2009 INFINITI QX56 100

EC-420
< ECU DIAGNOSIS >[VK56DE]
ECM
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
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
 Engine 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: December 20092009 QX56

ECM
EC-421
< ECU DIAGNOSIS > [VK56DE]
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*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-77
.
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 - 40,7
23 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 time ON
→ 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: December 20092009 QX56

EC-426
< ECU DIAGNOSIS >[VK56DE]
ECM
40
41
42
63Y/G
P
L
G Fuel injector No. 6
Fuel injector No. 4
Fuel injector No. 2
Fuel injector No. 8 [Engine is running]

Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14V)
45 L/Y EVAP canister purge volume
control solenoid valve [Engine is running]
 Idle speed
 Accelerator pedal: Not depressed even
slightly, after engine starting BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
 Engine speed: About 2,000 rpm (More than 100 seconds after starting engine) BATTERY VOLTAGE
(11 - 14V)
47 Y Sensor power supply
(Throttle position sensor) [Ignition switch: ON]
Approximately 5V
48 SB Sensor power supply
(EVAP control system pres-
sure sensor) [Ignition switch: ON]
Approximately 5V
49 R/Y Sensor power supply
(Refrigerant pressure sensor) [Ignition switch: ON]
Approximately 5V
50 B Throttle position sensor 1 [Ignition switch: ON]
 Engine: Stopped
 Selector lever: D
 Accelerator pedal: Fully released
More than 0.36V
[Ignition switch: ON]
 Engine: Stopped
 Selector lever: D
 Accelerator pedal: Fully depressed Less than 4.75V
TER-
MI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)SEC984C
SEC985C
SEC990C
SEC991C
Revision: December 20092009 QX56

ECM
EC-433
< ECU DIAGNOSIS > [VK56DE]
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AABWA0100GB
Revision: December 20092009 QX56

EC-454
< ECU DIAGNOSIS >[VK56DE]
ECM
 When there is an open circuit on MIL circuit, the ECM c
annot warn the driver by lighting up MIL when there
is malfunction on engine control system.
Therefore, when electrical controlled throttle and pa rt of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engi ne control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnos es except MIL circuit are detected and demands the
driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT-IIl displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-IIl display)
Just as ignition switch is turned ON
or START 40
°C (104 °F)
Approx 4 minutes or more after en-
gine starting. 80
°C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135 Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103 Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric throttle control function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric thro ttle control ac-
tuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the
engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor
The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
Revision: December 20092009 QX56

ECM
EC-455
< ECU DIAGNOSIS > [VK56DE]
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DTC Inspection Priority ChartINFOID:0000000003771736
If some DTCs are displayed at the same time, per
form inspections one by one based on the following priority
chart.
NOTE:
 If DTC U1000 and/or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-86
.
 If DTC P0607 is displayed with ot her DTC, first perform the trouble diagnosis for DTC P0607. Refer to
EC-284
.
Priority Detected items (DTC)
1  U1000 U1001 CAN communication line  P0101 P0102 P0103 Mass air flow sensor
 P0112 P0113 P0127 Intake air temperature sensor
 P0116 P0117 P0118 P0125 Engine coolant temperature sensor
 P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor
 P0128 Thermostat function
 P0181 P0182 P0183 Fuel tank temperature sensor
 P0327 P0328 P0332 P0333 Knock sensor
 P0335 Crankshaft position sensor (POS)
 P0340 Camshaft posi tion sensor (PHASE)
 P0460 P0461 P0462 P0463 Fuel level sensor
 P0500 Vehicle speed sensor
 P0605 P0607 ECM
 P0643 Sensor power supply
 P0700 TCM
 P0705 Transmission range switch
 P0850 Park/neutral position (PNP) switch
 P1550 P1551 P1552 P1553 P1554 Battery current sensor
 P1610 - P1615 NATS
 P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
Revision: December 20092009 QX56

