2011 INFINITI QX56 relay

ENGINE CONTROL SYSTEM SYMPTOMSEC-525
< SYMPTOM DIAGNOSIS > [VK56VD]
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EC
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Mass air flow sensor circuit
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12 2
222 2 EC-201
Engine coolant temperature sensor circuit
333
EC-217
Air fuel ratio (A/F) sensor 1 circuit EC-181
EC-228
EC-232
EC-235
EC-238
Throttle position sensor circuit
22EC-219
EC-288
EC-406
EC-407
EC-475
Accelerator pedal position sensor circuit 3 2 1
EC-468EC-471
EC-478
Knock sensor circuit 2 3
EC-297
Engine oil temperature sensor 4 2 3EC-285
Crankshaft position sensor circuit 2 2EC-299
Camshaft position sensor circuit 3 2EC-303
Vehicle speed signal circuit 2 3 3 3EC-356
Power steering pressure sensor circuit 2 3 3EC-371
ECM 22333333333EC-376EC-378
EC-380
Intake valve timing control solenoid valve cir-
cuit
32 13223 3
EC-193
VVEL control module 3 4 4 3 EC-451EC-452
VVEL actuator motor 3 4 4 3
EC-390
VVEL actuator motor relay 3 4 4 3EC-393
VVEL control shaft position sensor 3 4 4 3EC-387
PNP signal circuit 3 3 3 3 3EC-383
Refrigerant pressure sensor circuit 2 3 3 4EC-520
Electrical load signal circuit 3EC-493
Air conditioner circuit 223333333 3 2HAC-60
ABS actuator and electric unit (control unit) 4BRC-60
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: 2010 May2011 QX56

COMPONENT PARTSEXL-7
< SYSTEM DESCRIPTION > [XENON TYPE]
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*1: With headlamp aiming control system (manual) models
*2: With AFS system models
EXTERIOR LIGHTING SYSTEM : Component DescriptionINFOID:0000000006213888
1. Combination meter 2. BCM
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Compon ent Parts Loca-
tion"
3. Optical sensor
4. IPDM E/R Refer to PCS-4, "
Component Parts
Location"
5. ECM
Refer to EC-16, "
Component Parts
Location"
6. Parking lamp
7. Front turn signal lamp 8. Front fog lamp 9. Headlamp
10. Front side marker lamp 11. Combination switch 12. Headlamp aiming switch*
1
13. Front door switch (driver side) 14.
Steering angle sensor*2
Refer to BRC-10, "Component Parts
Location"
15. License plate lamp
16. Tail lamp 17. Rear turn signal lamp 18. Rear side marker lamp
19. Hazard switch 20. Side turn signal lamp 21. Headlamp swivel actuator
22. Headlamp aiming motor 23. AFS switch*
224.Rear height sensor*2
25.AFS control unit*226.Front height sensor*2
A. Front combination lamp (back) B. View with instrument driver lower
panel (LH)C. Rear suspension member (RH)
D. View with instrument lower cover E. Front suspension arm (RH)
Part Description
BCM Controls the exterior lighting system.
ECM*
1Transmits engine speed signal to AFS control unit. (via CAN communication)
TCM*
1Transmits Shift position signal to AFS control unit. (via CAN communication)
IPDM E/R Controls the integrated relay, and supplies voltage to the load according to the request
from BCM (via CAN communication).
AFS control unit*
1AFS control unit judges the vehicle condition from each signal. AFS control unit con-
trols AFS function and the headlamp aiming.
Combination meter  Outputs the vehicle speed signal (8-pulse) to AFS control unit.
 Blinks the turn signal indicator lamp and outputs the turn signal operating sound with
integrated buzzer according to the request from BCM (via CAN communication).
 Turns the tail lamp indicator lamp and high beam indicator lamp ON according to the
request from BCM (via CAN communication).
 Turns the AFS OFF indicator lamp ON/OFF /blinking according to the request from
AFS control unit (via CAN communication).
Headlamp assembly Xenon bulb Refer to
EXL-8, "
FRONT COMBINATION LAMP : Xenon Headlamp".
HID control unit Refer to EXL-9, "
FRONT COMBINATION LAMP : HID control unit".
High beam solenoid Refer to EXL-9, "
FRONT COMBINATION LAMP : High Beam Solenoid".
Aiming motor Refer to EXL-9, "
FRONT COMBINATION LAMP : Aiming Motor".
Swivel actuator*
1Refer to EXL-9, "FRONT COMBINATION LAMP : Swivel Actuator".
Height sensor*
1
 The height sensor is installed to the front suspension member and rear suspension member.
 The height sensor detects the suspension arm displacement as the vehicle height change.
 The height sensor transmits the height sensor signal to AFS control unit.
NOTE:
The sensor angle of the unloaded vehicle position is the reference value.
Optical sensor Optical sensor converts the outside brightness (lux) to voltage and transmits the opti-
cal sensor signal to BCM.
Revision: 2010 May2011 QX56

