2005 INFINITI QX4 steering wheel

TROUBLE DIAGNOSIS
BRC-33
[VDC/TCS/ABS]
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BRC
Revision: October 20052005 QX56
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
2. Touch “START (NISSAN BASED VHCL)”, “ABS”, “DATA MONITOR” in order on the CONSULT-II screen.
If “ABS” is not indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
CAUTION:
When “START (NISSAN BASED VHCL)” is touched immediately after starting the engine or turning
on the ignition switch, “ABS” might not be displayed in the system selection screen. In this case,
repeat the operation from step 2.
3. Return to the Monitor Item Selection screen, and touch “ECU INPUT SIGNALS”, “MAIN SIGNALS”, or
“SELECTION FROM MENU”. Refer to the following information.
4. When “START” is touched, the data monitor screen is displayed.
Display Item List
Item
(Unit)Data monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELECTION
FROM MENU
GEAR×××Gear position judged by PNP
switch signal is displayed.
FR RH SENSOR
(km/h, MPH)×××Wheel speed calculated by front
RH wheel sensor signal is dis-
played.
FR LH SENSOR
(km/h, MPH)×××Wheel speed calculated by front LH
wheel sensor signal is displayed.
RR RH SENSOR
(km/h, MPH)×××Wheel speed calculated by rear RH
wheel sensor signal is displayed.
RR LH SENSOR
(km/h, MPH)×××Wheel speed calculated by rear LH
wheel sensor signal is displayed.
BATTERY VOLT
(V)×××Voltage supplied to ABS actuator
and electric unit (control unit) is dis-
played.
N POSI SIG – –×Shift position judged by PNP switch
signal.
P POSI SIG – –×Shift position judged by PNP switch
signal.
ACCEL POS SIG
(%)×–×Throttle valve open/close status
judged by CAN communication sig-
nal is displayed.
ENGINE SPEED
(rpm)×××Engine speed judged by CAN com-
munication signal is displayed.
STR ANGLE SIG
(deg)×–×Steering angle detected by steering
angle sensor is displayed.
YA W R AT E S E N
(d/s)×××Yaw rate detected by yaw rate sen-
sor is displayed.
DECEL G SEN
(d/s)×××Longitudinal acceleration detected
by decel G-sensor is displayed.
SIDE G-SENSOR
(m/s
2 )×– ×Transverse acceleration detected
by side G-sensor is displayed.
STOP LAMP SW
(ON/OFF)×××Stop lamp switch (ON/OFF) status
is displayed.
OFF SW
(ON/OFF) ×× ×VDC OFF switch (ON/OFF) status
is displayed.
ABS WARN LAMP
(ON/OFF)–××ABS warning lamp (ON/OFF) status
is displayed.

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-41
[VDC/TCS/ABS]
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BRC
Revision: October 20052005 QX56
Steering Angle Sensor SystemEFS004XU
INSPECTION PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULT
Check self-diagnosis results.
Is above displayed in self-diagnosis item?
YES >> GO TO 2.
NO >> Inspection End.
2. CHECK CONNECTOR
1. Disconnect steering angle sensor connector M47 and ABS actuator and electric unit (control unit) connec-
tor E125 and check terminals for deformation, disconnection, looseness, or damage. Repair or replace as
necessary.
2. Reconnect connectors and repeat ABS actuator and electric unit (control unit) self-diagnosis.
IS "ST ANGLE SEN CIRCUIT" or "ST ANG SEN COM CIR" DISPLAYED?
YES >> GO TO 3.
NO >> Inspection End.
3. CHECK STEERING ANGLE SENSOR HARNESS
1. Check CAN communication system. Refer to LAN-5, "
CAN COMMUNICATION" .
2. Turn ignition switch OFF and disconnect steering angle sensor
connector M47 and ABS actuator and electric unit (control unit)
connector E125.
3. Check continuity between ABS actuator and electric unit (control
unit) connector E125 and steering angle sensor connector M47.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness.
4. CHECK DATA MONITOR
1. Connect steering angle sensor and ABS actuator and electric unit (control unit) connectors.
2. Use “DATA MONITOR” to check if the status of "STR ANGLE SIG" is normal.
OK or NG
OK >> Perform ABS actuator and electric unit (control unit) self-diagnosis again.
NG >> Replace spiral cable (steering angle sensor) and adjust neutral position of steering angle sensor.
Refer to BRC-62, "
Adjustment of Steering Angle Sensor Neutral Position" .
Self-diagnosis results
ST ANGLE SEN CIRCUIT
ST ANG SEN COM CIR
ABS actuator and
electric unit (con-
trol unit) harness
connector E125Steering angle
sensor
harness con-
nector M47Continuity
11 (L) 3 (L) Yes
15 (P) 4 (P) Yes
WFIA0224E
Steering condition Data monitor
Straight-ahead –3.5 deg to +3.5 deg
Turn wheel to the right by 90°Approx. - 90deg
Turn wheel to the left by 90°Approx. + 90deg

