ground INFINITI QX56 2011 Factory Service Manual

EC-382
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0643 SENSOR POWER SUPPLY
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair short to ground or short to power in harness or connectors.
3.CHECK COMPONENTS
Check the following.
 Camshaft position sensor (bank 2) (Refer to EC-306, "
Component Inspection (Camshaft Position Sensor)".)
 Manifold absolute pressure (MAP) sensor (Refer to EC-208, "
Component Inspection (MAP Sensor)".)
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace malfunctioning component.
4.CHECK THROTTLE POSITION SENSOR
Refer to EC-220, "
Component Inspection (Throttle Position Sensor)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 5.
5.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
Replace electric throttle control actuator. Refer to EM-30, "
Removal and Installation".
>> INSPECTION END
6.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-470, "
Component Inspection (Accelerator Pedal Position Sensor)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 7.
7.REPLACE ACCELERATOR PEDAL ASSEMBLY
Replace accelerator pedal assembly. Refer to ACC-3, "
MODELS WITHOUT DISTANCE CONTROL ASSIST
SYSTEM : Removal and Installation" (Without distance control assist system) or ACC-4, "MODELS WITH
DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation" (With distance control assist system).
>> INSPECTION END
8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 81 Electric throttle control actuator F66 2
83 Camshaft position sensor (bank 2) F83 1
85 Manifold absolute pressure (MAP) sensor F65 1
E80 137 APP sensor 1 (Without ICC) E110 2
137 APP sensor 1 (With ICC) E67 12
Revision: 2010 May2011 QX56

P0850 PNP SWITCHEC-385
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between A/T assembly and ECM
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
A/T assembly ECM Continuity
Connector Terminal Connector Terminal
F 3 0 1 9 F 111 11 E x i s t e d
Revision: 2010 May2011 QX56

P1089, P1092 VVEL CONTROL SHAFT POSITION SENSOR
EC-387
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P1089, P1092 VVEL CONTROL
SHAFT POSITION SENSOR
DTC LogicINFOID:0000000006217894
DTC DETECTION LOGIC
NOTE:
If DTC P1089 or P1092 is displayed with DTC P1608, first perform the trouble diagnosis for DTC P1608.
Refer to EC-453, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is 10 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for 1 second.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-387, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217895
1.VVEL CONTROL SHAFT POSITION SENSOR POWER SUPPLY CIRCUIT
1. Disconnect VVEL control shaft pos ition sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between VVEL control shaf t position sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1089 VVEL POS SEN/CIRC-B1
[VVEL control shaf
t position sen-
sor (bank 1) circuit]  An excessively low voltage from the sensor
is sent to VVEL control module.
 An excessively high voltage from the sensor is sent to VVEL control module.
 Rationally incorrect voltage is sent to VVEL control module compared with the signals
from VVEL control shaft position sensor 1
and VVEL control shaft position sensor 2.  Harness or connectors
(VVEL control shaft position sen-
sor circuit is open or shorted.)
 VVEL control shaft position sen- sor
 VVEL control module
P1092 VVEL POS SEN/CIRC-B2
[VVEL control shaf
t position sen-
sor (bank 2) circuit]
DTC No. VVEL control shaft position sensor
Ground Voltage (V)
Bank Connector Terminal
P1089 1 F72 3
Ground Approx. 5
6
P1092 2 F70 3
6
Revision: 2010 May2011 QX56

EC-388
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1089, P1092 VVEL CONTRO
L SHAFT POSITION SENSOR
 Harness for open or short between VVEL control shaft position sensor and VVEL control module
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK VVEL CONTROL SHAFT POSITION SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect VVEL control module harness connector.
3. Check the continuity between VVEL control shaf t position sensor harness connector and VVEL control
module harness connector.
4. Also check harness for short to ground and power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between VVEL control shaft position sensor and VVEL control module
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
5.VVEL CONTROL SHAFT POSITI ON SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between VVEL control shaf t position sensor harness connector and VVEL control
module harness connector.
2. Also check harness for short to ground and power.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between VVEL control shaft position sensor and VVEL control module
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
DTC No. VVEL control shaft position
sensor VVEL control module
Continuity
Bank Connector Terminal Connector Terminal
P1089 1 F72 2
F56 6
Existed
519
P1092 2 F70 24
517
DTC No.VVEL control shaft position
sensor VVEL control module
Continuity
Bank Connector Terminal Connector Terminal
P1089 1 F72 1
F56 3
Existed
416
P1092 2 F70 15
418
Revision: 2010 May2011 QX56