COMPONENT PARTSEXL-9
< SYSTEM DESCRIPTION > [XENON TYPE]
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FRONT COMBINATION LAMP : HID control unitINFOID:0000000006213890
Headlamp (LO) circuit is connected to HID control unit integrated in the headlamp. Headlamp (LO) circuit turns
xenon headlamp ON.
For the details of HID control unit and the xenon headlamp, refer to EXL-8, "
FRONT COMBINATION LAMP :
Xenon Headlamp".
FRONT COMBINATION LAMP : High Beam SolenoidINFOID:0000000006213891
The high beam solenoid drives the mobile valve shade. And the mobile valve shade switches the high beam
and low beam of headlamp.
 When the headlamp high relay is turned ON, magnetic force is applied to the high beam solenoid (1) by a current. The mobile
valve shade (2) is switched to the high beam position.
 When the headlamp high relay is turned OFF, the current stops.
The mobile valve shade returns to the low beam position automati-
cally.
FRONT COMBINATION LAMP : Aiming MotorINFOID:0000000006213892
The headlamp levelizer adjusts the headlamp light axis upward and downward with the aiming motor inte-
grated in the front combination lamp.
FRONT COMBINATION LAMP : Swivel ActuatorINFOID:0000000006213893
SWIVEL ACTUATOR
The swivel actuator is installed in the headlamp unit. T he swivel actuator consists of the swivel motor and the
swivel position sensor.
SWIVEL MOTOR
 The swivel motor is the two-phase step motor.
 The swivel motor drives headlamp by exciting the two dr ive coils according to the drive signal from AFS con-
trol unit.
 The rotation direction of the swivel motor is changeable by changing the exciting pattern.
SWIVEL POSITION SENSOR
The swivel position sensor detects the headlamp swivel angle to transmit t he swivel position sensor signal to
AFS control unit.
JSLIA0129ZZ
Revision: 2010 May2011 QX56

EXL-10
< SYSTEM DESCRIPTION >[XENON TYPE]
SYSTEM
SYSTEM
HEADLAMP SYSTEM
HEADLAMP SYSTEM : System DiagramINFOID:0000000006213894
HEADLAMP SYSTEM : System DescriptionINFOID:0000000006213895
OUTLINE
Headlamp is controlled by combination switch r
eading function and headlamp control function of BCM, and
relay control function of IPDM E/R.
HEADLAMP (LO) OPERATION
 BCM detects the combination switch conditi on with the combination switch reading function.
 BCM transmits the low beam request signal to IPDM E/R via CAN communication according to the head-
lamp (LO) ON condition.
Headlamp (LO) ON condition- Lighting switch 2ND
- Lighting switch AUTO (auto light function ON judgment)
- Lighting switch AUTO, with the front fog la mp switch ON and the ignition switch ON
- Lighting switch PASS
 IPDM E/R turns the integrated headlamp low relay ON , and turns the headlamp ON according to the low
beam request signal.
HEADLAMP (HI) OPERATION
 BCM transmits the high beam request signal to IPDM E/R and the combination meter via CAN communica- tion according to the headlamp (HI) ON condition.
Headlamp (HI) ON condition
- Lighting switch HI with the lighting switch 2ND or AUTO (auto light function ON judgment)
- Lighting switch PASS
- Lighting switch AUTO, with the front fog lamp swit ch ON, the ignition switch ON and lighting switch HI
 Combination meter turns the high beam indicator lamp ON according to the high beam request signal.
 IPDM E/R turns the integrated headlamp high relay ON , and turns the headlamp ON according to the high
beam request signal.
HEADLAMP SYSTEM : Fail-safeINFOID:0000000006213896
CAN COMMUNICATION CONTROL
When CAN communication with BCM is impossible, IPDM E/R performs fail-safe control. After CAN communi-
cation recovers normally, it also returns to normal control.
If No CAN Communication Is Available With BCM
JMLIA1083GB
Revision: 2010 May2011 QX56

