2009 INFINITI QX56 display

P0116 ECT SENSOREC-117
< COMPONENT DIAGNOSIS > [VK56DE]
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P0116 ECT SENSOR
Component DescriptionINFOID:0000000003771369
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor
modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals wh en measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000003771370
DTC Confirmation ProcedureINFOID:0000000003771371
NOTE:
If DTC P0116 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-121, "DTC Confirmation Procedure"
.
 If DTC confirmation procedure has been previously c onducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, do not fill with the fuel.
1. Start engine and warm it up to normal operating temperature.
2. Rev engine up to 2,000 rpm for more than10 minutes.
3. Move the vehicle to a cool place, then stop engine and turn ignition switch OFF.
4. Check resistance between “fuel level sensor and fuel pump” terminals 3 and 4.
5. Soak the vehicle until the resistance between “fuel level sensor and fuel pump” terminals 3 and 4
becomes 0.5 k Ω higher than the value measured before soaking.
SEF594K
Engine coolant
temperature °C ( °F)] Voltage* (V) Resistance (k
Ω)
− 10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0116
0116 Engine coolant tempera-
ture sensor circuit range/
performance Engine coolant temperature signal from engine
coolant temperature sensor does not fluctuate,
even when some time has passed after starting
the engine with pre-warming up condition.  Harness or connectors
(High or low resistance in the circuit)
 Engine coolant temperature sensor
Revision: December 20092009 QX56

EC-120
< COMPONENT DIAGNOSIS >[VK56DE]
P0117, P0118 ECT SENSOR
P0117, P0118 ECT SENSOR
Component DescriptionINFOID:0000000003771374
The engine coolant temperature sens
or is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The elec trical resistance of the ther-
mistor decreases as temperature increases.

*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring in put/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000003771375
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
SEF594K
Engine coolant temperature
°C ( °F)] Voltage* (V) Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No. Trouble Diagnosis Na
me DTC Detecting Cond ition Possible Cause
P0117
0117 Engine coolant temperature
sensor circuit low input An excessively low voltage from the sensor is
sent to ECM.
 Harness or connectors
(The sensor circuit is open or shorted.)
 Engine coolant temperature sensor
P0118
0118 Engine coolant temperature
sensor circuit high input An excessively high voltage from the sensor is
sent to ECM.
Detected items Engine operating condition in fail-safe mode
Engine coolant temper- ature sensor circuit Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT-III displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-III display)
Just as ignition switch is turned ON or START 40 °C (104 °F)
Approx 4 minutes or more after engine 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.
Revision: December 20092009 QX56

EC-128
< COMPONENT DIAGNOSIS >[VK56DE]
P0125 ECT SENSOR
P0125 ECT SENSOR
Component DescriptionINFOID:0000000003771384
The engine coolant temperature sens
or is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The elec trical resistance of the ther-
mistor decreases as temperature increases.

*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring in put/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000003771385
DTC Confirmation ProcedureINFOID:0000000003771386
CAUTION:
Be careful not to overheat engine.
NOTE:
If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-121, "DTC Confirmation Procedure"
.
 If DTC P0125 is displayed with P0116, first perf orm the trouble diagnosis for DTC P011. Refer to EC-
117, "DTC Confirmation Procedure".
1. If DTC Confirmation Procedure has been previously conducted, always perform the following before con-
ducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
SEF594K
Engine coolant temperature °C ( °F)] Voltage* (V) Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0125
0125 Insufficient engine coolant
temperature for closed loop
fuel control  Voltage sent to ECM from the sensor is not
practical, even when some time has passed
after starting the engine.
 Engine coolant temperature is insufficient for closed loop fuel control.  Harness or connectors
(High resistance in the circuit)
 Engine coolant temperature sensor
Thermostat
Revision: December 20092009 QX56

EC-134
< COMPONENT DIAGNOSIS >[VK56DE]
P0128 THERMOSTAT FUNCTION
P0128 THERMOSTAT FUNCTION
On Board Diagn
osis LogicINFOID:0000000003771394
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 or P0308,
first perform the trouble diagnosis for DTC P 0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307,
P0308. Refer to EC-189, "DTC Confi rmation Procedure"
.
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:0000000003771395
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.
TESTING CONDITION:
 For best results, perform at ambient temperature of –10 °C (14 °F) or higher.
 For best results, perform at en gine coolant temperature of –10 °C (14 °F) to 52 °C (126 °F).
 Before performing the following procedure, do not fill with the fuel.
1. Turn A/C switch OFF.
2. Turn blower fan switch OFF.
3. Turn ignition switch ON.
4. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-III.
5. Check the indication of “COOLAN TEMP/S”. If it is below 52 °C (126 °F), go to following step.
If it is above 52 °C (126 °F), cool down the engine to less than 52 °C (126 °F). Then go to next steps.
6. Start engine and wait at idle for at least 30 minutes. If “COOLAN TEMP/S” increases to more than 71 °C (160 °F) within 30 minutes, turn ignition switch
OFF because the test result will be OK.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-134, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771396
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-134, "Component Inspection"
.
OK or NG
OK >> GO TO 2.
NG >> Replace engine coolant temperature sensor.
2.CHECK THERMOSTAT
Refer to CO-22, "Removal and Installation"
.
OK or NG
OK >> INSPECTION END
NG >> Replace thermostat.
Component InspectionINFOID:0000000003771397
ENGINE COOLANT TEMPERATURE SENSOR
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128 Thermostat function The 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
Revision: December 20092009 QX56