P1090, P1093 VVEL ACTUATOR MOTOREC-391
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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4. Also check harness for short to ground and power.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between VVEL actuat or motor assembly and VVEL control module
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK VVEL ACTUATOR MOTOR ASSEMBLY
Refer to EC-392, "
Component Inspection (VVEL ACTUATOR MOTOR ASSEMBLY)".
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.REPLACE VVEL ACTUATOR MOTOR ASSEMBLY
Replace VVEL actuator motor assembly. Refer to EM-75, "
Removal and Installation".
>> INSPECTION END
5.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace.
6.REPLACE VVEL CONTROL MODULE
1. Replace VVEL control module.
2. Perform additional service when replacing VVEL control module. Refer to EC-144, "
Work Procedure".
>> GO TO 7.
7.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Erase DTC.
3. Perform DTC Confirmation Procedure. See EC-390, "
DTC Logic".
Is the DTC P1090 or P1093 displayed again?
YES >> GO TO 8.
NO >> INSPECTION END
8.CHECK VVEL ACTUATOR HOUSING ASSEMBLY
Refer to EC-392, "
Component Inspection (VVEL ACTUATOR MOTOR ASSEMBLY)".
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 9.
9.REPLACE VVEL ACTUATOR HOUSING ASSEMBLY
Replace VVEL actuator housing assembly. Refer to EM-75, "
Removal and Installation".
>> INSPECTION END
10.CHECK VVEL LADDER ASSEMBLY
Refer to EM-77, "
Inspection".
Revision: 2010 May2011 QX56

P1091 VVEL ACTUATOR MOTOR RELAYEC-393
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P1091 VVEL ACTUATOR MOTOR RELAY
DTC LogicINFOID:0000000006217900
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is 10 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 1 seconds.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and wait at least 1 seconds.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-393, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217901
1.VVEL ACTUATOR MOTOR RELAY POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect VVEL actuator motor relay.
3. Check the voltage between VVEL actuator motor relay harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 50A fusible link (letter O)
 Harness for open or short between VVEL actuator motor relay and battery
>> Repair open circuit, short to ground or short to power in harness or connectors.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1091 VVEL ACTR MOT PWR
[VVEL actuator motor relay
circuit]  VVEL control module detects the VVEL
actuator motor relay is stuck OFF.
 VVEL control module detects the VVEL actuator motor relay is stuck ON.  Harness or connectors
(VVEL actuator motor rela y circuit is open or
shorted.)
(Abort circuit is open or shorted.)
 VVEL actuator motor relay
 VVEL control module
ECM
VVEL actuator motor relay Ground Voltage
Connector Terminal
E62 1
Ground Battery voltage
3
Revision: 2010 May2011 QX56

EC-394
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1091 VVEL ACTUATOR MOTOR RELAY
3.VVEL ACTUATOR MOTOR RELAY POWER SUPPLY CIRCUIT-II
1. Disconnect VVEL control module harness connector.
2. Check the continuity between VVEL actuator mo tor relay harness connector and VVEL control module
harness connector.
3. Also check harness for short to ground and power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.VVEL ACTUATOR MOTOR RELAY INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between VVEL actuator motor relay harness connector and VVEL control module
harness connector.
2. Also check harness for short to ground and power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK VVEL ACTUATOR MOTOR RELAY
Refer to EC-395, "
Component Inspection (VVEL Actuator Motor Relay)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace VVEL actuator motor relay.
6.CHECK ABORT CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check the continuity between VVEL contro l module harness connector and ECM harness connector.
3. Also check harness for short to ground and power.
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open and short between ECM and VVEL control module
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
VVEL control module VVEL actuator motor relay
Continuity
Connector Terminal Connector Terminal
F56 23 E62 2 Existed
VVEL control module VVEL actuator motor relay
Continuity
Bank Connector Terminal Connector Terminal
1 F56 13
E62 5 Existed
21
VVEL control module ECM Continuity
Connector Terminal Connector Terminal
F56 21 E80 122 Existed
Revision: 2010 May2011 QX56

