steering INFINITI QX56 2006 Factory Workshop Manual

ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)BRC-67
[VDC/TCS/ABS]
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Revision: November 2009 2006 QX56
INSTALLATION
Installation is in the reverse order of removal.
NOTE:
To install, use a flare nut wrench (commercial service tool). Tighten brake tubes to specification when install-
ing. Refer to BR-12, "
Hydraulic Circuit" .

After installation of the ABS actuator and electric unit (control unit), refill the brake system with new brake
fluid. Refer to MA-11, "
RECOMMENDED FLUIDS AND LUBRICANTS" . Then bleed the air from the sys-
tem. Refer to BR-11, "
Bleeding Brake System" .
CAUTION:

Never reuse drained brake fluid.

Adjust the steering angle sensor. Refer to BRC-62, "Adjustment of Steering Angle Sensor Neu-
tral Position" .

Calibrate the yaw rate/side/decel G sensor. Refer to BRC-62, "Calibration of Decel G Sensor" .

BRC-68
[VDC/TCS/ABS]
STEERING ANGLE SENSOR
Revision: November 20092006 QX56
STEERING ANGLE SENSORPFP:25554
Removal and InstallationEFS0068G
The steering angle sensor is an integral part of the spiral cable. Refer to SRS-48, "Removal and Installation" .
CAUTION:
After installation of spiral cable, adjust steering angle sensor. Refer to BRC-62, "
Adjustment of Steer-
ing Angle Sensor Neutral Position" .

EC-5
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Revision: November 2009 2006 QX56
Component Description .......................................
. 440
On Board Diagnosis Logic .................................. . 440
DTC Confirmation Procedure .............................. . 440
Diagnostic Procedure .......................................... . 441
Removal and Installation ..................................... . 441
DTC P0500 VSS .................................................... . 442
Description .......................................................... . 442
On Board Diagnosis Logic .................................. . 442
DTC Confirmation Procedure .............................. . 442
Overall Function Check ....................................... . 442
Diagnostic Procedure .......................................... . 443
DTC P0506 ISC SYSTEM ...................................... . 444
Description .......................................................... . 444
On Board Diagnosis Logic .................................. . 444
DTC Confirmation Procedure .............................. . 444
Diagnostic Procedure .......................................... . 445
DTC P0507 ISC SYSTEM ...................................... . 446
Description .......................................................... . 446
On Board Diagnosis Logic .................................. . 446
DTC Confirmation Procedure .............................. . 446
Diagnostic Procedure .......................................... . 447
DTC P0550 PSP SENSOR .................................... . 448
Component Description ....................................... . 448
CONSULT-II Reference Value in Data Monitor Mode . 448
On Board Diagnosis Logic .................................. . 448
DTC Confirmation Procedure .............................. . 448
Wiring Diagram ................................................... . 449
Diagnostic Procedure .......................................... . 450
Component Inspection ........................................ . 452
Removal and Installation ..................................... . 452
DTC P0603 ECM POWER SUPPLY ...................... . 453
Component Description ....................................... . 453
On Board Diagnosis Logic .................................. . 453
DTC Confirmation Procedure .............................. . 453
Wiring Diagram ................................................... . 454
Diagnostic Procedure .......................................... . 455
DTC P0605 ECM ................................................... . 457
Component Description ....................................... . 457
On Board Diagnosis Logic .................................. . 457
DTC Confirmation Procedure .............................. . 457
Diagnostic Procedure .......................................... . 458
DTC P0643 SENSOR POWER SUPPLY ............... . 460
On Board Diagnosis Logic .................................. . 460
DTC Confirmation Procedure .............................. . 460
Wiring Diagram ................................................... . 461
Diagnostic Procedure .......................................... . 463
DTC P0850 PNP SWITCH ..................................... . 465
Component Description ....................................... . 465
CONSULT-II Reference Value in Data Monitor Mode . 465
On Board Diagnosis Logic .................................. . 465
DTC Confirmation Procedure .............................. . 465
Overall Function Check ....................................... . 466
Wiring Diagram ................................................... . 467
Diagnostic Procedure .......................................... . 468
DTC P1148, P1168 CLOSED LOOP CONTROL ... . 470
On Board Diagnosis Logic .................................. . 470
DTC P1211 TCS CONTROL UNIT ........................ . 471Description ...........................................................
.471
On Board Diagnosis Logic ................................... .471
DTC Confirmation Procedure .............................. .471
Diagnostic Procedure .......................................... .471
DTC P1212 TCS COMMUNICATION LINE ........... .472
Description ........................................................... .472
On Board Diagnosis Logic ................................... .472
DTC Confirmation Procedure .............................. .472
Diagnostic Procedure .......................................... .472
DTC P1217 ENGINE OVER TEMPERATURE ....... .473
Description ........................................................... .473
CONSULT-II Reference Value in Data Monitor Mode .473
On Board Diagnosis Logic ................................... .474
Overall Function Check ....................................... .474
Wiring Diagram .................................................... .476
Diagnostic Procedure .......................................... .478
Main 12 Causes of Overheating .......................... .481
Component Inspection ......................................... .482
DTC P1225 TP SENSOR ....................................... .483
Component Description ....................................... .483
On Board Diagnosis Logic ................................... .483
DTC Confirmation Procedure .............................. .483
Diagnostic Procedure .......................................... .484
Removal and Installation ..................................... .484
DTC P1226 TP SENSOR ....................................... .485
Component Description ....................................... .485
On Board Diagnosis Logic ................................... .485
DTC Confirmation Procedure .............................. .485
Diagnostic Procedure .......................................... .486
Removal and Installation ..................................... .486
DTC P1564 ICC STEERING SWITCH ................... .487
Component Description ....................................... .487
CONSULT-II Reference Value in Data Monitor Mode .487
On Board Diagnosis Logic ................................... .487
DTC Confirmation Procedure .............................. .488
Wiring Diagram .................................................... .489
Diagnostic Procedure .......................................... .490
Component Inspection ......................................... .493
DTC P1564 ASCD STEERING SWITCH ............... .494
Component Description ....................................... .494
CONSULT-II Reference Value in Data Monitor Mode .494
On Board Diagnosis Logic ................................... .494
DTC Confirmation Procedure .............................. .495
Wiring Diagram .................................................... .496
Diagnostic Procedure .......................................... .497
Component Inspection ......................................... .500
DTC P1568 ICC FUNCTION .................................. .501
On Board Diagnosis Logic ................................... .501
DTC Confirmation Procedure .............................. .501
Diagnostic Procedure .......................................... .501
DTC P1572 ICC BRAKE SWITCH ......................... .502
Component Description ....................................... .502
CONSULT-II Reference Value in Data Monitor Mode .502
On Board Diagnosis Logic ................................... .502
DTC Confirmation Procedure .............................. .503