SYSTEMEXL-11
< SYSTEM DESCRIPTION > [XENON TYPE]
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*: With daytime running light system
AUTO LIGHT SYSTEM
AUTO LIGHT SYSTEM : System DiagramINFOID:0000000006213897
AUTO LIGHT SYSTEM : System Description (For CANADA)INFOID:0000000006218912
OUTLINE
 Auto light system is controlled by each function of BCM and IPDM E/R.
Control by BCM- Combination switch reading function
- Headlamp control function
- Auto light function
- Delay timer function
- Wiper linked auto lighting function
- Auto light adjustment system
Control by IPDM E/R
- Relay control function
 Auto light system has the auto light function, wiper linked auto lighting function and delay timer function.
- Auto light function automatically turns ON/OFF the exterior lamps* and each illumination automatically,
depending on the outside brightness.
- Wiper linked auto lighting function automatically tu rns ON/OFF the exterior lamps* and each illumination
when the light switch is in the AUTO posit ion, according to a front wiper operation.
- When auto light system turns the exterior lamps ON wit h the ignition switch OFF, delay timer function turns
the exterior lamps OFF, depending on the vehicle condition with the auto light function after a certain period
of time.
*: Headlamp (LO/HI), parking lamp, side marker lamp, tail lamp and front fog lamp (Headlamp HI and front fog
lamp depend on the combination switch condition.)
AUTO LIGHT FUNCTION
 BCM detects the combination switch conditi on with the combination switch reading function.
 BCM supplies voltage to optical sensor when the ignition switch is turned ON or ACC.
 Optical sensor converts outside brightness (lux) to voltage and transmits the optical sensor signal to BCM.
 BCM judges outside brightness from the optical sens or signal and judges ON/OFF condition of the exterior
lamp and each illumination according to the outside brightness.
Control part Fail-safe operation
Headlamp  Turns ON the headlamp low relay when the ignition switch is turned ON
 Turns OFF the headlamp low relay when the ignition switch is turned OFF
 Headlamp high relay OFF
JMLIA1254GB
Revision: 2010 May2011 QX56

EXL-12
< SYSTEM DESCRIPTION >[XENON TYPE]
SYSTEM
 BCM transmits each request signal to IPDM E/R wit
h CAN communication according to ON/OFF condition
by the auto light function.
NOTE:
ON/OFF timing differs based on the sensit ivity from the setting. The setting can be set by CONSULT-III. Refer
to EXL-23, "
HEADLAMP : CONSULT-III Function (BCM - HEAD LAMP)".
AUTO LIGHT ADJUSTMENT SYSTEM
The auto light adjustment system automatically, dims/bri ghtens the display and combination meter, according
to brightness outside the vehicle, when lighting switch 1ST or lighting switch 2ND is operated. Refer to INL-11,
"AUTO LIGHT ADJUSTMENT SYSTEM : System Description".
DELAY TIMER FUNCTION
BCM turns the exterior lamp OFF depending on the vehicle condition with the auto light function when the igni-
tion switch is turned OFF.
 Turns the exterior lamp OFF 5 minutes afte r detecting that any door opens. (Door switch ON).
 Turns the exterior lamp OFF a certain period of time* after closing all doors. (Door switch ON →OFF).
 Turns the exterior lamp OFF with the igni tion switch ACC or the light switch OFF.
*: The preset time is 45 seconds. The timer operat ing time can be set by CONSULT-III. Refer to EXL-23,
"HEADLAMP : CONSULT-III Function (BCM - HEAD LAMP)".
NOTE:
When any position other than the light switch AUTO is set, the auto light system function switches to the exte-
rior lamp battery saver function.
AUTO LIGHT SYSTEM : System De scription (Except for CANADA)INFOID:0000000006218908
OUTLINE
 Auto light system is controlled by each function of BCM and IPDM E/R.
Control by BCM- Combination switch reading function
- Headlamp control function
- Auto light function
- Delay timer function
- Wiper linked auto lighting function
- Auto light adjustment system
Control by IPDM E/R- Relay control function
 Auto light system has the auto light function (with twilight lighting function), wiper linked auto lighting function
and delay timer function.
- Auto light function automatically turns ON/OFF the exterior lamps* and each illumination automatically,
depending on the outside brightness.
- Wiper linked auto lighting function automatically turn s ON/OFF the exterior lamps* and each illumination
when the light switch is in the AUTO posit ion, according to a front wiper operation.
- When auto light system turns the exterior lamps ON with the ignition switch OFF, delay timer function turns the exterior lamps OFF, depending on the vehicle conditi on with the auto light function after a certain period
of time.
*: Headlamp (LO/HI), parking lamp, side marker lamp, tail lamp and front fog lamp (Headlamp HI and front fog
lamp depend on the combination switch condition.)
NOTE:
The settings of the twilight lighting function and the wiper linked auto lighting function can be changed with
CONSULT-III. Refer to EXL-23, "
HEADLAMP : CONSULT-III Function (BCM - HEAD LAMP)".
AUTO LIGHT FUNCTION (WITH TWILIGHT LIGHTING FUNCTION)
Description
 BCM detects the combination switch conditi on with the combination switch reading function.
 BCM supplies voltage to the optical sensor when the ignition switch is turned ON or ACC.
 Optical sensor converts outside brightness (lux) to voltage and transmits the optical sensor signal to BCM.
 When ignition switch is turned ON, BCM detects out side brightness from the optical sensor signal and
judges ON/OFF condition of the exterior lamp and each illumination, depending on the outside brightness
condition (standard or twilight).
Revision: 2010 May2011 QX56

