2007 INFINITI QX56 ignition

EC-124
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
5. Perform each diagnostic service according to each service pro-
cedure.
For further information, see the GST Operation Manual of
the tool maker.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531628
Remarks:
l Specification data are reference values.
l Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data in spite of the
ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the ECM according to the signals
input from the camshaft position sensor and other ignition timing related sensors.
SEF416S
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED• Run engine and compare CONSULT-II value with the tachometer indica-
tion.Almost the same speed as the
tachometer indication.
MAS A/F SE-B1 See EC-129
.
B/FUEL SCHDL See EC-129
.
A/F ALPHA-B1
A/F ALPHA-B2See EC-129
.
COOLAN TEMP/S • Engine: After warming up More than 70°C (158°F)
A/F SEN1 (B1)
A/F SEN1 (B2)• Engine: After warming up Maintaining engine speed at 2,000 rpm Fluctuates around 2.2 V
HO2S2 (B1)
HO2S2 (B2)• Revving engine from idle to 3,000 rpm quickly 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 load0 - 0.3V ←→ Approx. 0.6 - 1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)• Revving engine from idle to 3,000 rpm quickly 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 loadLEAN ←→ RICH
VHCL SPEED SE• Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
BATTERY VOLT • Ignition switch: ON (Engine stopped) 11 - 14V
ACCEL SEN 1• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*
1• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
THRTL SEN 1
THRTL SEN 2*
2
• Ignition switch: ON
(Engine stopped)
• Selector lever: DAccelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
EVAP SYS PRES • Ignition switch: ON Approx. 1.8 - 4.8V
START SIGNAL • Ignition switch: ON → START → ON OFF → ON → OFF
CLSD THL POS• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF

TROUBLE DIAGNOSIS
EC-125
< SERVICE INFORMATION >
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AIR COND SIG• Engine: After warming up, idle the
engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
P/N POSI SW • Ignition switch: ONSelector lever: P or N ON
Selector lever: Except above OFF
PW/ST SIGNAL• Engine: After warming up, idle the
engineSteering wheel: Not being turned
(Forward direction)OFF
Steering wheel: Being turned ON
LOAD SIGNAL • Ignition switch: ONRear window defogger switch is ON
and/or lighting switch is in 2nd.ON
Rear window defogger switch is OFF
and lighting switch is OFF.OFF
IGNITION SW • Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW• Engine: After warming up, idle the
engineHeater fan control switch: ON ON
Heater fan control switch: OFF OFF
BRAKE SW • Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No loadIdle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No loadIdle 10° - 20° BTDC
2,000 rpm 25° - 45° BTDC
CAL/LD VALUE• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No loadIdle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No loadIdle 3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
PURG VOL C/V• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No loadIdle
(Accelerator pedal: Not depressed
even slightly, after engine starting.)0%
2,000 rpm —
INT/V TIM (B1)
INT/V TIM (B2)• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No loadIdle−5° - 5°CA
2,000 rpm Approx. 0° - 20°CA
INT/V SOL (B1)
INT/V SOL (B2)• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No loadIdle 0% - 2%
2,000 rpm Approx. 25% - 50%
AIR COND RLY• Engine: After warming up, idle the
engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor: Operates)ON
FUEL PUMP RLY• For 1 second after turning ignition switch ON
• Engine running or crankingON
• Except above conditions OFF
VENT CONT/V • Ignition switch: ON OFF
THRTL RELAY • Ignition switch: ON ONMONITOR ITEM CONDITION SPECIFICATION

EC-126
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
COOLING FAN• Engine: After warming up, idle the
engine
• Air conditioner switch: OFFEngine coolant temperature: 99°C
(210°F) or lessOFF
Engine coolant temperature: 100°C
(212°F) or moreHI
HO2S2 HTR (B1)
HO2S2 HTR (B2)• 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 loadON
• Engine speed: Above 3,600 rpm OFF
I/P PULLY SPD • Vehicle speed: More than 20 km/h (12 MPH)Almost the same speed as the
tachometer indication
VEHICLE SPEED• Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
TRVL AFTER MIL • Ignition switch: ONVehicle has traveled after MIL has
turned ON.0 - 65,535 km
(0 - 40,723 mile)
A/F S1 HTR (B1)
A/F S1 HTR (B2)• Engine: After warming up, idle the engine 4 - 100%
AC PRESS SEN• Engine: Idle
• Both A/C switch and blower fan switch: ON (Compressor operates.)1.0 - 4.0V
VHCL SPEED SE• Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
SET VHCL SPD • Engine: Running ASCD: Operating.The preset vehicle speed is dis-
played.
MAIN SW • Ignition switch: ONMAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW • Ignition switch: ONCANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW • Ignition switch: ONRESUME/ACCELERATE switch:
PressedON
RESUME/ACCELERATE switch: Re-
leasedOFF
SET SW • Ignition switch: ONSET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DIST SW • Ignition switch: ONDISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
BRAKE SW1 • Ignition switch: ONBrake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2 • Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP • Ignition switch: ONMAIN switch: Pressed at the 1st time
→ at the 2nd timeON → OFF
SET LAMP• MAIN switch: ON
• Vehicle speed: Between 40 km/h
(25 MPH) and 144 km/h (89
MPH)ASCD: Operating ON
ASCD: Not operating OFF
ALT DUTY • Engine: Idle 0 - 80%
BAT CUR SEN• Engine speed: Idle
• Battery: Fully charged*
2
• Selector lever: P or N
• Air conditioner switch: OFF
•No loadApprox. 2,600 - 3,500mV MONITOR ITEM CONDITION SPECIFICATION

