2008 INFINITI QX56 ECU

P0456 EVAP CONTROL SYSTEMEC-269
< COMPONENT DIAGNOSIS > [VK56DE]
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5.INSTALL THE PRESSURE PUMP
To locate the EVAP leak, install EVAP service port adapter and pres-
sure pump to EVAP service port securely.
NOTE:
Improper installation of the EV AP service port adapter to the
EVAP service port may cause leaking.
With CONSULT-III>>GO TO 6.
Without CONSULT-III>>GO TO 7.
6.CHECK FOR EVAP LEAK
With CONSULT-III
1. Turn ignition switch ON.
2. Select “EVAP SYSTEM CLOSE” of “WORK SUPPORT” mode with CONSULT-III.
3. Touch “START” and apply pressure into the EVAP line until the pressure indicator reaches the middle of the bar graph.
CAUTION:
• Do not use compressed air or a high pressure pump.
• Do not exceed 4.12 kPa (0.042 kg/cm
2 , 0.6 psi) of pressure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details.
Refer to EC-37, "
Description" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace.
7.CHECK FOR EVAP LEAK
Without CONSULT-III
1. Turn ignition switch OFF.
BBIA0366E
SEF916U
SEF200U
Revision: March 2010 2008 QX56

EC-274
< COMPONENT DIAGNOSIS >[VK56DE]
P0460 FUEL LEVEL SENSOR
P0460 FUEL LEVEL SENSOR
Component DescriptionINFOID:0000000001351639
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 Diagn
osis LogicINFOID:0000000001351640
NOTE:
•If DTC P0460 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-87
.
• If DTC P0460 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer
to EC-88
.
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 sloshi ng signal from the sensor, fuel level sensor malfunc-
tion is detected.
DTC Confirmation ProcedureINFOID:0000000001351641
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-III
1. Start engine and wait maximum of 2 consecutive minutes.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-274, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351642
1.CHECK COMBINATION METER FUNCTION
Refer to MWI-5, "
METER SYSTEM : System Description".
OK or NG
OK >> GO TO 2.
NG >> Go to MWI-34, "
Component Inspection".
2.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0460
0460 Fuel level sensor circuit
noise Even 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
Revision: March 2010 2008 QX56

EC-280
< COMPONENT DIAGNOSIS >[VK56DE]
P0500 VSS
P0500 VSS
DescriptionINFOID:0000000001351654
NOTE:
•
If DTC P0500 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-87
.
• If DTC P0500 is displayed with DTC U1010, first pe rform the trouble diagnosis for DTC U1010. Refer
to EC-88
.
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 Diagn osis LogicINFOID:0000000001351655
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:0000000001351656
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 li fted 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-III
1. Start engine (VDC switch OFF).
2. Read “VHCL SPEED SE” in “DATA MONITOR” mode with CONSULT-III. The vehicle speed on CON- SULT-III should exceed 10 km/h (6 MPH) when rotating wheels with suitable gear position.
If NG, go to EC-281, "
Diagnosis Procedure".
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Warm engine up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive seconds.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0500
0500 Vehicle speed sensor The 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 sensor When the fail-safe system for vehicle speed sensor is activated, the cooling fan operates (High) while
engine is running.
ENG SPEED
1,600 - 6,000 rpm
COOLAN TEMP/S More than 70°C (158 °F)
B/FUEL SCHDL 6.9 - 31.8 msec
Selector lever Except P or N position
PW/ST SIGNAL OFF
Revision: March 2010 2008 QX56

EC-296
< COMPONENT DIAGNOSIS >[VK56DE]
P0850 PNP SWITCH
P0850 PNP SWITCH
Component DescriptionINFOID:0000000001351688
When the gear position is P or N, transmission range switch is ON.
TCM detects the position because the conti
nuity of the line (the ON signal) exists.
Then the TCM sends the PNP signal to the ECM via combination meter.
On Board Diagn osis LogicINFOID:0000000001351690
DTC Confirmation ProcedureINFOID:0000000001351691
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.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode with CONSULT-III. Then check the “P/N POSI SW” sig-
nal under the following conditions.
If NG, go to EC-297, "
Diagnosis Procedure".
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-297, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000001351692
Use this procedure to check the overall function of t he park/neutral position (PNP) signal circuit. During this
check, a 1st trip DTC might not be confirmed.
WITH GST
1. Turn ignition switch ON.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0850
0850 Park/neutral position
switch The park/neutral position (PNP) signal is not
changed in the process of engine starting and
driving. • Harness or connectors
[The park/neutral position (PNP) signal
circuit is open or shorted.]
• Combination meter
•TCM
Position (Selector lever) Known-good signal
N or P position ON
Except the above position OFF
ENG SPEED1,000 - 6,375 rpm
COOLAN TEMP/S More than 70°C (158 °F)
B/FUEL SCHDL 2.0 - 31.8 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
Revision: March 2010 2008 QX56