EXL-14
< SYSTEM DESCRIPTION >[XENON TYPE]
SYSTEM
AUTO LIGHT ADJUSTMENT SYSTEM
The auto light adjustment system automatically, dims/bri
ghtens the display and combination meter, according
to brightness outside the vehicle, when lighting switch 1ST or lighting switch 2ND is operated. Refer to INL-11,
"AUTO LIGHT ADJUSTMENT SYSTEM : System Description".
DELAY TIMER FUNCTION
BCM turns the exterior lamp OFF depending on the vehicle condition with the auto light function when the igni-
tion switch is turned OFF.
 Turns the exterior lamp OFF 5 minutes afte r detecting that any door opens. (Door switch ON).
 Turns the exterior lamp OFF a certain period of time* after closing all doors. (Door switch ON →OFF).
 Turns the exterior lamp OFF with the igni tion switch ACC or the light switch OFF.
*: The preset time is 45 seconds. The timer operat ing time can be set by CONSULT-III. Refer to EXL-23,
"HEADLAMP : CONSULT-III Function (BCM - HEAD LAMP)".
NOTE:
When any position other than the light switch AUTO is set, the auto light system function switches to the exte-
rior lamp battery saver function.
DAYTIME RUNNING LIGHT SYSTEM
DAYTIME RUNNING LIGHT S YSTEM : System DiagramINFOID:0000000006214028
DAYTIME RUNNING LIGHT SYSTEM : System DescriptionINFOID:0000000006214029
OUTLINE
 Turns the front fog lamp ON as the daytime running light.
 Daytime running light is controlled by daytime runni ng light control function and combination switch reading
function of BCM, and relay c ontrol function of IPDM E/R.
DAYTIME RUNNING LIGHT OPERATION
 BCM detects the combination switch conditi on by the combination switch reading function.
 BCM detects the vehicle condition depending on the following signals.
- Parking brake switch signal (received from combination meter via CAN communication)
 BCM transmits the front fog light request signal to IPDM E/R via CAN communication according to the day-
time running light ON condition.
Daytime running light ON condition- While the engine running with the parking brake released
- Lighting switch OFF
- Lighting switch AUTO (auto light function OFF judgment)
- Passing switch OFF
- Front fog lamp switch OFF
 IPDM E/R turns the integrated front fog lamp relay ON and turns the front fog lamp ON according to the front
fog light request signal.
ACTIVE ADAPTIVE FRONT-LIGHTING SYSTEM
JMLIA1078GB
Revision: 2010 May2011 QX56

SYSTEMEXL-19
< SYSTEM DESCRIPTION > [XENON TYPE]
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agramINFOID:0000000006213903
PARKING, LICENSE PLATE, SIDE MARKER AND TAIL LAMP SYSTEM : System De-
scription
INFOID:0000000006213904
OUTLINE
Parking, license plate, side marker and tail lamps ar e controlled by combination switch reading function and
headlamp control function of BCM, and re lay control function of IPDM E/R.
PARKING, LICENSE PLATE, SIDE MARKER AND TAIL LAMPS OPERATION
 BCM detects the combination switch conditi on by the combination switch reading function.
 BCM transmits the position light request signal to IPDM E/R and the combination meter via CAN communi-
cation according to the ON/OFF condition of the pa rking, license plate, side marker and tail lamps.
Parking, license plate, side marker and tail lamps ON condition- Lighting switch 1ST
- Lighting switch 2ND
- Lighting switch AUTO, and the auto light function ON judgment
- Lighting switch AUTO, with the front fog lamp switch ON and the ignition switch ON
 IPDM E/R turns the integrated tail lamp relay ON and tu rns the parking, license plate, side marker and tail
lamps ON according to the position light request signal.
 Combination meter turns the tail lamp indicator lamp ON according to the position light request signal.
PARKING, LICENSE PLATE, SIDE MARKER AND TAIL LAMP SYSTEM : Fail-safe
INFOID:0000000006213905
CAN COMMUNICATION CONTROL
When CAN communication with BCM is impossible, IPDM E/R performs fail-safe control. After CAN communi-
cation recovers normally, it also returns to normal control.
If No CAN Communication Is Available With BCM
*: With daytime running light system
FRONT FOG LAMP SYSTEM
JMLIA0687GB
Control part Fail-safe operation
Parking lamps
 License plate lamps
 Illuminations
 Tail lamps  Turns ON the tail lamp relay and daytime running light relay
* when the ignition switch
is turned ON
 Turns OFF the tail lamp relay and daytime running light relay
* when the ignition switch
is turned OFF
Revision: 2010 May2011 QX56