EC-24Revision: November 2009
ENGINE CONTROL SYSTEM
2006 QX56
Multiport Fuel Injection (MFI) SystemUBS00KZ7
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation


During deceleration

During high engine speed operation
Sensor Input signal to ECMECM functionActuator
Crankshaft position sensor (POS) Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor
Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery Battery voltage*
3
Power steering pressure sensorPower steering operation
Heated oxygen sensor 2 Density of oxygen in exhaust gas*
1
ABS actuator and electric unit (control unit)VDC/TCS operation command*2
Air conditioner switch
Air conditioner operation*2
Wheel sensorVehicle speed*2

EC-28Revision: November 2009
AIR CONDITIONING CUT CONTROL
2006 QX56
AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartUBS00KZA
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
System DescriptionUBS00KZB
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.

When the accelerator pedal is fully depressed.

When cranking the engine.

At high engine speeds.

When the engine coolant temperature becomes excessively high.

When operating power steering during low engine speed or low vehicle speed.

When engine speed is excessively low.

When refrigerant pressure is excessively low or high.
SensorInput Signal to ECMECM functionActuator
Air conditioner switch Air conditioner ON signal*
1
Air conditioner
cut controlAir conditioner relay
Accelerator pedal position sensor
Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
2
Engine coolant temperature sensor
Engine coolant temperature
Battery Battery voltage*
2
Refrigerant pressure sensorRefrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor Vehicle speed*
1

AUTOMATIC SPEED CONTROL DEVICE (ASCD)EC-29
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Revision: November 2009 2006 QX56
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionUBS00KZC
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
NOTE:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
SET OPERATION
Press MAIN switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press SET/COAST switch. (Then SET indicator in combination meter illuminates.)
ACCELERATE OPERATION
If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until
the switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.

