2007 INFINITI QX56 ECU

EC-188
< SERVICE INFORMATION >
DTC P0101 MAF SENSOR
7. Maintain the following conditions for at least 10 consecutive sec-
onds.
8. If 1st trip DTC is detected, go to EC-190, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000003531684
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a 1st trip
DTC might not be confirmed.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in
response to increases to about 4,000 rpm in engine speed.
5. If NG, go to EC-190, "
Diagnosis Procedure".
ENG SPEED More than 2,000 rpm
THRTL SEN 1 More than 3V
THRTL SEN 2 More than 3V
Selector lever Suitable position
Driving locationDriving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
PBIB0199E
SEF534P

DTC P0127 IAT SENSOR
EC-221
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
b. Select “DATA MONITOR” mode with CONSULT-II.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90°C (194°F),
turn ignition switch OFF and cool down engine.
• Perform the following steps before engine coolant temperature
is above 90°C (194°F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 con-
secutive seconds.
6. If 1st trip DTC is detected, go to EC-221, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003531728
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-143, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-221, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
3.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
Refer to EC-202, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionINFOID:0000000003531729
INTAKE AIR TEMPERATURE SENSOR
SEF189Y
BBIA0354E

DTC P0128 THERMOSTAT FUNCTION
EC-223
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
DTC P0128 THERMOSTAT FUNCTION
On Board Diagnosis LogicINFOID:0000000003531731
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leak in the seal or the thermostat stuck open.
DTC Confirmation ProcedureINFOID:0000000003531732
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:
•For best results, perform at ambient temperature of –10°C (14°F) or higher.
•For best results, perform at engine coolant temperature of –10°C (14°F) to 72°C (162°F).
WITH CONSULT-II
1. Replace thermostat with new one. Refer to CO-20 . Use only a genuine NISSAN thermostat as a replace-
ment. If an incorrect thermostat is used, the MIL may come on.
2. Turn ignition switch ON.
3. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-II.
4. Check that the “COOLAN TEMP/S” is above 72°C (162°F).
If it is below 72°C (162°F), go to following step.
If it is above 72°C (162°F), cool down the engine to less than 72°C (162°F), then retry from step 1.
5. Drive vehicle for 10 consecutive minutes under the following conditions.
If 1st trip DTC is detected, go to EC-223, "
Diagnosis Procedure" .
WITH GST
1. Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003531733
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-223, "
Component Inspection" .
OK or NG
OK >>INSPECTION END
NG >> Replace engine coolant temperature sensor.
Component InspectionINFOID:0000000003531734
ENGINE COOLANT TEMPERATURE SENSOR
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128Thermostat functionThe engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough.•Thermostat
• Leakage from sealing portion of thermostat
• Engine coolant temperature sensor
VHCL SPEED SE 80 - 120 km/h (50 - 75 MPH)

DTC P0131, P0151 A/F SENSOR 1
EC-235
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx. 0V, go to EC-239, "
Diagno-
sis Procedure".
If the indication is not constantly approx. 0V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then
restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH)
within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive sec-
onds.
NOTE:
•Keep the accelerator pedal as steady as possible during the cruising.
•If this procedure is not completed within 1 minute after restarting engine at step 4, return to step
4.
7. If 1st trip DTC is displayed, go to EC-239, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
SEF581Z

DTC P0132, P0152 A/F SENSOR 1
EC-243
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx. 5V, go to EC-247, "
Diagno-
sis Procedure".
If the indication is not constantly approx. 5V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then
restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH)
within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive sec-
onds.
NOTE:
•Keep the accelerator pedal as steady as possible during the cruising.
•If this procedure is not completed within 1 minute after restarting engine at step 4, return to step
4.
7. If 1st trip DTC is displayed, go to EC-247, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
SEF581Z

EC-350
< SERVICE INFORMATION >
DTC P0420, P0430 THREE WAY CATALYST FUNCTION
8. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUP-
PORT” mode with CONSULT-II.
9. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecu-
tive 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 until
“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 RESULTS” mode with CONSULT-II.
13. Confirm that the 1st trip DTC is not detected.
If the 1st trip DTC is detected, go to EC-351, "
Diagnosis Proce-
dure".
Overall Function CheckINFOID:0000000003531849
Use this procedure to check the overall function of the three way catalyst (manifold). During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Open engine hood.
6. Set voltmeter probes between ECM terminals ECM terminals 55
[HO2S2 (bank 1) signal], 74 [HO2S2 (bank 2) signal] and
ground.
7. Keep engine speed at 2,500 rpm constant under no load.
8. Make sure that the voltage does not vary for more than 5 sec-
onds.
If the voltage fluctuation cycle takes less than 5 seconds, go to
EC-351, "
Diagnosis Procedure".
• 1 cycle: 0.6 - 1.0 → 0 - 0.3 → 0.6 - 1.0
PBIB1784E
PBIB1785E
SEF535Z
PBIB2056E

DTC P0442 EVAP CONTROL SYSTEM
EC-361
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
2. Check for genuine NISSAN fuel filler cap design.
OK or NG
OK >> GO TO 2.
NG >> Replace with genuine NISSAN fuel filler cap.
2.CHECK FUEL FILLER CAP INSTALLATION
Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3.CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-35, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
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 EVAP service port adapter to the
EVAP service port may cause leaking.
With CONSULT-II>>GO TO 6.
Without CONSULT-II>>GO TO 7.
SEF915U
BBIA0366E
SEF916U

DTC P0455 EVAP CONTROL SYSTEM
EC-409
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
•Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid valve
properly.
• 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:
•Perform “DTC WORK SUPPORT” when the fuel level is between 1/4 and 3/4 full, and vehicle is placed
on flat level surface.
•Open engine hood before conducting the following procedures.
WITH CONSULT-II
1. Tighten fuel filler cap securely until ratcheting sound is heard.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
5. Make sure that the following conditions are met.
COOLAN TEMP/S: 0 - 70°C (32 - 158°F)
INT/A TEMP SE: 0 - 60°C (32 - 140°F)
6. Select “EVP SML LEAK P0442/P1442” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-II.
Follow the instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on the CONSULT-II screen, go to
EC-71, "
Basic Inspection".
7. Make sure that “OK” is displayed.
If “NG” is displayed, select “SELF-DIAG RESULTS” mode and
make sure that “EVAP GROSS LEAK [P0455]” is displayed. If it
is displayed, refer to EC-410, "
Diagnosis Procedure".
If P0442 is displayed, perform Diagnostic Procedure for DTC
P0442, EC-360, "
Diagnosis Procedure".
WITH GST
NOTE:
Be sure to read the explanation of EC-49, "
Emission-related Diagnostic Information" before driving vehicle.
1. Start engine.
2. Drive vehicle according to EC-49, "
Emission-related Diagnostic Information".
3. Stop vehicle.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Select Service $07 with GST.
• If P0441 is displayed on the screen, go to EC-356, "
Diagnosis Procedure".
• If P0442 is displayed on the screen, go to EC-360, "
Diagnosis Procedure".
• If P0455 is displayed on the screen, go to EC-410, "
Diagnosis Procedure".
PBIB0829E
SEC763C