2007 INFINITI QX56 ECO mode

EC-420
< SERVICE INFORMATION >
DTC P0456 EVAP CONTROL SYSTEM
2. Does water drain from the EVAP canister?
Ye s o r N o
Yes >> GO TO 10.
No (With CONSULT-II)>>GO TO 12.
No (Without CONSULT-II)>>GO TO 13.
10.CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK (With CONSULT-II)>>GO TO 12.
OK (Without CONSULT-II)>>GO TO 13.
NG >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check the following.
• EVAP canister for damage
• EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
12.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-II
1. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
2. Start engine.
3. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode.
4. Touch “Qu” on CONSULT-II screen to increase “PURG VOL
CONT/V” opening to 100%.
5. Check vacuum hose for vacuum when revving engine up to
2,000 rpm.
OK or NG
OK >> GO TO 15.
NG >> GO TO 14.
13.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
OK or NG
OK >> GO TO 16.
NG >> GO TO 14.
14.CHECK VACUUM HOSE
BBIA0351E
Vacuum should exist.
PBIB1678E
Vacuum should exist.

DTC P0460 FUEL LEVEL SENSOR
EC-423
< SERVICE INFORMATION >
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DTC P0460 FUEL LEVEL SENSOR
Component DescriptionINFOID:0000000003531916
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis LogicINFOID:0000000003531917
NOTE:
•If DTC P0460 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-145
.
•If DTC P0460 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer
to EC-147
.
When the vehicle is parked, naturally the fuel level in the fuel tank is stable. It means that output signal of the
fuel level sensor does not change. If ECM senses sloshing signal from the sensor, fuel level sensor malfunc-
tion is detected.
DTC Confirmation ProcedureINFOID:0000000003531918
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and wait maximum of 2 consecutive minutes.
4. If 1st trip DTC is detected, go to EC-424, "
Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0460
0460Fuel level sensor circuit
noiseEven though the vehicle is parked, a signal be-
ing varied is sent from the fuel level sensor to
ECM.• Harness or connectors
(The CAN communication line is open or
shorted)
• Harness or connectors
(The sensor circuit is open or shorted)
• Combination meter
• Fuel level sensor
SEF195Y

DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
EC-427
< SERVICE INFORMATION >
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DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
Component DescriptionINFOID:0000000003531926
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis LogicINFOID:0000000003531927
NOTE:
•If DTC P0462 or P0463 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for
DTC U1000, U1001. Refer to EC-145
.
•If DTC P0462 or P0463 is displayed with DTC U1010, first perform the trouble diagnosis for DTC
U1010. Refer to EC-147
.
This diagnosis indicates the former, to detect open or short circuit malfunction.
DTC Confirmation ProcedureINFOID:0000000003531928
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at ignition
switch ON.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-428, "
Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0462
0462Fuel level sensor circuit
low inputAn excessively low voltage from the sensor is
sent to ECM.• Harness or connectors
(The CAN communication line is open or
shorted)
• Harness or connectors
(The sensor circuit is open or shorted)
• Combination meter
• Fuel level sensor P0463
0463Fuel level sensor circuit
high inputAn excessively high voltage from the sensor is
sent to ECM.
SEF195Y

