2006 INFINITI QX56 power steering

TROUBLE DIAGNOSISBRC-25
[VDC/TCS/ABS]
C
DE
G H
I
J
K L
M A
B
BRC
Revision: November 2009 2006 QX56
STR ANGLE SIGSteering angle
detected by steering
angle sensorStraight-ahead
Approx. 0 deg
BRC-40, "Steering Angle
Sensor System"Steering wheel turned –756 to 756 deg
YAW RATE SEN Yaw rate detected by
yaw rate sensorVehicle stopped Approx. 0 d/s
BRC-41, "
Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running–100 to 100 d/s
SIDE G-SENSOR Transverse G detected
by side G-sensorVehicle stopped
Approx. 0 m/s
2BRC-41, "Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running–16.7 to 16.7 m/s2
BATTERY VOLT Battery voltage sup-
plied to ABS actuator
and electric unit (con-
trol unit)Ignition switch ON
10 to 16VBRC-46, "
ABS/TCS/VDC
Control Unit Power and
Ground Systems Inspec-
tion"
STOP LAMP SW
Stop lamp switch oper-
ationBrake pedal depressed ON
BRC-45, "
Stop Lamp
Switch System Inspec-
tion"Brake pedal not depressed OFF
OFF SW VDC OFF switch
ON/OFF status VDC OFF switch ON
(When VDC OFF indicator
lamp is ON)
ON
BRC-56, "
VDC OFF
SWITCH"VDC OFF switch OFF
(When VDC OFF indicator
lamp is OFF) OFF
ABS WARN LAMP ABS warning lamp ON
condition (Note 2)ABS warning lamp ON ON
—
ABS warning lamp OFF OFF
MOTOR RELAY Operation status of
motor and motor relayIgnition switch ON or running
(ABS not activated)
OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Ignition switch ON or engine
running (ABS activated) ON
ACTUATOR RLY Actuator relay opera-
tion statusVehicle stopped (Ignition
switch ON)
OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Vehicle stopped (Engine run-
ning) ON
OFF LAMP VDC OFF indicator
lamp status (Note 3) When VDC OFF indicator
lamp is ON
ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When VDC OFF indicator
lamp is OFF OFF
SLIP LAMP SLIP indicator lamp
status (Note 4)When SLIP indicator lamp is
ON
ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When SLIP indicator lamp is
OFF OFF
Monitor item
Display content Data monitor
Note: Error inspection
checklist
Condition Reference value in
normal operation

BRC-30
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Display Item List
Self-diagnostic itemMalfunction detecting condition Check system
FR LH SENSOR 1
[C1104] Circuit of front LH wheel sensor is open, shorted or sensor power
voltage is unusual.
BRC-38, "
Wheel Sensor
System Inspection"
(Note 1)
RR RH SENSOR 1
[C1101]
Circuit of rear RH wheel sensor is open, shorted or sensor power
voltage is unusual.
FR RH SENSOR 1
[C1103] Circuit of front RH wheel sensor is open, shorted or sensor power
voltage is unusual.
RR LH SENSOR 1
[C1102] Circuit of rear LH wheel sensor is open, shorted or sensor power
voltage is unusual.
FR LH SENSOR 2
[C1108] ABS actuator and electric unit (control unit) cannot identify sen-
sor pulses, because of large gap between wheel sensor and sen-
sor rotor.
RR RH SENSOR 2
[C1105] ABS actuator and electric unit (control unit) cannot identify sen-
sor pulses, because of large gap between wheel sensor and sen-
sor rotor.
FR RH SENSOR 2
[C1107] ABS actuator and electric unit (control unit) cannot identify sen-
sor pulses, because of large gap between wheel sensor and sen-
sor rotor.
RR LH SENSOR 2
[C1106] ABS actuator and electric unit (control unit) cannot identify sen-
sor pulses, because of large gap between wheel sensor and sen-
sor rotor.
ABS SENSOR
[C1115] Wheel sensor input is abnormal.
STOP LAMP SW
[C1116] Stop lamp switch or circuit malfunction. BRC-45, "
Stop Lamp
Switch System Inspec-
tion"
DECEL G SEN SET
[C1160]
ABS decel sensor adjustment is incomplete. BRC-55, "Inspection For
Self-diagnosis Result
"DECEL G SEN SET""
ST ANGL SEN SAFE
[C1163]
When steering angle sensor is in safe mode. BRC-53, "Steering Angle
Sensor Safe Mode
Inspection"
ST ANG SEN CIRCUIT
[C1143]
Neutral position of steering angle sensor is dislocated, or steer-
ing angle sensor is malfunctioning. BRC-40, "Steering Angle
Sensor System"
YAW RATE SENSOR
[C1145]Yaw rate sensor has generated an error, or yaw rate sensor sig-
nal line is open or shorted. BRC-41, "Yaw Rate/
Side/Decel G Sensor
System Inspection"