TROUBLE DIAGNOSIS
EC-127
< SERVICE INFORMATION >
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from ECM terminals voltage signal.
*2: Before measuring the terminal voltage, confirm the battery is fully charged. Refer to SC-4
.
Major Sensor Reference Graph in Data Monitor ModeINFOID:0000000003531629
The following are the major sensor reference graphs in “DATA MONITOR” mode.
CLSD THL POS, ACCEL SEN 1, THRTL SEN 1
Below is the data for “CLSD THL POS”, “ACCEL SEN 1” and “THRTL SEN 1” when depressing the accelera-
tor pedal with the ignition switch ON and with selector lever in D position.
The signal of “ACCEL SEN 1” and “THRTL SEN 1” should rise gradually without any intermittent drop or rise
after “CLSD THL POS” is changed from ON to OFF.
ENG SPEED, MAS A/F SE-B1, THRTL SEN 1, HO2S2 (B1), INJ PULSE-B1
Below is the data for “ENG SPEED”, “MAS A/F SE-B1”, “THRTL SEN 1”, “HO2S2 (B1)” and “INJ PULSE-B1”
when revving engine quickly up to 4,800 rpm under no load after warming up engine sufficiently.
Each value is for reference, the exact value may vary.
ALT DUTY SIG• Power generation voltage variable control: Operating ON
• Power generation voltage variable control: Not operating OFF MONITOR ITEM CONDITION SPECIFICATION
PBIB0198E
PBIB2445E

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-133
< SERVICE INFORMATION >
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6.CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-80, "
Fuel Pressure Check" .)
OK or NG
OK >> GO TO 9.
NG (Fuel pressure is too high)>>Replace fuel pressure regulator, refer to EC-80, "
Fuel Pressure Check" .
GO TO 8.
NG (Fuel pressure is too low)>>GO TO 7.
7.DETECT MALFUNCTIONING PART
1. Check the following.
- Clogged and bent fuel hose and fuel tube
- Clogged fuel filter
- Fuel pump and its circuit (Refer to EC-613
.)
2. If NG, repair or replace the malfunctioning part. (Refer to EC-80, "
Fuel Pressure Check" .)
If OK, replace fuel pressure regulator.
>> GO TO 8.
8.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 >> GO TO 9.
9.PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine
speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10.DETECT MALFUNCTIONING PART
1. Check the following.
- Ignition coil and its circuit (Refer to EC-626
.)
- Fuel injector and its circuit (Refer to EC-608
.)
- Intake air leakage
- Low compression pressure (Refer to EM-64, "
On-Vehicle Service".)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caused by leakage from fuel injector or clogging.)
>> GO TO 11.
11 .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 >> GO TO 12.
PBIB0133E

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-135
< SERVICE INFORMATION >
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- 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.
20.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG (“B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value)>>GO TO 21.
21.DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.
22.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 >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-194 .
2. GO TO 29.
NG >> GO TO 23.
23.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace mass air flow sensor, and
then GO TO 29.
24.REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to
BL-117, "
ECM Re-communicating Function".
PBIB2370E

EC-140
< SERVICE INFORMATION >
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis Procedure
INFOID:0000000003531637
1.INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Ye s > > G O T O 8 .
No >> GO TO 2.
2.CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 109 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• 10A fuse
• Harness for open or short between ECM and fuse
>> Repair harness or connectors.
4.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 B ECM ground[Engine is running]
• Idle speedBody ground
109 L/W Ignition switch[Ignition switch: OFF]0V
[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]
• More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 5
11 6B
B/WECM ground[Engine is running]
• Idle speedBody ground
11 9
120BR
BRPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0015E

POWER SUPPLY AND GROUND CIRCUIT
EC-141
< SERVICE INFORMATION >
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Refer to EC-143, "Ground Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace ground connections.
5.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors F32, E2
• Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
7.CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> Go to EC-626 .
NG >> GO TO 8.
8.CHECK ECM POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and then OFF.
BBIA0354E
Continuity should exist.
Voltage: Battery voltage
PBIB2063E