2008 INFINITI QX56 Fuel sensor

EC-192
< COMPONENT DIAGNOSIS >[VK56DE]
P0182, P0183
FTT SENSOR
2. Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.
3. Turn ignition switch ON.
4. Check voltage between “fuel level sensor unit and fuel pump”
terminal 4 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors C1, E41
• Harness for open or short between ECM and “fuel level sensor unit and fuel pump”
>> Repair harness or connector.
3.CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between “fuel level sensor unit and fuel pump” terminal 3 and ground. Refer to
Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors C1, E41
• Harness for open or short between “fuel level sensor unit and fuel pump” and ground
>> Repair open circuit or short to power in harness or connector.
5.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-193, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace “fuel level sensor unit and fuel pump”.
6.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
BBIA0583E
Voltage: Approximately 5V
PBIB0932E
Continuity should exist.
Revision: March 2010 2008 QX56

P0182, P0183 FTT SENSOREC-193
< COMPONENT DIAGNOSIS > [VK56DE]
C
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F
G H
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K L
M A
EC
NP
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>>
INSPECTION END
Component InspectionINFOID:0000000001351533
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between “fuel level sensor unit and fuel pump”
terminals 3 and 4 by heating with hot water as shown in the fig-
ure.
If NG, replace fuel level sensor unit.
Temperature °C ( °F) Resistance kΩ
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
SEF476YA
Revision: March 2010 2008 QX56

EC-198
< COMPONENT DIAGNOSIS >[VK56DE]
P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MIS-
FIRE
On Board Diagn osis LogicINFOID:0000000001351543
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary , ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage) On the 1st trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to over-
heating, the MIL will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can dam age the TWC on a second trip, the MIL will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC, the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration) For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MIL will only
light when the misfire is detected on a second trip. Du ring this condition, the ECM monitors the CKP sen-
sor signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC Confirmation ProcedureINFOID:0000000001351544
CAUTION:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws when driv-
ing.
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
Sensor Input signal to ECM ECM function
Crankshaft position sensor (POS) Engine speedOn board diagnosis of misfire
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300
0300 Multiple cylinder misfire
detected
Multiple cylinder misfire.
• Improper spark plug
• Insufficient compression
• Incorrect fuel pressure
• The injector circuit is open or shorted
• Fuel injector
• Intake air leak
• The ignition signal circuit is open or short-ed
• Lack of fuel
• Signal plate
• Air fuel ratio (A/F) sensor 1
• Incorrect PCV hose connection
P0301
0301
No.1 cylinder misfire de-
tected
No. 1 cylinder misfires.
P0302
0302 No. 2 cylinder misfire
detected
No. 2 cylinder misfires.
P0303
0303 No. 3 cylinder misfire
detected
No. 3 cylinder misfires.
P0304
0304 No. 4 cylinder misfire
detected
No. 4 cylinder misfires.
P0305
0305 No. 5 cylinder misfire
detected
No. 5 cylinder misfires.
P0306
0306 No. 6 cylinder misfire
detected
No. 6 cylinder misfires.
P0307
0307 No. 7 cylinder misfire
detected
No. 7 cylinder misfires.
P0308
0308 No. 8 cylinder misfire
detected
No. 8 cylinder misfires.
Revision: March 2010
2008 QX56