EC-456
< ECU DIAGNOSIS >[VK56DE]
ECM
DTC Index
INFOID:0000000003771737
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
× :Applicable —: Not applicable
2  P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater
 P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
 P0075 P0081 Intake valve timing control solenoid valve
 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
 P0710 P0717 P0720 P0731 P0732 P0733 P0734 P0735 P0740 P0744 P0745 P1730 P1752 P1757 P1762 P1767
P1772 P1774 A/T related sensors, solenoid valves and switches
 P1217 Engine over temperature (OVERHEAT)
 P1140 P1145 Intake valve timing control position sensor
 P1805 Brake switch
 P2100 P2103 P2118 Electric throttle control actuator
 P2101 Electric throttle control function
3  P0011 P0021 Intake valve timing control  P0171 P0172 P0174 P0175 Fuel injection system function
 P0300 - P0308 Misfire
 P0420 P0430 Three way catalyst function
 P0442 EVAP control system (SMALL LEAK)
 P0455 EVAP control system (GROSS LEAK)
 P0456 EVAP control sys tem (VERY SMALL LEAK)
 P0506 P0507 Idle speed control system
 P1148 P1168 Closed loop control
 P1211 TCS control unit
 P1212 TCS communication line
 P1421 Cold start control
 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)
Items
(CONSULT-IIl screen terms) DTC*
1
SRT code Trip MIL
Reference
page
CONSULT-IIl
GST*
2ECM*3
CAN COMM CIRCUIT U1000 1000*5—1×EC-86
CAN COMM CIRCUIT U1001
1001*5—1 or 2*9
2*10—
EC-86
CONTROL UNIT(CAN) U1010 1010 — 1 ×EC-284
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED. P0000 0000
——
Flashing*7EC-55
INT/V TIM CONT-B1 P0011 0011 — 2 ×EC-40
INT/V TIM CONT-B2 P0021 0021 — 2 ×EC-40
A/F SEN1 HTR (B1) P0031 0031 — 2 ×EC-94
A/F SEN1 HTR (B1) P0032 0032 — 2 ×EC-94
HO2S2 HTR (B1) P0037 0037 — 2 ×EC-97
HO2S2 HTR (B1) P0038 0038 — 2 ×EC-97
A/F SEN1 HTR (B2) P0051 0051 — 2 ×EC-94
Revision: December 20092009 QX56

ECM
EC-457
< ECU DIAGNOSIS > [VK56DE]
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OA/F SEN1 HTR (B2) P0052 0052 — 2
×EC-94
HO2S2 HTR (B2) P0057 0057 — 2 ×EC-97
HO2S2 HTR (B2) P0058 0058 — 2 ×EC-97
INT/V TIM V/CIR-B1 P0075 0075 — 2 ×EC-100
INT/V TIM V/CIR-B2 P0081 0081 — 2 ×EC-100
MAF SEN/CIRCUIT-B1 P0101 0101 — 2 ×EC-103
MAF SEN/CIRCUIT-B1 P0102 0102 — 1 ×EC-109
MAF SEN/CIRCUIT-B1 P0103 0103 — 1 ×EC-109
IAT SEN/CIRCUIT-B1 P0112 0112 — 2 ×EC-114
IAT SEN/CIRCUIT-B1 P0113 0113 — 2 ×EC-114
ECT SEN/CIRC P0116 0116 — 2 ×EC-117
ECT SEN/CIRC P0117 0117 — 1 ×EC-120
ECT SEN/CIRC P0118 0118 — 1 ×EC-120
TP SEN 2/CIRC-B1 P0122 0122 — 1 ×EC-124
TP SEN 2/CIRC-B1 P0123 0123 — 1 ×EC-124
ECT SENSOR P0125 0125 — 2 ×EC-128
IAT SENSOR-B1 P0127 0127 — 2 ×EC-131
THERMSTAT FNCTN P0128 0128 — 2 ×EC-134
A/F SENSOR1 (B1) P0130 0130 — 2 ×EC-136
A/F SENSOR1 (B1) P0131 0131 — 2 ×EC-140
A/F SENSOR1 (B1) P0132 0132 — 2 ×EC-143
A/F SENSOR1 (B1) P0133 0133 ×2 ×EC-146
HO2S2 (B1) P0137 0137 ×2 ×EC-152
HO2S2 (B1) P0138 0138 ×2 ×EC-157
HO2S2 (B1) P0139 0139 ×2 ×EC-164
A/F SENSOR1 (B2) P0150 0150 — 2 ×EC-136
A/F SENSOR1 (B2) P0151 0151 — 2 ×EC-140
A/F SENSOR1 (B2) P0152 0152 — 2 ×EC-143
A/F SENSOR1 (B2) P0153 0153 ×2 ×EC-146
HO2S2 (B2) P0157 0157 ×2 ×EC-152
HO2S2 (B2) P0158 0158 ×2 ×EC-157
HO2S2 (B2) P0159 0159 ×2 ×EC-164
FUEL SYS-LEAN-B 1 P0171 0171 — 2 ×EC-169
FUEL SYS-RICH-B1 P0172 0172 — 2 ×EC-174
FUEL SYS-LEAN-B 2 P0174 0174 — 2 ×EC-169
FUEL SYS-RICH-B2 P0175 0175 — 2 ×EC-174
FTT SENSOR P0181 0181 — 2 ×EC-179
FTT SEN/CIRCUIT P0182 0182 — 2 ×EC-182
FTT SEN/CIRCUIT P0183 0183 — 2 ×EC-182
TP SEN 1/CIRC-B1 P0222 0222 — 1 ×EC-185
TP SEN 1/CIRC-B1 P0223 0223 — 1 ×EC-185
MULTI CYL MISFIRE P0300 0300 — 2 ×EC-189
Items
(CONSULT-IIl screen terms) DTC*
1
SRT code Trip MIL
Reference
page
CONSULT-IIl
GST*
2ECM*3
Revision: December 20092009 QX56