CANCEL switch is pressed

More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)

Brake pedal is depressed

Selector lever is changed to N, P, R position

Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed

VDC system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.

Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing SET/COAST switch or RESUME/
ACCELERATE switch.

Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
Sensor Input signal to ECM ECM functionActuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator
Stop lamp switch
Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switch Gear position
Wheel sensor Vehicle speed*
TCM Powertrain revolution*

EC-30Revision: November 2009
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
2006 QX56
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
RESUME OPERATION
When the RESUME/ACCELERATE switch is pressed after cancel operation other than pressing MAIN switch
is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must
meet following conditions.

Brake pedal is released

A/T selector lever is in other than P and N positions

Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
Component DescriptionUBS00KZD
ASCD STEERING SWITCH
Refer to EC-494 .
ASCD BRAKE SWITCH
Refer to EC-511 , and EC-586 .
STOP LAMP SWITCH
Refer to EC-511 , EC-523 and EC-586 .
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EC-528 , EC-534 , EC-540 and EC-545 .
ASCD INDICATOR
Refer to EC-593 .

BASIC SERVICE PROCEDUREEC-71
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Revision: November 2009 2006 QX56
BASIC SERVICE PROCEDUREPFP:00018
Basic InspectionUBS00KZU
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for scheduled maintenance.
2. Open engine hood and check the following:
–Harness connectors for improper connections
–Wiring harness for improper connections, pinches and cut
–Vacuum hoses for splits, kinks and improper connections
–Hoses and ducts for leaks
–Air cleaner clogging
–Gasket
3. Confirm that electrical or mechanical loads are not applied.
–Headlamp switch is OFF.
–Air conditioner switch is OFF.
–Rear window defogger switch is OFF.
–Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF983U
SEF976U
SEF977U

EC-78Revision: November 2009
BASIC SERVICE PROCEDURE
2006 QX56
Accelerator Pedal Released Position LearningUBS00KZY
DESCRIPTION
Accelerator Pedal Released Position Learning is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position LearningUBS00KZZ
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to learn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF wait at least 10 seconds.Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningUBS00L00
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:

Each time electric throttle control actuator or ECM is replaced.

Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.

Battery voltage: More than 12.9V (At idle)

Engine coolant temperature: 70 - 100 °C (158 - 212 °F)

Park/Neutral position (PNP) switch: ON

Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine
is start the headlamp will not be illuminated.

Steering wheel: Neutral (Straight-ahead position)

Vehicle speed: Stopped

Transmission: Warmed-up
–With CONSULT-II: Drive vehicle until “ATF TEMP SE 1 ” in “DATA MONITOR” mode of “A/T” system indi-
cates less than 0.9V.
–Without CONSULT-II: Drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-78, "Accelerator Pedal Released Position Learning" .
2. Perform EC-78, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.

EC-90Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
2
P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater

P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater

P0130 P0131 P0132 P0133 P0150 P0151 P0152 P0153 P2A00 P2A03 Air fuel ratio (A/F) sensor 1

P0137 P0138 P0139 P0157 P0158 P0159 Heated oxygen sensor 2

P0441 EVAP control system purge flow monitoring

P0443 P0444 P0445 EVAP canister purge volume control solenoid valve

P0447 P0448 EVAP canister vent control valve

P0451 P0452 P0453 EVAP control system pressure sensor

P0550 Power steering pressure sensor

P0603 ECM power supply

P0700 P0710 P0717 P0720 P0740 P0744 P0745 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767 P1769
P1772 P1774 A/T related sensors and solenoid valves

P1217 Engine over temperature (OVERHEAT)

P1805 Brake switch

P2100 P2103 P2118 Electric throttle control actuator

P2101 Electric throttle control function
3

P0171 P0172 P0174 P0175 Fuel injection system function

P0300 - P0308 Misfire

P0420 P0430 Three way catalyst function

P0442 P0455 P0456 EVAP control system

P0506 P0507 Idle speed control system

P1148 P1168 Closed loop control

P1211 TCS control unit

P1212 TCS communication line

P1564 ICC/ASCD steering switch

P1568 ICC command value

P1572 ICC/ASCD brake switch

P1574 ICC/ASCD vehicle speed sensor

P2119 Electric throttle control actuator
Priority Detected items (DTC)