service INFINITI QX56 2007 Factory Service Manual

LAN-68
< SERVICE INFORMATION >[CAN]
TROUBLE DIAGNOSIS
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the A/T assembly for damage, bend and loose connection (unit
side and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of A/T assembly.
2. Check the resistance between the A/T assembly harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the TCM branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the TCM. Refer to AT-51, "
Circuit Diagram".
OK or NG
OK >> • Present error: Replace the TCM.
• Past error: Error was detected in the TCM branch line.
NG >> Repair the power supply and the ground circuit.
ICC Sensor Branch Line CircuitINFOID:0000000003533648
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the ICC sensor for damage, bend and loose connection (unit side
and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of ICC sensor.
2. Check the resistance between the ICC sensor harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the ICC sensor branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the ICC sensor. Refer to ACS-19, "
Schematic".
OK or NG
OK >> • Present error: Replace the ICC sensor. Refer to ACS-55, "ICC Sensor".
A/T assembly harness connector
Resistance (Ω)
Connector No. Terminal No.
F9 3 8 Approx. 54 – 66
ICC sensor harness connector
Resistance (Ω)
Connector No. Terminal No.
E42 2 3 Approx. 54 – 66

TROUBLE DIAGNOSIS
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• Past error: Error was detected in the ICC sensor branch line.
NG >> Repair the power supply and the ground circuit.
ICC Unit Branch Line CircuitINFOID:0000000003533649
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the ICC unit for damage, bend and loose connection (unit side and
connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of ICC unit.
2. Check the resistance between the ICC unit harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the ICC unit branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the ICC unit. Refer to ACS-19, "
Schematic".
OK or NG
OK >> • Present error: Replace the ICC unit. Refer to ACS-55, "ICC Unit".
• Past error: Error was detected in the ICC unit branch line.
NG >> Repair the power supply and the ground circuit.
Driver Seat Control Unit Branch Line CircuitINFOID:0000000003533650
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the following terminals and connectors for damage, bend and loose connection (unit side and con-
nector side).
- Driver seat control unit connector
- Harness connector P1
- Harness connector B37
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of driver seat control unit.
2. Check the resistance between the driver seat control unit harness connector terminals.
ICC unit harness connector
Resistance (Ω)
Connector No. Terminal No.
B13 14 5 Approx. 54 – 66
Driver seat control unit harness connector
Resistance (Ω)
Connector No. Terminal No.
P2 3 19 Approx. 54 – 66

LAN-70
< SERVICE INFORMATION >[CAN]
TROUBLE DIAGNOSIS
OK or NG
OK >> GO TO 3.
NG >> Repair the driver seat control unit branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the driver seat control unit. Refer to SE-13, "
Schematic".
OK or NG
OK >> • Present error: Replace the driver seat control unit. Refer to SE-74, "Removal and Installation".
• Past error: Error was detected in the driver seat control unit branch line.
NG >> Repair the power supply and the ground circuit.
BCM Branch Line CircuitINFOID:0000000003533651
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the BCM for damage, bend and loose connection (unit side and
connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of BCM.
2. Check the resistance between the BCM harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the BCM branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the BCM. Refer to BCS-8, "
Schematic".
OK or NG
OK >> • Present error: Replace the BCM. Refer to BCS-24, "BCM".
• Past error: Error was detected in the BCM branch line.
NG >> Repair the power supply and the ground circuit.
Display Control Unit Branch Line CircuitINFOID:0000000003533652
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the display control unit for damage, bend and loose connection
(unit side and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of display control unit.
BCM harness connector
Resistance (Ω)
Connector No. Terminal No.
M18 39 40 Approx. 54 – 66

TROUBLE DIAGNOSIS
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2. Check the resistance between the display control unit harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the display control unit branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the display control unit. Refer to AV-85, "
Schematic".
OK or NG
OK >> • Present error: Replace the display control unit. Refer to AV-145, "Removal and Installation".
• Past error: Error was detected in the display control unit branch line.
NG >> Repair the power supply and the ground circuit.
Data Link Connector Branch Line CircuitINFOID:0000000003533653
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the data link connector for damage, bend and loose connection
(connector side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
Check the resistance between the data link connector terminals.
OK or NG
OK >> • Present error: Check the following items again.
- Decision of CAN system type.
- Not received CONSULT-II data (SELECT SYSTEM, SELF-DIAG RESULTS, CAN DIAG SUP-
PORT MNTR).
- Not copied from on-board diagnosis.
- Procedure for detecting root cause.
• Past error: Error was detected in the data link connector branch line circuit.
NG >> Repair the data link connector branch line.
Front Air Control Branch Line CircuitINFOID:0000000003533654
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the front air control for damage, bend and loose connection (unit
side and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
Display control unit harness connector
Resistance (Ω)
Connector No. Terminal No.
M95 25 26 Approx. 54 – 66
Data link connector
Resistance (Ω)
Connector No. Terminal No.
M22 6 14 Approx. 54 – 66

