ignition INFINITI QX56 2010 Factory Service Manual

EC-84
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POWER SUPPLY AND GROUND CIRCUIT
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
11 .CHECK ECM POWER SUPPLY CIRCUIT-VI
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminal 111 and IPDM E/R terminal 7. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 12.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
12.CHECK 20 A FUSE
1. Disconnect 20 A fuse from IPDM E/R.
2. Check 20 A fuse (No. 53).
OK or NG
OK >> GO TO 16.
NG >> Replace 20 A fuse.
13.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-85, "
Ground Inspection".
OK or NG
OK >> GO TO 14.
NG >> Repair or replace ground connections.
14.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground. Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 16.
NG >> GO TO 15.
15.DETECT MALFUNCTIONING PART Continuity should exist.
Continuity should exist.
BBIA0354E
Continuity should exist.
Revision: April 20092010 QX56

EC-86
< COMPONENT DIAGNOSIS >[VK56DE]
U0101 CAN COMM CIRCUIT
U0101 CAN COMM CIRCUIT
DescriptionINFOID:0000000005157950
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication s
peed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CA N communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
On Board Diagn osis LogicINFOID:0000000005157951
This self-diagnosis has the one trip detection logic.
DTC Confirmation ProcedureINFOID:0000000005157952
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check DTC.
3. If DTC is detected, go to EC-86, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005157953
Go to LAN-44, "CAN Communication Signal Chart".
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
U0101
0101 Lost communication with
TCM When ECM is not transmitting or receiving CAN
communication signal of OBD (emission-related
diagnosis) with TCM for 2 seconds or more. • CAN communication line between
TCM and ECM
(CAN communication line is open or
shorted)
Revision: April 20092010 QX56

U1001 CAN COMM CIRCUITEC-87
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U1001 CAN COMM CIRCUIT
DescriptionINFOID:0000000005149087
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each
control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
On Board Diagnosis LogicINFOID:0000000005149088
MIL will not illuminate for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000005149089
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-87, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149090
Go to LAN-44, "CAN Communication Signal Chart".
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
U1001
1001 CAN communication line When ECM is not transmitting or receiving CAN
communication signal other than OBD (emis-
sion related diagnosis) for 2 seconds or more. • Harness or connectors
(CAN communication line is open or
shorted)
Revision: April 20092010 QX56

EC-88
< COMPONENT DIAGNOSIS >[VK56DE]
P0011, P0021 IVT CONTROL
P0011, P0021 IVT CONTROL
On Board Diagn
osis LogicINFOID:0000000005149091
•If DTC P0011 or P0021 is displayed with DTC P 0075, P0081 first perform the trouble diagnosis for
DTC P0075, P0081. Refer to EC-101, "
DTC Confirmation Procedure".
• If DTC P0011 or P0021 is displayed with DTC P1140, P1145 first perform the trouble diagnosis for
DTC P1140, P1145. Refer to EC-295, "
DTC Confirmation Procedure".
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureINFOID:0000000005149092
CAUTION:
Always drive at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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 between 10 V and 16 V at
idle.
PROCEDURE FOR MALFUNCTION A
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Maintain the following conditions for at least 10 consecutive seconds.
DTC No. Trouble diagnosis name Detecting conditionPossible cause
P0011
0011
(Bank 1)
Intake valve timing control
performance A
The alignment of the intake valve timing
control has been misresistered. • Harness or connectors
(Intake valve timing control solenoid
valve circuit is open or shorted.)
• Harness or connectors
(Intake valve timing control position
sensor circuit is open or shorted.)
• Intake valve timing control solenoid valve
• Intake valve timing control position sensor
• Crankshaft position sensor (POS)
• Camshaft position sensor (PHASE)
• Accumulation of debris to the signal pick-up portion of the camshaft
sprocket
• Timing chain installation
• Foreign matter caught in the oil groove for intake valve timing control
P0021
0021
(Bank 2)
B
There is a gap between angle of target and
phase-control angle degree.
Detected items
Engine operating condition in fail-safe mode
Intake valve timing control The signal is not energized to the solenoid valve and the valve control does not function
ENG SPEEDMore than 2,000 rpm (A cons tant rotation is maintained.)
COOLAN TEMP/S More than 70 °C (158 °F)
Revision: April 20092010 QX56

P0011, P0021 IVT CONTROLEC-89
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5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to
EC-89, "
Diagnosis Procedure".
PROCEDURE FOR MALFUNCTION B
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Maintain the following conditions for at least 10 consecutive seconds.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-89, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005149093
1.CHECK OIL PRESSURE WARNING LAMP
1. Start engine.
2. Check oil pressure warning lamp and confirm it is not illumi- nated.
OK or NG
OK >> GO TO 2.
NG >> Go to LU-8, "
Inspection".
2.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Selector lever 1st or 2nd position
Driving location uphill Driving vehicle uphill
(Increased engine load will help maintain the driving con-
ditions required for this test.)
ENG SPEED Idle
COOLAN TEMP/S More than 70 °C (158 °F)
Selector lever P or N position
ENG SPEED1,700 - 3,175 rpm (A constant rotation is maintained.)
COOLAN TEMP/S More than 70 °C (158 °F)
Selector lever 1st or 2nd position
Driving location uphill Driving vehicle uphill
(Increased engine load will help maintain the driving con-
ditions required for this test.)
PBIA8559J
Revision: April 20092010 QX56

