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EC-448
< ECU DIAGNOSIS >[VK56DE]
ECM
AABIA0042GB
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ECM
EC-449
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AABIA0043GB
Revision: December 20092009 QX56
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EC-450
< ECU DIAGNOSIS >[VK56DE]
ECM
ABBIA0043GB
Revision: December 20092009 QX56
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ECM
EC-451
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AABIA0044GB
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EC-452
< ECU DIAGNOSIS >[VK56DE]
ECM
AABIA0045GB
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ECM
EC-453
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Fail-Safe ChartINFOID:0000000003771735
When the DTC listed below is detected, the EC
M enters fail-safe mode and the MIL lights up.
AABIA0046GB
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![INFINITI QX56 2009 Factory Service Manual
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, INFINITI QX56 2009 Factory Service Manual
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,](/manual-img/42/57031/w960_57031-1780.png)
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
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![INFINITI QX56 2009 Factory Service Manual
ECM
EC-455
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DTC Inspection Priority ChartINFOID:0000000003771736
If some DTCs are displayed at the same time, per
form inspections one by one INFINITI QX56 2009 Factory Service Manual
ECM
EC-455
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DTC Inspection Priority ChartINFOID:0000000003771736
If some DTCs are displayed at the same time, per
form inspections one by one](/manual-img/42/57031/w960_57031-1781.png)
ECM
EC-455
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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