throttle control ac- tuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the
engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor
The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
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

HEADLAMPEXL-7
< FUNCTION DIAGNOSIS >
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FUNCTION DIAGNOSIS
HEADLAMP
System DiagramINFOID:0000000001547094
System DescriptionINFOID:0000000001547095
Control of the headlamp system operation is dependent upon the position of the lighting switch (combination
switch). When the lighting switch is placed in the 2nd position, the BCM (body control module) receives input
requesting the headlamps and park lamps to illuminate. Th is input is communicated to the IPDM E/R (intelli-
gent power distribution module engine room) via the CA N communication lines. The CPU (central processing
unit) of the IPDM E/R controls the headlamp high and headl amp low relay coils. When energized, these relays
direct power to the respective headlamps, which then illuminate.
Component Parts LocationINFOID:0000000001547096
Component DescriptionINFOID:0000000001547097
XENON HEADLAMP
A Xenon type headlamp is adapted to the low beam headlamps. Xenon bulbs do not use a filament.
Instead,they produce light when a high voltage current is passed between two tungsten electrodes through a
AWLIA0009GB
1. BCM M18, M20 (view with instrument
panel removed) 2. IPDM E/R E122, E123, E124 3. Combination switch M28
4. Combination meter M23, M24
ALLIA0379ZZ
Revision: March 2010 2008 QX56

EXL-8
< FUNCTION DIAGNOSIS >
HEADLAMP
mixtureof xenon (an inert gas) and certain other metal halides. In addition to added lighting power, electronic
controlof the power supply gives the headlamps stable quality and tone color.Following are some of the many
advantages of the xenon type headlamp.
• The light produced by the headlamps is a white color comparable to sunlight that is easy on the eyes.
• Light output is nearly double that of halogen headlamps, affording increased area of illumination.
• The light features a high relative spectral distribution at wavelengths to which the human eye is most sensi-tive. This means that even in the rain, more light is reflected back from the road surface toward the vehi-
cle,for added visibility.
• Power consumption is approximately 25 percent less than halogen headlamps, reducing battery load..
HIGH BEAM OPERATION/FLASH-TO-PASS OPERATION
With the lighting switch in the 2ND position and placed in HIGH position, the BCM receives input requesting
the headlamp high beams to illuminate. The flash to pass feature can be used any time and also sends a sig-
nal to the BCM. This input is communicated to t he IPDM E/R via the CAN communication lines. The CPU of
the combination meter controls the ON/OFF status off the HIGH BEAM indicator. The CPU of the IPDM E/R
controls the headlamp high relay coil which supplies power to the high beam headlamps.
The combination meter receives a high beam request signal (ON) via the CAN communication lines and turns
the high beam indicator lamp ON.
COMBINATION SWITCH READING FUNCTION
Refer to BCS-7, "System Description".
AUTO LIGHT OPERATION
Refer to EXL-11, "System Description".
Revision: March 2010 2008 QX56

EXL-10
< FUNCTION DIAGNOSIS >
DAYTIME LIGHT SYSTEM
Component Description
INFOID:0000000001547101
After starting the engine with the parking brake released and the lighting switch in the OFF or 1ST position, the
headlamp high beam automatically turns on at a reduced intensity. With the lighting switch in the 2nd position
or with autolamps ON, the headlamps function the same as conventional light systems.
OPERATION
The BCM monitors inputs from the parking brake switch and the combination switch to determine when to acti-
vate the daytime light system. The BCM sends a dayti me light request to the IPDM E/R via the CAN commu-
nication lines. The IPDM E/R grounds the daytime light relay which in turn, provides power to the ground side
of the LH high beam lamp. Power flows backward through the LH high beam lamp to the IPDM E/R, through
the high beam fuses, through the RH high beam lamp circuit to the RH high beam lamp and on to ground. The
high beam lamps are wired in series which causes them to illuminate at a reduced intensity.
1. IPDM E/R E119, E122, E123, E124 2. Parking brake switch M11 3. BCM M18, M20 (view with instrument
panel removed)
4. Daytime running light relay E103 5. Combination switch M28 6. Combination meter M24
Revision: March 2010 2008 QX56

FRONT FOG LAMPEXL-15
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FRONT FOG LAMP
System DiagramINFOID:0000000001547106
System DescriptionINFOID:0000000001547107
The front fog lamps are activated with the lighting switch (combination switch). The lighting switch signal to
the BCM is monitored with the BCM combination switch reading function. When the fog lamps are turned ON
with the lighting switch, the BCM sends a front fog lamp request signal via CAN communication lines to the
IPDM E/R. The IPDM E/R grounds the front fog la mp relay coil to activate the front fog lamps.
Component Parts LocationINFOID:0000000001547108
Component DescriptionINFOID:0000000001547109
FRONT FOG LAMP OPERATION
When the lighting switch is in front fog lamp ON posit ion and also in 1ST or 2ND position or AUTO position
(headlamp is ON), the BCM detects FR FOG ON and t he HEAD LAMP1, 2 ON or the AUTO LIGHT ON. The
BCM sends a front fog lamp request ON signal via the CAN communication lines to the IPDM E/R. The IPDM
E/R then turns ON the front fog lamp re lay sending power to the front fog lamps.
COMBINATION SWITCH READING FUNCTION
Refer to BCS-7, "System Description".
JPLIA0004GB
1. BCM M18, M20 (view with instrument
panel removed) 2. IPDM E/R E122, E123, E124 3. Combination switch M28
ALLIA0379ZZ
Revision: March 2010
2008 QX56