EC-90
< COMPONENT DIAGNOSIS >[VK56DE]
P0011, P0021 IVT CONTROL
Refer to EC-85, "Ground Inspection".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3.CHECK INTAKE VALVE TIMING CONTROL PO SITION SENSOR POWER SUPPLY CIRCUIT
1. Disconnect intake valve timing control position sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between intake valve timing control position sen- sor terminal 3 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• Harness for open or short between intake valve timing control position sensor and ECM
• Harness for open or short between intake valve timing control position sensor and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK INTAKE VALVE TIMING CONTROL POSI TION SENSOR GROUND CIRCUIT FOR OPEN AND
SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between intake valve timing control position sensor terminal 1 and ground.
Refer to Wiring Diagram.
BBIA0354E
1. Intake valve timing control position
sensor (bank 2) 2. Intake valve timing control solenoid
valve (bank 2) 3. Drive belt
4. Radiator hose 5. Intake valve timing control solenoid
valve (bank 1) 6. Intake valve timing control position
sensor (bank 1)
Voltage: Battery voltage
BBIA0771E
PBIB2613E
Revision: April 20092010 QX56

P0011, P0021 IVT CONTROLEC-91
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3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• Harness for open or short between intake valve timing control position sensor and ground
>> Repair open circuit or short to power in harness or connectors.
7.CHECK INTAKE VALVE TIMING CONTROL POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN
AND SHORT1. Disconnect ECM harness connector.
2. Check harness continuity between the following; ECM terminal 72 and intake valve timing control position sensor (Bank 1) terminal 2 or
ECM terminal 53 and intake valve timing contro l position sensor (Bank 2) terminal 2.
Refer to Wiring Diagram.
3. 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 INTAKE VALVE TIMING CONTROL POSITION SENSOR
Refer to EC-93, "
Component Inspection".
OK or NG
OK >> GO TO 9.
NG >> Replace malfunctioning intake valve timing control position sensor. Refer to EC-495
.
9.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Reconnect ECM harness connector.
2. Disconnect intake valve timing control solenoid valve harness connector.
3. Turn ignition switch ON. Continuity should exist.
Continuity should exist.
1. Intake valve timing control position
sensor (bank 2) 2. Intake valve timing control solenoid
valve (bank 2) 3. Drive belt
4. Radiator hose 5. Intake valve timing control solenoid
valve (bank 1) 6. Intake valve timing control position
sensor (bank 1)
BBIA0771E
Revision: April 20092010 QX56

EC-92
< COMPONENT DIAGNOSIS >[VK56DE]
P0011, P0021 IVT CONTROL
4. Check voltage between intake valve timing control solenoid
valve terminal 2 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• Harness for open or short between intake valv e timing control solenoid valve and IPDM E/R.
>> Repair open circuit or short to ground or short to power in harness or connectors.
11 .CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN
AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following; ECM terminal 10 and intake valve timing control solenoid valve (Bank 1) terminal 1 or
ECM terminal 11 and intake valve timing control solenoid valve (Bank 2) terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 12.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
12.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE
Refer to EC-93, "
Component Inspection".
OK or NG
OK >> GO TO 13.
NG >> Replace malfunctioning intake valve timing control solenoid valve. Refer to EC-494
.
13.CHECK CRANKSHAFT POSI TION SENSOR (POS)
Refer to EC-203, "
Component Inspection".
OK or NG
OK >> GO TO 14.
NG >> Replace crankshaft position sensor (POS).
14.CHECK CAMSHAFT POSITI ON SENSOR (PHASE)
Refer to EC-207, "
Component Inspection".
OK or NG
OK >> GO TO 15.
NG >> Replace malfunctioning camshaft position sensor (PHASE). Refer to EC-495
.
15.CHECK CAMSHAFT SPROCKET
Check accumulation of debris to the signal pick -up portion of the camshaft sprocket. Refer to EM-62, "
Inspec-
tion after Installation".
OK or NG
OK >> GO TO 16. Voltage: Battery voltage
PBIB0351E
Continuity should exist.
Revision: April 20092010 QX56

P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-95
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P0031, P0032, P0051, P0052
A/F SENSOR 1 HEATER
DescriptionINFOID:0000000005149095
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
On Board Diagnosis LogicINFOID:0000000005149096
DTC Confirmation ProcedureINFOID:0000000005149097
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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 between 10.5V and 16V at
idle.
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-95, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149098
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Sensor Input Signal to ECM ECM functionActuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Air fuel ratio (A/F) sensor 1
heater controlAir fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0031
0031
(Bank 1) Air fuel ratio (A/F) sensor
1 heater control circuit low The current amperage in the air fuel ratio (A/F) sen-
sor 1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.) • Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
• A/F sensor 1 heater
P0051
0051
(Bank 2)
P0032
0032
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit
high The current amperage in the air fuel ratio (A/F) sen-
sor 1 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.) • Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
• A/F sensor 1 heater
P0052
0052
(Bank 2)
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EC-96
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P0031, P0032, P0051, P00
52 A/F SENSOR 1 HEATER
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 air fuel ratio (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
• 15 A fuse (No. 54)
• Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
4.CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 2 (bank 1) or 24, 43 (bank 2) and A/F sensor 1 terminal
3.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
BBIA0354E
Voltage: Battery voltage
BBIA0376E
PBIB3308E
Continuity should exist.
Revision: April 20092010 QX56