2006 INFINITI QX56 power steering

TROUBLE DIAGNOSISEC-93
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Revision: November 2009 2006 QX56
1 - 6: The numbers refer to the order of inspection.
(continued on next page)Vehicle speed signal circuit
2 3 33EC-442
Power steering pressure sensor circuit 23 3 EC-448
ECM 22333333333 EC-453,
EC-457
Park/Neutral position (PNP) switch circuit 3 3 3 33EC-465
Refrigerant pressure sensor circuit 233 4 EC-630
Electrical load signal circuit 3EC-596
Air conditioner circuit 223333333 3 2 AT C - 3 4
ABS actuator and electric unit (control unit)4EC-471
,
EC-472

or BRC-11
SYMPTOM
Refer-
ence 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

EC-106Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
3LThrottle control motor relay
power supply [Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close) [Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully released0 - 14V
5 L/B Throttle control motor (Open) [Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully depressed0 - 14V
6GR Heated oxygen sensor 2
heater (bank 1) [Engine is running]

Engine speed: Below 3,600 rpm after the
following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - 1.0V
[Ignition switch: ON]

Engine: Stopped
[Engine is running]

Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14V)
12 R Power steering pressure sen-
sor [Engine is running]

Steering wheel: Being turned
0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned 0.4 - 0.8V
13 O Crankshaft position sensor
(POS) [Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle Approximately 10V
[Engine is running]

Engine speed: 2,000 rpm Approximately 10V
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
PBIB1104E
PBIB1105E
PBIB1041E
PBIB1042E

TROUBLE DIAGNOSISEC-111
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Revision: November 2009 2006 QX5682 B/RSensor ground
(APP sensor 1) [Engine is running]
Warm-up condition

Idle speed
Approximately 0V
83 G/W Sensor ground
(APP sensor 2) [Engine is running]

Warm-up condition

Idle speed
Approximately 0V
85 G/W Data link connector [Ignition switch: ON]

CONSULT-II or GST: DisconnectedApproximately 5V - Battery volt-
age (11 - 14V)
86 P CAN communication line [Ignition switch: ON]Approximately 1.1 - 2.3V
Output voltage varies with the
communication status
90 L Sensor power supply
(APP sensor 1) [Ignition switch: ON]
Approximately 5V
91 W/R Sensor power supply
(APP sensor 2) [Ignition switch: ON]
Approximately 5V
94 L CAN communication line [Ignition switch: ON]Approximately 2.6 - 3.2V
Output voltage varies with the
communication status.
98 G/R Accelerator pedal position
sensor 2 [Ignition switch: ON]

Engine: Stopped

Accelerator pedal: Fully released
0.25 - 0.50V
[Ignition switch: ON]

Engine: Stopped

Accelerator pedal: Fully depressed 2.0 - 2.5V
99 G/Y ASCD steering switch
(Models with ICC system) [Ignition switch: ON]

ICC steering switch: OFF
Approximately 4.3V
[Ignition switch: ON]

MAIN switch: Pressed Approximately 0V
[Ignition switch: ON]

CANCEL switch: Pressed Approximately 1.3V
[Ignition switch: ON]

RESUME/ACCELERATE switch: Pressed Approximately 3.7V
[Ignition switch: ON]

SET/COAST switch: Pressed Approximately 3V
[Ignition switch: ON]

DISTANCE switch: Pressed Approximately 2.2V
99 G/Y 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
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)

TROUBLE DIAGNOSISEC-115
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Revision: November 2009 2006 QX56
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI- TOR DATA
MONI- TOR
(SPEC) ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS) ××××
Camshaft position sensor (PHASE) ××××
Mass air flow sensor ×××
Engine coolant temperature sensor ×××××
Air fuel ratio (A/F) sensor 1 ×××× ×
Heated oxygen sensor 2 ×××× ×
Wheel sensor ××××
Accelerator pedal position sensor ×××
Throttle position sensor ××××
Fuel tank temperature sensor ××××
EVAP control system pressure
sensor ××
×
Intake air temperature sensor ××××
Knock sensor ×
Refrigerant pressure sensor ××
Closed throttle position switch
(accelerator pedal position sensor
signal) ××
Air conditioner switch ××
Park/neutral position (PNP) switch ×××
Stop lamp switch ×××
Power steering pressure sensor ×××
Battery voltage ××
Load signal ××
Fuel level sensor ×××
ICC steering switch ×××
ASCD steering switch ×××
ICC brake switch ×××
ASCD brake switch ×××

EC-120Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
FUEL LEVEL SE
[V]×
The signal voltage of the fuel level sen-
sor is displayed.
START SIGNAL
[ON/OFF] ××

Indicates start signal status [ON/OFF]
computed by the ECM according to the
signals of engine speed and battery volt-
age.