LAN-72
< SERVICE INFORMATION >[CAN]
TROUBLE DIAGNOSIS
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of front air control.
2. Check the resistance between the front air control harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the front air control branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the front air control. Refer to ATC-36, "
Schematic".
OK or NG
OK >> • Present error: Replace the front air control. Refer to ATC-123, "Removal and Installation".
• Past error: Error was detected in the front air control branch line.
NG >> Repair the power supply and the ground circuit.
Combination Meter Branch Line CircuitINFOID:0000000003533655
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the combination meter for damage, bend and loose connection
(unit side and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of combination meter.
2. Check the resistance between the combination meter harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the combination meter branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the combination meter. Refer to DI-9, "
Wiring Diagram -
METER -".
OK or NG
OK >> • Present error: Replace the combination meter. Refer to IP-10, "Removal and Installation".
• Past error: Error was detected in the combination meter branch line.
NG >> Repair the power supply and the ground circuit.
Steering Angle Sensor Branch Line CircuitINFOID:0000000003533656
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
Front air control harness connector
Resistance (Ω)
Connector No. Terminal No.
M50 34 35 Approx. 54 – 66
Combination meter harness connector
Resistance (Ω)
Connector No. Terminal No.
M24 11 12 Approx. 54 – 66

TROUBLE DIAGNOSIS
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2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the steering angle sensor for damage, bend and loose connection
(unit side and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of steering angle sensor.
2. Check the resistance between the steering angle sensor harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the steering angle sensor branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the steering angle sensor. Refer to BRC-15, "
Schematic".
OK or NG
OK >> • Present error: Replace the steering angle sensor. Refer to BRC-60, "Removal and Installation".
• Past error: Error was detected in the steering angle sensor branch line.
NG >> Repair the power supply and the ground circuit.
Transfer Control Unit Branch Line CircuitINFOID:0000000003533657
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the transfer control unit for damage, bend and loose connection
(unit side and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of transfer control unit.
2. Check the resistance between the transfer control unit harness connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Repair the transfer control unit branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the transfer control unit. Refer to TF-23, "
Circuit Diagram".
OK or NG
OK >> • Present error: Replace the transfer control unit. Refer to TF-115, "Removal and Installation".
• Past error: Error was detected in the transfer control unit branch line.
NG >> Repair the power supply and the ground circuit.
Steering angle sensor harness connector
Resistance (Ω)
Connector No. Terminal No.
M47 3 4 Approx. 54 – 66
Transfer control unit harness connector
Resistance (Ω)
Connector No. Terminal No.
E142 7 8 Approx. 54 – 66

LAN-74
< SERVICE INFORMATION >[CAN]
TROUBLE DIAGNOSIS
ABS Actuator and Electric Unit (Control Unit) Branch Line Circuit
INFOID:0000000003533658
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the ABS actuator and electric unit (control unit) for damage, bend
and loose connection (unit side and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of ABS actuator and electric unit (control unit).
2. Check the resistance between the ABS actuator and electric unit (control unit) harness connector termi-
nals.
OK or NG
OK >> GO TO 3.
NG >> Repair the ABS actuator and electric unit (control unit) branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the ABS actuator and electric unit (control unit). Refer to
BRC-15, "
Schematic".
OK or NG
OK >> • Present error: Replace the ABS actuator and electric unit (control unit). Refer to BRC-58,
"Removal and Installation".
• Past error: Error was detected in the ABS actuator and electric unit (control unit) branch line.
NG >> Repair the power supply and the ground circuit.
IPDM E/R Branch Line CircuitINFOID:0000000003533659
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the IPDM E/R for damage, bend and loose connection (unit side
and connector side).
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of IPDM E/R.
2. Check the resistance between the IPDM E/R harness connector terminals.
OK or NG
OK >> GO TO 3.
ABS actuator and electric unit (control unit) harness connector
Resistance (Ω)
Connector No. Terminal No.
E125 11 15 Approx. 54 – 66
IPDM E/R harness connector
Resistance (Ω)
Connector No. Terminal No.
E122 39 40 Approx. 108 – 132

TROUBLE DIAGNOSIS
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NG >> Repair the IPDM E/R branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the IPDM E/R. Refer to PG-3, "
Schematic".
OK or NG
OK >> • Present error: Replace the IPDM E/R. Refer to PG-28, "Removal and Installation of IPDM E/R".
• Past error: Error was detected in the IPDM E/R branch line.
NG >> Repair the power supply and the ground circuit.
CAN Communication CircuitINFOID:0000000003533660
INSPECTION PROCEDURE
1.CONNECTOR INSPECTION
1. Turn the ignition switch OFF
2. Disconnect the battery cable from the negative terminal.
3. Disconnect all the unit connectors on CAN communication system.
4. Check terminals and connectors for damage, bend and loose connection.
OK or NG
OK >> GO TO 2.
NG >> Repair the terminal and connector.
2.CHECK HARNESS CONTINUITY (SHORT CIRCUIT)
Check the continuity between the data link connector terminals.
OK or NG
OK >> GO TO 3.
NG >> Check the harness and repair the root cause.
3.CHECK HARNESS CONTINUITY (SHORT CIRCUIT)
Check the continuity between the data link connector and the ground.
OK or NG
OK >> GO TO 4.
NG >> Check the harness and repair the root cause.
4.CHECK ECM AND IPDM E/R TERMINATION CIRCUIT
1. Remove the ECM and the IPDM E/R.
2. Check the resistance between the ECM terminals.
3. Check the resistance between the IPDM E/R terminals.
Data link connector
Continuity
Connector No. Terminal No.
M22 6 14 No
Data link connector
GroundContinuity
Connector No. Terminal No.
M226No
14 No
ECM
Resistance (Ω)
Te r m i n a l N o .
94 86 Approx. 108 – 132
LKIA0037E