BRC-62
[VDC/TCS/ABS]
ON-VEHICLE SERVICE
Revision: October 20052005 QX56
ON-VEHICLE SERVICEPFP:00000
Adjustment of Steering Angle Sensor Neutral PositionEFS004YH
After removing/installing or replacing ABS actuator and electric unit (control unit), steering angle sensor, steer-
ing and suspension components which affect wheel alignment or after adjusting wheel alignment, be sure to
adjust neutral position of steering angle sensor before running vehicle.
NOTE:
Adjustment of steering angle sensor neutral position requires CONSULT-II.
1. Stop vehicle with front wheels in straight-ahead position.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector on vehicle, and turn ignition switch ON (do not
start engine).
3. Touch “ABS”, “WORK SUPPORT” and “ST ANGLE SENSOR
ADJUSTMENT” on CONSULT-II screen in this order.
4. Touch “START”.
CAUTION:
Do not touch steering wheel while adjusting steering angle
sensor.
5. After approximately 10 seconds, touch “END”. (After approxi-
mately 60 seconds, it ends automatically.)
6. Turn ignition switch OFF, then turn it ON again.
7. Run vehicle with front wheels in straight-ahead position, then
stop.
8. Select “DATA MONITOR”, “SELECTION FROM MENU”, and
“STR ANGLE SIG” on CONSULT-II screen. Then check that
“STR ANGLE SIG” is within 0±3.5 deg. If value is more than specification, repeat steps 1 to 5.
9. Erase memory of ABS actuator and electric unit (control unit) and ECM.
10. Turn ignition switch to OFF.
Calibration of Decel G SensorEFS004YI
After removing/installing or replacing ABS actuator and electric unit (control unit), yaw rate/side/decel G sen-
sor, steering and suspension components which affect wheel alignment or after adjusting wheel alignment, be
sure to calibrate the decel G sensor before running vehicle.
NOTE:
Calibration of decel G sensor requires CONSULT-II.
1. Stop vehicle with front wheels in straight-ahead position.
CAUTION:

The work should be done on a level area with an unloaded vehicle.

Keep all the tires inflated to the correct pressures. Adjust the tire pressure to the specified pres-
sure value.
2. Connect CONSULT-II with CONSULT-II CONVERTER to data link connector on vehicle, and turn ignition
switch ON (do not start engine).
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
3. Touch "ABS", "WORK SUPPORT" and "DECEL G SEN CALIBRATION" on CONSULT-II screen in this
order. Refer to BRC-28, "
CONSULT-II BASIC OPERATION PROCEDURE" .
BBIA0369E
WFIA0239E

EC-24Revision: October 2005
ENGINE CONTROL SYSTEM
2005 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 ECM ECM function Actuator
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 sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)*
2VDC/TCS operation command
Air conditioner switch*
2Air conditioner operation
Wheel sensor*
2Vehicle speed

EC-28Revision: October 2005
AIR CONDITIONING CUT CONTROL
2005 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.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch*
1Air conditioner ON signal
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 sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed

AUTOMATIC SPEED CONTROL DEVICE (ASCD)
EC-29
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EC
Revision: October 20052005 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.)
ACCEL 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 function Actuator
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)
switchGear position
Wheel sensor* Vehicle speed
TCM* Powertrain revolution

EC-72Revision: October 2005
BASIC SERVICE PROCEDURE
2005 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.
SEF 9 83 U
SEF 9 76 U
SEF 9 77 U

BASIC SERVICE PROCEDURE
EC-81
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Revision: October 20052005 QX56
DETAILED PROCEDURE
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.
–Head lamp 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.
SEF 9 83 U
SEF 9 76 U
SEF 9 77 U