2010 INFINITI QX56 ecm

EC-420
< COMPONENT DIAGNOSIS >[VK56DE]
REFRIGERANT PRESSURE SENSOR
Refer to EC-85, "Ground Inspection".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3.CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect refrigerant pressure sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between refrigerant pressure sensor terminal 1 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E5, F14
• Harness for open or short between ECM and refrigerant pressure sensor
>> Repair harness or connectors.
5.CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between refrigerant pressure sensor terminal 3 and ECM terminal 67. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
BBIA0354E
BBIA0445E
Voltage: Approximately 5 V
PBIB0188E
Continuity should exist.
Revision: April 20092010 QX56

REFRIGERANT PRESSURE SENSOREC-421
< COMPONENT DIAGNOSIS > [VK56DE]
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6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E5, F14
• Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK REFRIGERANT PRESSURE SENSOR IN PUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 70 and refrigerant pressure sensor terminal 2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E5, F14
• Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
OK or NG
OK >> Replace refrigerant pressure sensor.
NG >> Repair or replace. Continuity should exist.
Revision: April 20092010 QX56

EC-422
< ECU DIAGNOSIS >[VK56DE]
ECM
ECU DIAGNOSIS
ECM
CONSULT-lll Reference Valu
e in Data Monitor ModeINFOID:0000000005149492
Remarks:
z Specification data are reference values.
z Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly relate d 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 moni tors the data calculated by the ECM according to the signals
input from the camshaft position sensor and other ignition timing related sensors.
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED • Run engine and compare CONSULT-IIl value with the tachometer indica-
tion. Almost the same speed as the
tachometer indication.
MAS A/F SE-B1 See EC-74
.
B/FUEL SCHDL See EC-74
.
A/F ALPHA-B1
A/F ALPHA-B2 See
EC-74
.
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 load 0 - 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 load LEAN
←→ RICH
VHCL SPEED SE • Turn drive wheels and compare CONSULT-IIl 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
TP SEN 1-B1
TP SEN 2-B1 • Ignition switch: ON
(Engine stopped)
• Selector lever: D Accelerator 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
AIR COND SIG • Engine: After warming up, idle the
engine Air conditioner switch: OFF
OFF
Air conditioner switch: ON
(Compressor operates.) ON
P/N POSI SW • Ignition switch: ON Selector lever: P or N
ON
Selector lever: Except above OFF
PW/ST SIGNAL • Engine: After warming up, idle the
engine Steering wheel: Not being turned
(Forward direction)
OFF
Steering wheel: Being turned ON
Revision: April 20092010 QX56

ECM
EC-423
< ECU DIAGNOSIS > [VK56DE]
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LOAD SIGNAL • Ignition switch: ON
Rear 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
engine Heater fan control switch: ON ON
Heater fan control switch: OFF OFF
BRAKE SW • Ignition switch: ON Brake 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 load Idle
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 load Idle
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 load Idle
14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW • Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load Idle
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 load Idle
(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 load Idle
−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 load Idle
0% - 2%
2,000 rpm Approx. 25% - 50%
AIR COND RLY • Engine: After warming up, idle the
engine Air conditioner switch: OFF
OFF
Air conditioner switch: ON
(Compressor: Operates) ON
FUEL PUMP RLY • For 1 second after turning ignition switch ON
•
E

ngine running or cranking ON
• Except above conditions OFF
VENT CONT/V • Ignition switch: ON OFF
THRTL RELAY • Ignition switch: ON ON
COOLING FAN • Engine: After warming up, idle the
engine
• Air conditioner switch: OFF Engine coolant temperature: 99
°C
(210 °F) or less OFF
Engine coolant temperature: 100 °C
(212 °F) or more HI
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 load ON
• Engine speed: Above 3,600 rpm OFF
MONITOR ITEM
CONDITION SPECIFICATION
Revision: April 20092010 QX56