DTC P0500 VSS
EC-429
< SERVICE INFORMATION >
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DTC P0500 VSS
DescriptionINFOID:0000000003531931
NOTE:
•If DTC P0500 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-145
.
•If DTC P0500 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer
to EC-147
.
The vehicle speed signal is sent to the combination meter from the “ABS actuator and electric unit (control
unit)” by CAN communication line. The c combination meter then sends a signal to the ECM by CAN commu-
nication line.
On Board Diagnosis LogicINFOID:0000000003531932
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureINFOID:0000000003531933
CAUTION:
Always drive vehicle at a safe speed.
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.
TESTING CONDITION:
Steps 1 and 2 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Read “VHCL SPEED SE” in “DATA MONITOR” mode with CONSULT-II. The vehicle speed on CONSULT-
II should exceed 10 km/h (6 MPH) when rotating wheels with suitable gear position.
If NG, go to EC-430, "
Diagnosis Procedure".
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Warm engine up to normal operating temperature.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0500
0500Vehicle speed sensorThe almost 0 km/h (0 MPH) signal from
vehicle speed sensor is sent to ECM even
when vehicle is being driven.• Harness or connectors
(The CAN communication line is open or short-
ed)
• Harness or connectors
(The vehicle speed signal circuit is open or
shorted)
• Wheel sensor
• Combination meter
• ABS actuator and electric unit (control unit)
Detected items Engine operating condition in fail-safe mode
Vehicle speed sensorWhen the fail-safe system for vehicle speed sensor is activated, the cooling fan operates (High) while
engine is running.

DTC P0506 ISC SYSTEM
EC-431
< SERVICE INFORMATION >
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DTC P0506 ISC SYSTEM
DescriptionINFOID:0000000003531936
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 LogicINFOID:0000000003531937
DTC Confirmation ProcedureINFOID:0000000003531938
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-645
.
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-431, "
Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003531939
1.CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0506
0506Idle speed control system
RPM lower than expectedThe idle speed is less than the target idle speed
by 100 rpm or more.• Electric throttle control actuator
• Intake air leak
SEF174Y

DTC P0507 ISC SYSTEM
EC-433
< SERVICE INFORMATION >
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DTC P0507 ISC SYSTEM
DescriptionINFOID:0000000003531940
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 LogicINFOID:0000000003531941
DTC Confirmation ProcedureINFOID:0000000003531942
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-645
.
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-433, "
Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003531943
1.CHECK PCV HOSE CONNECTION
Confirm that PCV hose is connected correctly.
OK or NG
OK >> GO TO 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0507
0507Idle speed control system
RPM higher than expectedThe idle speed is more than the target idle
speed by 200 rpm or more.• Electric throttle control actuator
• Intake air leak
• PCV system
SEF174Y

DTC P0550 PSP SENSOR
EC-435
< SERVICE INFORMATION >
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DTC P0550 PSP SENSOR
Component DescriptionINFOID:0000000003531944
Power steering pressure (PSP) sensor (1) is installed to the power
steering high-pressure tube and detects a power steering load. This
sensor is a potentiometer which transforms the power steering load
into output voltage, and emits the voltage signal to the ECM. The
ECM controls the electric throttle control actuator and adjusts the
throttle valve opening angle to increase the engine speed and
adjusts the idle speed for the increased load.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531945
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531946
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-447
.
DTC Confirmation ProcedureINFOID:0000000003531947
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-437, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0741E
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL• Engine: After warming up, idle the
engineSteering wheel: Not being turned
(Forward direction)OFF
Steering wheel: Being turned ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550
0550Power steering pressure
sensor circuitAn excessively low or high voltage from the
sensor is sent to ECM.• Harness or connectors
(The sensor circuit is open or shorted)
• Power steering pressure sensor
SEF058Y

EC-440
< SERVICE INFORMATION >
DTC P0603 ECM POWER SUPPLY
DTC P0603 ECM POWER SUPPLY
Component DescriptionINFOID:0000000003531952
Battery voltage is supplied to the ECM even when the ignition switch
is turned OFF for the ECM memory function of the DTC memory, the
air-fuel ratio feedback compensation value memory, the idle air vol-
ume learning value memory, etc.
On Board Diagnosis LogicINFOID:0000000003531953
DTC Confirmation ProcedureINFOID:0000000003531954
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.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
5. Repeat steps 3 and 4 for 4 times.
6. If 1st trip DTC is detected, go to EC-442, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0603
0603ECM power supply circuitECM back-up RAM system does not function
properly.• Harness or connectors
[ECM power supply (back-up) circuit is
open or shorted.]
•ECM
SEF058Y