EC-202
< COMPONENT DIAGNOSIS >[VK56DE]
P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check the following.
• Fuel pump and circuit (Refer to EC-402, "
Diagnosis Procedure".)
• Fuel pressure regulator (Refer to EC-494, "
Fuel Pressure Check".)
• Fuel lines
• Fuel filter for clogging
>> Repair or replace.
12.CHECK IGNITION TIMING
Check the following items. Refer to EC-13, "
Basic Inspection".
OK or NG
OK >> GO TO 13.
NG >> Follow the EC-13, "
Basic Inspection".
13.CHECK A/F SENSOR 1 INPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals. Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
Items Specifications
Target idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5 ° BTDC (in P or N position)
A/F sensor 1 terminal ECM terminal
Bank 1 13
5
25 6
Bank 2 11
6
27 5
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 13 511 6
25 627 5
BBIA0376E
Revision: March 2010 2008 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-203
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
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F
G H
I
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K L
M A
EC
NP
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6. Also check harness for short to power.
OK or NG
OK >> GO TO 14.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
14.CHECK A/F SENSOR 1 HEATER
Refer to EC-99, "
Component Inspection".
OK or NG
OK >> GO TO 16.
NG >> GO TO 15.
15.REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air f uel ratio (A/F) sensor 1.
CAUTION:
• Discard any air fuel ratio (A/F) sensor which has b een dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
• Before installing new air fuel ra tio (A/F) sensor, clean exhaust syst em threads (using Oxygen Sensor
Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
16.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
Check mass air flow sensor signal in “DATA MONITOR” mode with CONSULT-III.
With GST
Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 17.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or ground. Refer to EC-106
.
17.CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in EC-481, "
Symptom Matrix Chart".
OK or NG
OK >> GO TO 18.
NG >> Repair or replace.
18.ERASE THE 1ST TRIP DTC
Some tests may cause a 1st trip DTC to be set.
Erase the 1st trip DTC from the ECM memory after performing the tests. Refer to EC-462, "
DTC Index".
>> GO TO 19.
19.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Continuity should not exist.
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
Revision: March 2010
2008 QX56

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-215
< COMPONENT DIAGNOSIS > [VK56DE]
C
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G H
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EC
NP
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P0420, P0430 THREE WAY CATALYST FUNCTION
On Board Diagnosis LogicINFOID:0000000001351568
The ECM monitors the switching
frequency ratio of air fuel sensor
(A/F) sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decreases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated
oxygen sensor 2 approaches a specified limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation ProcedureINFOID:0000000001351569
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
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C (158° F).
If not, warm up engine and go to next step when “COOLAN TEMP/S” indication reaches to 70°C (158° F).
7. Open engine hood.
8. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUPPORT” mode with CONSULT-III.
9. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecutive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “CMPLT”, go to step 12.
10. Wait 5 seconds at idle.
11. Rev engine up to 2,000 to 3,000 rpm and maintain it unt il “INCMP” of “CATALYST” changes to “CMPLT” (It
will take approximately 5 minutes).
If not “CMPLT”, stop engine and cool it down to less than 70 °C (158° F) and then retest from step 1.
12. Select “SELF-DIAG RESU LTS” mode with CONSULT-III.
13. Confirm that the 1st trip DTC is not detected. If the 1st trip DTC is detected, go to EC-216, "
Diagnosis Procedure".
PBIB2055E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420
(Bank 1) Catalyst system efficien-
cy below threshold • Three way catalyst (manifold) does not oper-
ate properly.
• Three way catalyst (manifold) does not have enough oxygen storage capacity. • Three way catalyst (manifold)
• Exhaust tube
• Intake air leaks
• Fuel injector
• Fuel injector leaks
• Spark plug
• Improper ignition timing
P0430
0430
(Bank 2)
Revision: March 2010
2008 QX56