After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF] ××

Indicates idle position [ON/OFF] com-
puted by ECM according to the acceler-
ator pedal position sensor signal.
AIR COND SIG
[ON/OFF] ××

Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF] ××

Indicates [ON/OFF] condition from the
park/neutral position (PNP) switch sig-
nal.
PW/ST SIGNAL
[ON/OFF] ××

[ON/OFF] condition of the power steer-
ing system (determined by the signal
voltage of the power steering pressure
sensor signal) is indicated.
LOAD SIGNAL
[ON/OFF] ××

Indicates [ON/OFF] condition from the
electrical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
IGNITION SW
[ON/OFF] ×

Indicates [ON/OFF] condition from igni-
tion switch signal.
HEATER FAN SW
[ON/OFF] ×

Indicates [ON/OFF] condition from
heater fan switch signal.
BRAKE SW
[ON/OFF] ×

Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec] ×

Indicates the actual fuel injection pulse
width compensated by ECM according
to the input signals.
When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING
[BTDC] ×

Indicates the ignition timing computed
by ECM according to the input signals.
When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE [%]

“ Calculated load value ” indicates the
value of the current air flow divided by
peak air flow.
MASS AIRFLOW
[g ·m/s]

Indicates the mass air flow computed by
ECM according to the signal voltage of
the mass air flow sensor.
PURG VOL C/V [%]

Indicates the EVAP canister purge vol-
ume control solenoid valve control value
computed by the ECM according to the
input signals.

The opening becomes larger as the
value increases.
AIR COND RLY
[ON/OFF] ×

The air conditioner relay control condi-
tion (determined by ECM according to
the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF] ×

Indicates the fuel pump relay control
condition determined by ECM according
to the input signals.
Monitored item
[Unit] ECM
INPUT
SIGNALS MAIN
SIGNALS Description Remarks

EC-140Revision: November 2009
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2006 QX56
16. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1 ”, “A/F ALPHA-B2 ” in “DATA MONITOR (SPEC) ” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-92, "
Symptom Matrix Chart" .
17. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL ” in “DATA MONITOR (SPEC) ” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18. DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
–Engine oil level is too high
–Engine oil viscosity
–Belt tension of power steering, alternator, A/C compressor, etc. is excessive
–Noise from engine
–Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
–Valve clearance malfunction
–Intake valve timing control function malfunction
–Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19. CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
PBIB2332E

EC-444Revision: November 2009
DTC P0506 ISC SYSTEM
2006 QX56
DTC P0506 ISC SYSTEMPFP:23781
DescriptionUBS00H6H
NOTE:
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicUBS00H6I
DTC Confirmation ProcedureUBS00H6J
NOTE:

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.

If the target idle speed is out of the specified value, perform EC-78, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-637,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

Always perform the test at a temperature above −10 °C (14 °F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR”
mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-445, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0506
0506 Idle speed control system
RPM lower than expected The idle speed is less than the target idle
speed by 100 rpm or more.

Electric throttle control actuator

Intake air leak
SEF174Y

EC-446Revision: November 2009
DTC P0507 ISC SYSTEM
2006 QX56
DTC P0507 ISC SYSTEMPFP:23781
DescriptionUBS00H6L
NOTE:
If DTC P0507 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicUBS00H6M
DTC Confirmation ProcedureUBS00H6N
NOTE:

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.

If the target idle speed is out of the specified value, perform EC-78, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-637,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

Always perform the test at a temperature above −10 °C (14 °F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR”
mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-447, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0507
0507 Idle speed control system
RPM higher than expected The idle speed is more than the target idle
speed by 200 rpm or more.

Electric throttle control actuator

Intake air leak

PCV system
SEF174Y