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TROUBLE DIAGNOSIS
OK or NG
OK >> GO TO 5.
NG >> Replace the ECM and/or the IPDM E/R.
5.CHECK SYMPTOM
Connect all the connectors. Check if the symptoms described in the “Symptom (Results from interview with
customer)” are reproduced.
Inspection result
Reproduced>>GO TO 6.
Non-reproduced>>Start the diagnosis again. Follow the trouble diagnosis procedure when past error is
detected.
6.CHECK UNIT REPRODUCTION
Perform the reproduction test as per the following procedure for each unit.
1. Turn the ignition switch OFF
2. Disconnect the battery cable from the negative terminal.
3. Disconnect all the unit connectors on CAN communication system.
NOTE:
ECM and IPDM E/R have a termination circuit. Check other units first.
4. Connect the battery cable to the negative terminal. Check if the symptoms described in the “Symptom
(Results from interview with customer)” are reproduced.
NOTE:
Although unit-related error symptoms occur, do not confuse them with other symptoms.
Inspection result
Reproduced>>Connect the connector. Check other units as per the above procedure.
Non-reproduced>>Replace unit whose connector was disconnected.
IPDM E/R
Resistance (Ω)
Te r m i n a l N o .
39 40 Approx. 108 – 132

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CONTENTS
LIGHTING SYSTEM
SERVICE INFORMATION ............................4
PRECAUTIONS ...................................................4
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
4
General precautions for service operations ..............4
HEADLAMP (FOR USA) .....................................5
Component Parts and Harness Connector Loca-
tion ............................................................................
5
System Description ...................................................5
CAN Communication System Description .................7
Schematic .................................................................7
Wiring Diagram - H/LAMP - .......................................8
Terminal and Reference Value for BCM .................11
Terminal and Reference Value for IPDM E/R .........11
How to Proceed with Trouble Diagnosis .................12
Preliminary Check ...................................................12
CONSULT-II Function (BCM) ..................................12
CONSULT-II Function (IPDM E/R) ..........................13
Headlamp HI Does Not Illuminate (Both Sides) ......14
Headlamp HI Does Not Illuminate (One Side) ........15
High Beam Indicator Lamp Does Not Illuminate .....16
Headlamp LO Does Not Illuminate (Both Sides) .....17
Headlamp LO Does Not Illuminate (One Side) .......18
Headlamps Do Not Turn OFF .................................19
Aiming Adjustment ..................................................20
Bulb Replacement ...................................................21
Removal and Installation .........................................22
Disassembly and Assembly ....................................23
HEADLAMP (FOR CANADA) - DAYTIME
LIGHT SYSTEM - ...............................................
24
Component Parts and Harness Connector Loca-
tion ..........................................................................
24
System Description .................................................24
CAN Communication System Description ...............25
Schematic ...............................................................26
Wiring Diagram - DTRL - .........................................27
Terminal and Reference Value for BCM .................30
How to Proceed with Trouble Diagnosis ..................30
Preliminary Check ...................................................31
CONSULT-II Function for BCM ...............................32
CONSULT-II Function for IPDM E/R .......................32
Daytime Light Control Does Not Operate Properly
(Normal Headlamps Operate Properly) ...................
32
Aiming Adjustment ...................................................33
Bulb Replacement ...................................................33
Removal and Installation .........................................33
Disassembly and Assembly .....................................33
AUTO LIGHT SYSTEM .....................................34
Component Parts and Harness Connector Loca-
tion ...........................................................................
34
System Description ..................................................34
CAN Communication System Description ...............35
Major Component and Functions ............................35
Schematic ................................................................36
Wiring Diagram - AUTO/L - .....................................37
Terminal and Reference Value for BCM ..................39
Terminal and Reference Value for IPDM E/R ..........39
How to Proceed with Trouble Diagnosis ..................40
Preliminary Check ...................................................40
CONSULT-II Function (BCM) ..................................40
CONSULT-II Function (IPDM E/R) ..........................41
Trouble Diagnosis Chart by Symptom .....................42
Lighting Switch Inspection .......................................42
Optical Sensor System Inspection ...........................43
Optical Sensor .........................................................44
HEADLAMP AIMING CONTROL ......................45
System Description ..................................................45
Wiring Diagram - H/AIM - ........................................46
Headlamp Aiming Switch .........................................47
Switch Circuit Inspection .........................................48
FRONT FOG LAMP ..........................................49
Component Parts and Harness Connector Loca-
tion ...........................................................................
49
System Description ..................................................49
CAN Communication System Description ...............50