EC-424
< ECU DIAGNOSIS >[VK56DE]
ECM
*1: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, the
y differ
from ECM terminals voltage signal.
*2: Before measuring the terminal voltage, confirm the battery is fully charged. Refer to PG-74
.
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-IIl value with the speedometer
indication. Almost the same speed as the
speedometer indication
TRVL AFTER MIL • Ignition switch: ON Vehicle 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-IIl 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: ON MAIN switch: Pressed
ON
MAIN switch: Released OFF
CANCEL SW • Ignition switch: ON CANCEL switch: Pressed
ON
CANCEL switch: Released OFF
RESUME/ACC SW • Ignition switch: ON RESUME/ACCELERATE switch:
Pressed
ON
RESUME/ACCELERATE switch: Re-
leased OFF
SET SW • Ignition switch: ON SET/COAST switch: Pressed
ON
SET/COAST switch: Released OFF
DIST SW • Ignition switch: ON DISTANCE switch: Pressed
ON
DISTANCE switch: Released OFF
BRAKE SW1 • Ignition switch: ON Brake pedal: Fully released
ON
Brake pedal: Slightly depressed OFF
BRAKE SW2 • Ignition switch: ON Brake pedal: Fully released
OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP • Ignition switch: ON MAIN 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 load Approx. 2,600 - 3,500mV
ALT DUTY SIG • Power generation voltage variable control: Operating
ON
• Power generation voltage variable control: Not operating OFF
MONITOR ITEM
CONDITION SPECIFICATION
Revision: April 20092010 QX56

ECM
EC-425
< ECU DIAGNOSIS > [VK56DE]
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ECM Harness Connector Terminal LayoutINFOID:0000000005149493
ECM Terminal and Reference ValueINFOID:0000000005149494
PREPARATION
ECM is located in the engine room passenger side behind battery.
ECM INSPECTION TABLE
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-IIl.
CAUTION:
Do not use ECM ground terminals wh
en measuring input/output voltage. Doing so may result in dam-
age to the ECMs transistor. Use a ground ot her than ECM terminals, such as the ground.
PBIB3368E
BBIA0386E
TER-
MI-
NAL
NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
1 B ECM ground [Engine is running]
• Idle speedBody ground
2 LG/B A/F sensor 1 heater (bank 1) [Engine is running]
•
Warm-up condition
• Idle speed (More than 140 seconds after starting en-
gine) Approximately 2.9 - 8.8V
3L Throttle contro
l motor relay
power supply [Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle cont rol motor (Close)[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Fully released 0 - 14V
PBIA8148J
PBIB1104E
Revision: April 20092010 QX56

EC-426
< ECU DIAGNOSIS >[VK56DE]
ECM
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 heat-
er (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)
10 W Intake valve timing control so-
lenoid valve (bank 1) [Engine is running]
•
Warm-up condition
• Idle speed BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
• Warm-up condition
• Engine speed: 2,000rpm 7 - 12V
11 L G Intake valve timing control so-
lenoid valve (bank 2) [Engine is running]
•
Warm-up condition
• Idle speed BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
• Warm-up condition
• Engine speed: 2,000rpm 7 - 12V
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
TER-
MI-
NAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
PBIB1105E
PBIB1790E
PBIB1790E
Revision: April 20092010 QX56

ECM
EC-427
< ECU DIAGNOSIS > [VK56DE]
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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
14 Y Camshaft position sensor
(PHASE) [Engine is running]
•
Warm-up condition
• Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle 1.0 - 4.0V
[Engine is running]
• Engine speed: 2,000 rpm 1.0 - 4.0V
15 W Knock sensor (bank 1) [Engine is running]
• Idle speedApproximately 2.5V
16 G A/F sensor 1 (bank 1) [Engine is running]
•
Warm-up condition
• Engine speed: 2,000 rpm Approximately 1.8V
Output voltage varies with air fuel
ratio.
TER-
MI-
NAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)PBIB1041E
PBIB1042E
PBIB1039E
PBIB1040E
Revision: April 20092010 QX56