P0130, P0150 A/F SENSOR 1EC-137
< COMPONENT DIAGNOSIS > [VK56DE]
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PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)
” in “DATA MONITOR” mode with CONSULT-III.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx . 2.2V and does not fluctuates, go to EC-137, "Diagnosis Procedure"
.
If the indication fluctuates around 2.2V, go to next step.
4. Select “A/F SEN1 (B1) P1276” (for DTC P0130) or “A/F SEN1 (B2) P1286” (for DTC P0150) of “A/F
SEN1” in “DTC WORK SUPPORT” mode with CONSULT-III.
5. Touch “START”.
6. When the following conditions are met, “TESTIN G” will be displayed on the CONSULT-III screen.
If “TESTING” is not displayed after 20 seconds, retry from step 2.
7. Release accelerator pedal fully. NOTE:
Never apply brake during releasing the accelerator pedal.
8. Make sure that “TESTING” changes to “COMPLETED”. If “TESTING” changed to “OUT OF CONDITION”, retry from step 6.
9. Make sure that “OK” is display ed after touching “SELF-DIAG RESULT”.
If “NG” is displayed, go to EC-137, "Diagnosis Procedure"
.
Overall Function CheckINFOID:0000000003771401
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the A/F sensor 1 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. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in the suitable gear position.
3. Set shift lever to D position, then release the a ccelerator pedal fully until the vehicle speed decreases to
50 km/h (30 MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
4. Repeat steps 2 and 3 for five times.
5. Stop the vehicle and turn ignition switch OFF.
6. Wait at least 10 seconds and restart engine.
7. Repeat steps 2 and 3 for five times.
8. Stop the vehicle and connect GST to the vehicle.
9. Make sure that no 1st trip DTC is displayed.
If the 1st trip DTC is displayed, go to EC-137, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771402
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
ENG SPEED 850 - 3,200 rpm
VHCL SPEED SE More than 64 km/h (40 MPH)
B/FUEL SCHDL 1.0 - 8.0 msec
Shift lever D position
Revision: December 20092009 QX56

P0131, P0151 A/F SENSOR 1EC-141
< COMPONENT DIAGNOSIS > [VK56DE]
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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. Check 1st trip DTC.
8. If 1st trip DTC is displayed, go to EC-141, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771406
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 4 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
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
BBIA0354E
Voltage: Battery voltage
BBIA0376E
PBIB3308E
Revision: December 20092009 QX56

EC-144
< COMPONENT DIAGNOSIS >[VK56DE]
P0132, P0152 A/F SENSOR 1
NOTE:

Keep the accelerator pedal as steady as possible during the cruising.
 If this procedure is not completed within 1 minute af ter restarting engine at step 4, return to step
4.
7. Check 1st trip DTC.
8. If 1st trip DTC is displayed, go to EC-144, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771410
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 4 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More th an 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
BBIA0354E
Voltage: Battery voltage
BBIA0376E
PBIB3308E
Revision: December 20092009 QX56

P0133, P0153 A/F SENSOR 1EC-147
< COMPONENT DIAGNOSIS > [VK56DE]
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1. Start engine and warm it up to 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 1minute under no load.
4. Let engine idle for 1 minute.
5. Select “A/F SEN1(B1) P1278/P1279”
(for DTC P0133) or “A/F SEN1(B2) P1288/P1289” (for DTC P0153)
of “A/F SEN1” in “DTC WORK SUPPORT” mode with CONSULT-III.
6. Touch “START”. If “COMPLETED” appears on CONSULT-III screen, go to step 10.
If “COMPLETED” does not appear on CONSULT- III screen, go to the following step.
7. After perform the following procedure, “TESTIN G” will be displayed on the CONSULT-III screen.
a. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
b. Fully release accelerator pedal and then let engine idle for about 10 seconds. If “TESTING” is not displayed after 10 seconds, refer to EC-74
.
8. Wait for about 20 seconds at idle under the conditi on that “TESTING” is displayed on the CONSULT-III
screen.
9. Make sure that “TESTING” changes to “COMPLETED”. If “TESTING” changed to “OUT OF CONDITION”, refer to EC-74
.
10. Make sure that “OK” is display ed after touching “SELF-DIAG RESULT”.
If “NG” is displayed, go to EC-147, "Diagnosis Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Calculate the total value of “Short term f uel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within ±15%.
If OK, go to the following step.
If NG, check the following.
 Intake air leaks
 Exhaust gas leaks
 Incorrect fuel pressure
 Lack of fuel
 Fuel injector
 Incorrect PCV hose connection
 PCV valve
 Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select Service $07 with GST. If the 1st trip DTC is displayed, go to EC-147, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771414
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Revision: December 20092009 QX56