EXL-18
< FUNCTION DIAGNOSIS >
PARKING, LICENSE PLATE AND TAIL LAMPS
PARKING, LICENSE PLATE AND TAIL LAMPS
System DiagramINFOID:0000000001547114
System DescriptionINFOID:0000000001547115
PARKING, LICENCE PLATE AND TAIL LAMPS OPERATION
When the lighting switch is in 1ST position, BCM detects the LIGHTI NG SWITCH 1ST POSITION ON. The
BCM sends a parking light ON request via the CAN comm unication lines to the IPDM E/R. The IPDM E/R then
activates the tail lamp relay which sends power to the parking and instrument illumination circuits.
EXTERIOR LAMP BATTERY SAVER CONTROL
With the lighting switch (combination switch) in the 2nd position and the ignition switch is turned from ON or
ACC to OFF, the battery saver feature is activated.
Under this condition, the headlamps remain illuminated for 5 minutes unless the lighting switch position is
changed. If the lighting switch position is changed, then the headlamps are turned off.
This setting can be changed by CONSULT-III. Refer to EXL-23, "
EXTERNAL LAMP : CONSULT-III Function".
COMBINATION SWITCH READING FUNCTION
Refer to BCS-7, "System Description".
Component Parts LocationINFOID:0000000001547116
AWLIA0013GB
1. BCM M18, M20 (view with instrument
panel removed) 2. IPDM E/R E122, E124 3. Combination switch M28
ALLIA0379ZZ
Revision: March 2010
2008 QX56

PARKING, LICENSE PLATE AND TAIL LAMPS
EXL-19
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Component DescriptionINFOID:0000000001547117
Part name Description
BCM • Recieves lighting switch requests via BCM combination switch
reading function.
• Sends parking light request signal to the IPDM E/R.
IPDM E/R Activates the tail lamp relay upon request of the BCM.
Combination switch (lighting switch) Outputs lighting requests to the BCM.
Revision: March 2010 2008 QX56

EXL-20
< FUNCTION DIAGNOSIS >
TRAILER TOW
TRAILER TOW
System DiagramINFOID:0000000006095108
System DescriptionINFOID:0000000006095109
TRAILER TAIL LAMP OPERATION
The trailer tail lamps are controlled by the trailer tow relay 1 located behind the left side of the instrument panel
(IP). With the combination switch in the 1st position, the BCM detects the LIGHTING SWITCH 1ST POSITION
ON. The BCM sends a parking light ON request via the CAN communication lines to the IPDM E/R. The IPDM
E/R then activates the tail lamp relay which activates the trailer tow relay 1 and sends power to the trailer con-
nector.
TRAILER TURN SIGNAL LAMP OPERATION
The trailer turn signal lamps are controlled by the BCM. When the turn signal switch is in the LH or RH position
with the ignition switch ON, the combination switch sends a signal to the BCM. The BCM detects the TURN
RH or TURN LH ON request. The BCM sends a control signal to the respective trailer turn relay which sends
power to the trailer connector.
TRAILER HAZARD LAMP OPERATION
The trailer hazard lamps are controlled by the BCM. W hen the hazard switch is pressed, the BCM detects the
the hazard ON request. The BCM then sends a control si gnal to both trailer turn relays which sends power to
the trailer connector.
TRAILER BRAKE LAMP OPERATION
The trailer brake lamps are controlled by the BCM. When the brake pedal is depressed, the combination meter
receives a stop lamp switch signal from the stop lamp switch. The combination meter then sends the brake
signal to the BCM via the CAN communication lines. The BCM then sends a control signal to both trailer turn
relays which sends power to the trailer connector.
AWLIA1764GB
Revision: March 2010 2008 QX56

TRAILER TOWEXL-21
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Component Parts LocationINFOID:0000000006095110
Component DescriptionINFOID:0000000006095111
1. BCM M18, M19, M20 (view with instru- ment panel removed) 2. IPDM E/R E119, E122, E123, E124 3. Combination meter M23, M24
4. Combination switch M28 5. Trailer tow relay 1 M51 (view with
steering member removed) 6. Battery
7. Trailer turn relay LH E156 8. Trailer turn relay RH E157 9. Trailer tow relay 2 E140
10. Stop lamp switch E38
AWLIA1772ZZ
Part name Description
BCM • Receives lighting and turn signal requests from combination
switch.
• Receives stop lamp signal requests from combination meter via CAN communication.
• Sends lighting signal request to the IPDM E/R to control the tail
lamp relay via CAN communication.
• Sends turn/hazard/brake control signal to the trailer turn relays.
IPDM E/R Activates the tail lamp relay upon request from the BCM via CAN
communication.
Revision: March 2010
2008 QX56