P1220 FUEL PUMP CONTROL MODULE (FPCM)
EC-403
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P1220 FUEL PUMP CONTROL MODULE (FPCM)
DTC LogicINFOID:0000000006217912
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
 Before performing the following procedure, confirm that battery voltage is between 12 - 15 V at idle.
 Before performing the following procedure, check that the engine coolant temperature is −10 °C
(14 °F) or more.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 5 seconds. If engine does not start, crank engine for at least 5 seconds.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-403, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217913
1.CHECK FPCM POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect FPCM harness connector.
3. Turn ignition switch ON.
4. Check the voltage between FPCM harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 3.
2.DETECT MALFUNCTIONING PART
Check the following.
 15 A fuse (No.73)
 Harness for open or short between FPCM and IPDM E/R
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1220 FPCM
(Fuel pump control module) During engine cranking, the signal voltage
of the FPCM to the ECM is too low.  Harness or connectors
(FPCM circuit is open or shorted)
(Fuel pump circuit is open or shorted)
FPCM
FPCM Ground Voltage
Connector Terminal
B41 10 Ground Battery voltage
Revision: 2010 May2011 QX56

EC-404
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1220 FUEL PUMP CONTROL MODULE (FPCM)
3.CHECK FPCM GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check the continuity between FPCM harness connector and ground.
3. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to power in harness or connectors.
4.CHECK FPCM INPUT AND OUTPUT CIRCUITS FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check the continuity between FPCM harness connector and ECM harness connector.
3. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between FPCM and ECM
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK FUEL PUMP CONTROL CIRCUIT FOR OPEN AND SHORT
1. Disconnect fuel level sensor unit and fuel pump harness connector.
2. Check the continuity between FPCM harness connecto r and fuel level sensor unit and fuel pump harness
connector.
3. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK FPCM
Refer to EC-405, "
Component Inspection (FPCM)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Replace FPCM.
FPCM Ground Continuity
Connector Terminal
B41 5 Ground Existed
FPCM ECM Continuity
Connector Terminal Connector Terminal
B41 8
E80 125
Existed
9142
FPCM Fuel level sensor unit and fuel pump Continuity
Connector Terminal Connector Terminal
B41 6
C5 3
Existed
71
Revision: 2010 May2011 QX56

EC-412
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1550 BATTERY CURRENT SENSOR
P1550 BATTERY CURRENT SENSOR
DTC LogicINFOID:0000000006217919
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is 8 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-412, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217920
1.CHECK BATTERY CURRENT SENSO R POWER SUPPLY CIRCUIT-I
1. Disconnect battery current sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between battery current sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 2.
2.CHECK BATTERY CURRENT SENSO R POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1550 BAT CURRENT SENSOR
(Battery current sensor cir-
cuit range/performance) The output voltage of the battery
current sensor remains within
the specified range while engine
is running.  Harness or connectors
(Battery current sensor circuit is open or shorted.)
(Accelerator pedal position sensor 2 circuit is shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Crankshaft position sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
(EVAP control system pressure sensor circuit is short-
ed.)
 Battery current sensor
 Accelerator pedal position sensor
 Camshaft position sensor (bank 1)
 Crankshaft position sensor
 Refrigerant pressure sensor
 EVAP control system pressure sensor
Battery current sensor Ground Voltage (V)
Connector Terminal
E63 2 Ground Approx. 5
Revision: 2010 May2011 QX56