TROUBLE DIAGNOSISBRC-31
[VDC/TCS/ABS]
C
DE
G H
I
J
K L
M A
B
BRC
Revision: November 2009 2006 QX56
FR LH IN ABS SOL
[C1120]Circuit of front LH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
BRC-43, "
Solenoid and
VDC Change-Over Valve
System Inspection"
FR LH OUT ABS SOL
[C1121]Circuit of front LH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
RR RH IN ABS SOL
[C1126] Circuit of rear RH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
RR RH OUT ABS SOL
[C1127] Circuit of rear RH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
FR RH IN ABS SOL
[C1122] Circuit of front RH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
FR RH OUT ABS SOL
[C1123] Circuit of front RH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
RR LH IN ABS SOL
[C1124] Circuit of rear LH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
RR LH OUT ABS SOL
[C1125] Circuit of rear LH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
CV1
[C1164] Front side VDC switch-over solenoid valve (cut valve) is open or
shorted, or control line is open or shorted to power supply or
ground.
CV2
[C1165] Rear side VDC switch-over solenoid valve (cut valve) is open or
shorted, or control line is open or shorted to power supply or
ground.
SV1
[C1166] Front side VDC switch-over solenoid valve (suction valve) is
open or shorted, or control line is open or shorted to power sup-
ply or ground.
SV2
[C1167] Rear side VDC switch-over solenoid valve (suction valve) is open
or shorted, or control line is open or shorted to power supply or
ground.
PUMP MOTOR
[ C 1111 ] During actuator motor operation with ON, when actuator motor
turns OFF or when control line for actuator motor relay is open.
BRC-44, "
Actuator
Motor, Motor Relay, and
Circuit Inspection"During actuator motor operation with OFF, when actuator motor
turns ON or when control line for relay is shorted to ground.
BATTERY VOLTAGE
[ABNORMAL]
[C1109] ABS actuator and electric unit (control unit) power voltage is too
low. BRC-46, "
ABS/TCS/
VDC Control Unit Power
and Ground Systems
Inspection"
ST ANG SEN SIGNAL
[C1144]
Neutral position correction of steering angle sensor is not fin-
ished. BRC-55, "Inspection For
Self-diagnosis Result
"ST ANG SEN SIGNAL""
ST ANG SEN COM CIR
[C1156]
CAN communication line or steering angle sensor has generated
an error. BRC-40, "Steering Angle
Sensor System"
G-SENSOR
[C1113]Longitudinal G-sensor is malfunctioning, or signal line of longitu-
dinal G-sensor is open or shorted. BRC-41, "Yaw Rate/
Side/Decel G Sensor
System Inspection"
CONTROLLER FAILURE
[C1110]
Internal malfunction of ABS actuator and electric unit (control
unit) BRC-40, "ABS/TCS/
VDC Control Unit
Inspection"
CAN COMM CIRCUIT
[U1000]

CAN communication line is open or shorted.

ABS actuator and electric unit (control unit) internal malfunc-
tion

Battery voltage for ECM is suddenly interrupted for approxi-
mately 0.5 second or more.BRC-54, "
CAN Commu-
nication System Inspec-
tion" (Note 2)
SIDE G-SEN CIRCUIT
[C1146] Lateral G-sensor is malfunctioning, or signal line of lateral G-sen-
sor is open or shorted. BRC-41, "
Yaw Rate/
Side/Decel G Sensor
System Inspection"
Self-diagnostic item
Malfunction detecting condition Check system

EC-5
C
DE
F
G H
I
J
K L
M
EC A
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
C
DE
F
G H
I
J
K L
M A
EC
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-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)