2008 INFINITI QX56 diagram

EC-122
< COMPONENT DIAGNOSIS >[VK56DE]
P0116 ECT SENSOR
Soak time changes depending on ambient ai
r temperature. It may take several hours.
6. Start engine and let it idle for 5 minutes.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-122, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000003760277
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-122, "
Component Inspection".
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
3.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
For Wiring Diagram, refer to EC-439, "
Wiring Diagram - ENGINE CONTROL SYSTEM -".
>> INSPECTION END
Component InspectionINFOID:0000000003760278
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.
BBIA0354E
PBIB2005E
Revision: March 2010 2008 QX56

EC-126
< COMPONENT DIAGNOSIS >[VK56DE]
P0117, P0118 ECT SENSOR
3. Check voltage between ECT sensor (1) terminal 1 and ground
with CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING RART
Check the following.
• Harness connector F26, F101
• Harness for open or short between ECM and engine coolant temperature sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECT sensor terminal 2 and ECM terminal 67. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
• Harness connector F26, F101
• Harness for open and short between ECT sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-126, "
Component Inspection".
OK or NG
OK >> GO TO 7.
NG >> Replace engine coolant temperature sensor.
7.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351430
ENGINE COOLANT TEMPERATURE SENSOR
Voltage: Approximately 5V
PBIB0080E
Continuity should exist.
Revision: March 2010 2008 QX56

P0122, P0123 TP SENSOREC-129
< COMPONENT DIAGNOSIS > [VK56DE]
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Refer to
EC-86, "Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle c ontrol actuator harness connector.
2. Turn ignition switch ON.
3. Check voltage between electric throttle control actuator terminal 2 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3.CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric thrott le control actuator terminal 2 and ECM terminal 47.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace open circuit.
4.CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
BBIA0354E
PBIB1480E
Voltage: Approximately 5V
PBIB2065E
Continuity should exist.
ECM terminalSensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-439, "
Wiring Diagram - ENGINE
CONTROL SYSTEM -"91APP sensor terminal 6
Revision: March 2010 2008 QX56

EC-130
< COMPONENT DIAGNOSIS >[VK56DE]
P0122, P0123 TP SENSOR
OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-384, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 6.
6.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-18, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-18, "
Throttle Valve Closed Position Learning" .
4. Perform EC-18, "
Idle Air Volume Learning" .
>> INSPECTION END
7.CHECK THROTTLE POSITION SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric thrott le control actuator terminal 4 and ECM terminal 66.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK THROTTLE POSITION SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 69 and electric throttle control actuator terminal 3. Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK THROTTLE POSITION SENSOR
Refer to EC-131, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-18, "
Throttle Valve Closed Position Learning" .
3. Perform EC-18, "
Idle Air Volume Learning" .
>> INSPECTION END
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
Continuity should exist.
Continuity should exist.
Revision: March 2010
2008 QX56

P0125 ECT SENSOREC-133
< COMPONENT DIAGNOSIS > [VK56DE]
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4. Start engine and run it for 65 minutes at idle speed.
If “COOLAN TEMP/S” increases to more than 31° C (88°F) within 65 minutes, stop engine because
the test result will be OK.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-133, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351443
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-133, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
3.CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70 °C (158° F)] condition, grasp lower radiator hose and confirm the engine
coolant does not flow.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace thermostat. Refer to CO-22, "
Removal and Installation" .
4.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
Refer to EC-439, "
Wiring Diagram - ENGINE CONTROL SYSTEM -" .
>> INSPECTION END
Component InspectionINFOID:0000000001351444
ENGINE COOLANT TEMPERATURE SENSOR
BBIA0354E
Revision: March 2010 2008 QX56

EC-136
< COMPONENT DIAGNOSIS >[VK56DE]
P0127 IAT SENSOR
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to
EC-136, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351449
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-136, "
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 GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
Refer to EC-439, "
Wiring Diagram - ENGINE CONTROL SYSTEM -" .
>> INSPECTION END
Component InspectionINFOID:0000000001351450
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between intake air temperature sensor termi-
nals 5 and 6 under the following conditions.
2. If NG, replace mass air flow sens or (with intake air temperature
sensor).
BBIA0354E
Intake air temperature °C ( °F) Resistance k Ω
25 (77) 1.800 - 2.200
BBIA0355E
Revision: March 2010 2008 QX56

P0130, P0150 A/F SENSOR 1EC-143
< COMPONENT DIAGNOSIS > [VK56DE]
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Refer to
EC-86, "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
Check the following.
• Harness connectors E5, F14
• IPDM E/R harness connector E119
• 15A fuse
• Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
4.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals. Refer to Wiring Diagram.
BBIA0354E
Voltage: Battery voltage
BBIA0376E
PBIB3308E
A/F sensor 1 terminal ECM terminal
Bank1 13
5
25 6
Revision: March 2010 2008 QX56

EC-144
< COMPONENT DIAGNOSIS >[VK56DE]
P0130, P0150 A/F SENSOR 1
4. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
OK or NG
OK >> GO TO 6.
NG >> Repair or replace.
6.REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air fuel ratio (A/F) sensor 1.
CAUTION:
• Discard any 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 A/F sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
>>INSPECTION END
Bank 2 116
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
Continuity should not exist.
Revision: March 2010 2008 QX56