P1572 ICC BRAKE SWITCHEC-341
< COMPONENT DIAGNOSIS > [VK56DE]
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P1572 ICC BRAKE SWITCH
Component DescriptionINFOID:0000000001365766
When the brake pedal is depressed, ICC brake switch is turned OFF
and stop lamp switch is turned ON. ECM detects the state of the
brake pedal by this input of two kinds (ON/OFF signal).
Refer to
CCS-13
for the ICC function.
On Board Diagnosis LogicINFOID:0000000001365768
•This diagnosis has the on e trip detection logic.
• The MIL will not light up for this self-diagnosis.
NOTE:
• If DTC P1572 is displayed with DT C P0605, first perform the trouble diagnosis for DTC P0605. Refer
to EC-291, "
On Board Diagnosis Logic".
• This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when ma lfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
DTC Confirmation ProcedureINFOID:0000000001365769
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
• If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
• Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.
TESTING CONDITION:
Steps 4 and 5 may be conducted with the drive wheels li fted 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-IIl
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-IIl.
3. Press MAIN switch and make sure that CRUISE lamp lights up.
4. Drive the vehicle for at least 5 consecutive seconds under the following conditions.
BBIA0470E
DTC No.Trouble diagnosis
name DTC detecting condition
Possible cause
P1572
1572 ICC brake switch A)
When vehicle speed is above 30 km/h (19
MPH), ON signals from the stop lamp
switch and the ICC brake switch are sent to
ECM at the same time. • Harness or connectors
(The stop lamp switch circuit is shorted.)
• Harness or connectors
(The ICC brake switch circuit is shorted.)
•Stop lamp switch
• ICC brake switch
• ICC brake hold relay
• Incorrect stop lamp switch installation
• Incorrect ICC brake switch installation
•ECM
B)
ICC brake switch signal is not sent to ECM
for extremely long time while the vehicle is
driving
Revision: March 2010
2008 QX56

EC-342
< COMPONENT DIAGNOSIS >[VK56DE]
P1572 ICC BRAKE SWITCH
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to
EC-342, "
Diagnosis Procedure".
If 1st trip DTC is not detec ted, go to the following step.
7. Drive the vehicle for at least 5 consecutive seconds under the following conditions.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-342, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-IIl” above.
Diagnosis ProcedureINFOID:0000000001365771
1.CHECK OVERALL FUNCTION-I
With CONSULT-IIl
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-IIl.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-IIl
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK OVERALL FUNCTION-II
With CONSULT-IIl
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
Driving location Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned vehicle speed.
CONDITION
INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITIONVOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
CONDITIONINDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
Revision: March 2010 2008 QX56

P1572 ASCD BRAKE SWITCHEC-347
< COMPONENT DIAGNOSIS > [VK56DE]
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P1572 ASCD BRAKE SWITCH
Component DescriptionINFOID:0000000001528784
When the brake pedal is depressed,
ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to EC-33, "
System Description" for the ASCD function.
On Board Diagnosis LogicINFOID:0000000001528786
•This self-diagnosis has the one trip detection logic.
• The MIL will not light up for this self-diagnosis.
NOTE:
• If DTC P 1572 is displayed with DTC P0605, first pe rform the trouble diagnosis for DTC P0605. Refer
to EC-291, "
On Board Diagnosis Logic".
• This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when ma lfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
DTC Confirmation ProcedureINFOID:0000000001528787
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
• If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
• Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.
TESTING CONDITION:
Steps 4 and 5 may be conducted with the drive wheels li fted 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-III
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Press MAIN switch and make sure that CRUISE indicator lights up.
4. Drive the vehicle for at least 5 consecutive seconds under the following condition.
BBIA0373E
DTC No.Trouble Diagnosis
Name DTC Detecting Condition
Possible Cause
P1572
1572 ASCD brake switch A)
When the vehicle speed is above 30km/h (19
MPH), ON signals from the stop lamp switch
and the ASCD brake switch are sent to ECM
at the same time. • Harness or connectors
(The stop lamp switch circuit is shorted.)
• Harness or connectors
(The ASCD brake switch circuit is shorted.)
• Stop lamp switch
• ASCD brake switch
• Incorrect stop lamp switch installation
• Incorrect ASCD brake switch installation
•ECM
B)
ASCD brake switch signal is not sent to ECM
for extremely long time while the vehicle is
driving
Revision: March 2010
2008 QX56

EC-348
< COMPONENT DIAGNOSIS >[VK56DE]
P1572 ASCD BRAKE SWITCH
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to
EC-348, "
Diagnosis Procedure".
If 1st trip DTC is not detec ted, go to the following step.
7. Drive the vehicle for at least 5 consecutive seconds under the following condition.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-348, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001528789
1.CHECK OVERALL FUNCTION-I
With CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-III
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK OVERALL FUNCTION-II
With CONSULT-III
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
Driving location Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned condition.
CONDITION
INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITIONVOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
Revision: March 2010 2008 QX56