wiring diagram INFINITI QX56 2010 Factory Service Manual

EC-162
< COMPONENT DIAGNOSIS >[VK56DE]
P0138, P0158 HO2S2
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. Set voltmeter probes between ECM terminal 55 [HO2S2 (B2) signal] or 74\
[HO2S2 (B1) signal] and ground.
6. Check the voltage when revving up to 4,000 rpm under no load at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be below 0. 18 V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0. 18 V at least once during this
procedure.
8. If NG, go to EC-162, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149182
PROCEDURE FOR MALFUNCTION A
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two 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 HO2S2 GROUND CIRCUI T FOR OPEN AND SHORT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4. Refer to Wiring Diagram.
PBIB2054E
BBIA0354E
Continuity should exist.
BBIA0435E
Revision: April 20092010 QX56

P0138, P0158 HO2S2EC-163
< COMPONENT DIAGNOSIS > [VK56DE]
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4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 CONNECTOR FOR WATER
Check connectors for water.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 2
Refer to EC-165, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
PROCEDURE FOR MALFUNCTION B
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
DTC Te r m i n a l s
Bank
ECM Sensor
P0138 5511
P0158 7412
Continuity should exist.
DTC Te r m i n a l s
Bank
ECM Sensor
P0138 5511
P0158 7412
Continuity should not exist.
Water should not exist.
Revision: April 20092010 QX56

EC-164
< COMPONENT DIAGNOSIS >[VK56DE]
P0138, P0158 HO2S2
Refer to EC-85, "Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CLEAR THE SELF-LEARNING DATA
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-III.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con- nector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-55, "
Malfunction Indicator
Lamp (MIL)".
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0172, P0175. Refer to EC-177.
No >> GO TO 3.
3.CHECK HO2S2 GROUND CIRCUI T FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4. Refer to Wiring Diagram.
BBIA0354E
BBIA0368E
BBIA0435E
Revision: April 20092010 QX56

P0138, P0158 HO2S2EC-165
< COMPONENT DIAGNOSIS > [VK56DE]
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5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
3. 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 HEATED OXYGEN SENSOR 2
Refer to EC-165, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000005149183
HEATED OXYGEN SENSOR 2
With CONSULT-III
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. Continuity should exist.
DTC
Te r m i n a l s
Bank
ECM Sensor
P0138 5511
P0158 7412
Continuity should exist.
DTC Te r m i n a l s
Bank
ECM Sensor
P0138 5511
P0158 7412
Continuity should not exist.
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P0139, P0159 HO2S2EC-169
< COMPONENT DIAGNOSIS > [VK56DE]
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NG >> Repair or replace ground connections.
2.CLEAR THE SELF-LEARNING DATA
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “W ORK SUPPORT” mode with CONSULT-III.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con- nector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-55, "
Malfunction Indicator
Lamp (MIL)".
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-172 or EC-177.
No >> GO TO 3.
3.CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4. Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to Wiring Diagram.
BBIA0368E
Continuity should exist.
BBIA0435E
Revision: April 20092010 QX56

EC-170
< COMPONENT DIAGNOSIS >[VK56DE]
P0139, P0159 HO2S2
2. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
3. 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 HEATED OXYGEN SENSOR 2
Refer to EC-170, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000005149189
HEATED OXYGEN SENSOR 2
With CONSULT-III
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. Select “FUEL INJECTION” in “ACT IVE TEST” mode, and select “HO2S2 (B1)/(B2)” as the monitor item
with CONSULT-III.
DTC Te r m i n a l s
Bank
ECM Sensor
P0139 5511
P0159 7412
Continuity should exist.
DTC Te r m i n a l s
Bank
ECM Sensor
P0139 5511
P0159 7412
Continuity should not exist.
Revision: April 20092010 QX56

EC-174
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK FOR INTAKE AIR LEAK
1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding 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.
PBIB1216E
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: April 20092010 QX56

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-179
< COMPONENT DIAGNOSIS > [VK56DE]
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2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK A/F SENSOR 1 IN PUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding 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.
6. Also check harness for short to power.
PBIB1216E
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
Continuity should not exist.
BBIA0376E
Revision: April 20092010 QX56

P0181 FTT SENSOREC-183
< COMPONENT DIAGNOSIS > [VK56DE]
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6. Wait at least 10 seconds.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to
EC-183, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005149199
1.CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
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
BBIA0583E
Voltage: Approximately 5 V
PBIB0932E
Continuity should exist.
Revision: April 20092010 QX56

EC-186
< 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-187, "
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 5 V
PBIB0932E
Continuity should exist.
Revision: April 20092010 QX56