EC-220
< COMPONENT DIAGNOSIS >[VK56DE]
P0441 EVAP CONTROL SYSTEM
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and let it idle for at least 70 seconds.
4. Select “PURG FLOW P0441” of “EVAPORATIVE
SYSTEM” in “DTC WORK SUPPORT” mode with CON-
SULT-III.
5. Touch “START”. If “COMPLETED” is displayed, go to step 7.
6. When the following conditions are met, “TESTING” will be displayed on the CONSULT-III screen. Maintain
the conditions continuously until “TESTING” changes to “COMPLETED”. (It will take at least 35 seconds.)
If “TESTING” is not changed for a long time, retry from step 2.
7. Make sure that “OK” is displayed after touching “ SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
220, "Diagnosis Procedure".
Overall Function CheckINFOID:0000000001351575
Use this procedure to check the overall monitoring func tion of the EVAP control system purge flow monitoring.
During this check, a 1st trip DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
2. Start engine (VDC switch OFF) and warm it up to normal operating temperature.
3. Turn ignition switch OFF, wait at least 10 seconds.
4. Start engine and wait at least 70 seconds.
5. Set voltmeter probes to ECM terminals 32 (EVAP control system pressure sensor signal) and ground.
6. Check EVAP control system pre ssure sensor value at idle speed
and note it.
7. Establish and maintain the following conditions for at least 1 minute.
8. Verify that EVAP control system pressure sensor va lue stays 0.1V less than the value at idle speed (mea-
sured at step 6) for at least 1 second.
9. If NG, go to EC-220, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001351576
1.CHECK EVAP CANISTER
1. Turn ignition switch OFF.
2. Check EVAP canister for cracks.
OK or NG
OK (With CONSULT-III)>>GO TO 2.
OK (Without CONSULT-III)>>GO TO 3.
NG >> Replace EVAP canister.
2.CHECK PURGE FLOW
Selector lever Suitable position
VHCL SPEED SE 32 - 120 km/h (20 - 75 MPH)
ENG SPEED 500 - 3,000 rpm
B/FUEL SCHDL 1.0 - 12.0 msec
COOLAN TEMP/S 0 - 119°C (32 - 246 °F)
Air conditioner switch ON
Headlamp switch ON
Rear window defogger switch ON
Engine speed Approx. 3,000 rpm
Gear position Any position other than P, N or R
PBIB1109E
Revision: March 2010 2008 QX56

EC-224
< COMPONENT DIAGNOSIS >[VK56DE]
P0442 EVAP CONTROL SYSTEM
P0442 EVAP CONTROL SYSTEM
On Board Diagn
osis LogicINFOID:0000000001351577
This diagnosis detects leaks in the EVAP purge line using engine intake manifold vacuum.
If pressure does not increase, the ECM will check for leaks in the line between the fuel tank and EVAP canister
purge volume control solenoid valve, under the following “Vacuum test” conditions.
The EVAP canister vent control valve is closed to shut the EVAP purge line off. The EVAP canister purge vol-
ume control solenoid valve will then be opened to depressurize the EVAP purge line using intake manifold
vacuum. After this occurs, the EVAP canister purge volume control solenoid valve will be closed.
CAUTION:
• Use only a genuine NISSAN fuel filler cap as a replacemen t. If an incorrect fuel filler cap is used, the
MIL may come on.
• If the fuel filler cap is not tigh tened properly, the MIL may come on.
• Use only a genuine NISSAN rubber tube as a replacement.
DTC Confirmation ProcedureINFOID:0000000001351578
NOTE:
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0442
0442 EVAP control system
small leak detected
(negative pressure) EVAP control system has a leak, EVAP
control system does not operate prop-
erly. • Incorrect fuel tank vacuum relief valve
• Incorrect fuel filler cap used
• Fuel filler cap remains open or fails to close.
• Foreign matter caught in fuel filler cap.
• Leak is in line between intake manifold and EVAP
canister purge volume control solenoid valve.
• Foreign matter caught in EVAP canister vent con- trol valve.
• EVAP canister or fuel tank leaks
• EVAP purge line (pipe and rubber tube) leaks
• EVAP purge line rubber tube bent
• Loose or disconnected rubber tube
• EVAP canister vent control valve and the circuit
• EVAP canister purge volume control solenoid valve and the circuit
• Fuel tank temperature sensor
• O-ring of EVAP canister vent control valve is missing or damaged
• EVAP canister is saturated with water
• EVAP control system pressure sensor
• Fuel level sensor and the circuit
• Refueling EVAP vapor cut valve
• ORVR system leaks
PBIB1026E
Revision: March 2010 2008 QX56