ignition INFINITI QX56 2008 Factory Service Manual

LAN
DLC BRANCH LINE CIRCUITLAN-77
< COMPONENT DIAGNOSIS > [CAN]
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DLC BRANCH LINE CIRCUIT
Diagnosis ProcedureINFOID:0000000001282422
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cabl e 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).
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
Check the resistance between the data link connector terminals.
Is the measurement value within the specification?
YES (Present error)>>Check the following items again.
• Decision of CAN system type.
• Not received CONSULT-III data [SELF-DIAG RESULTS, CAN DIAG SUPPORT MNTR (“ECU
list” included)].
• Procedure for detecting root cause.
YES (Past error)>>Error was detected in the data link connector branch line circuit.
NO >> Repair the data link connector branch line.
Data link connector Resistance (Ω)
Connector No. Terminal No.
M22 614Approx. 54 – 66
Revision: March 2010 2008 QX56

LAN-78
< COMPONENT DIAGNOSIS >[CAN]
HVAC BRANCH LINE CIRCUIT
HVAC BRANCH LINE CIRCUIT
Diagnosis ProcedureINFOID:0000000001282424
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/C auto amp. for damage, bend and loose connection (unit
side and connector side).
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of A/C auto amp.
2. Check the resistance between the A/C auto amp. harness connector terminals.
Is the measurement value within the specification?
YES >> GO TO 3.
NO >> Repair the A/C auto amp. branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the A/C auto amp. Refer to HAC-89, "
A/C Auto Amp Power
and Ground Diagnosis Procedure".
Is the inspection result normal?
YES (Present error)>>Replace the A/C auto amp. Refer to VTL-7, "Removal and Installation".
YES (Past error)>>Error was detect ed in the A/C auto amp. branch line.
NO >> Repair the power supply and the ground circuit.
A/C auto amp. harness connector Resistance (Ω)
Connector No. Terminal No.
M50 4140Approx. 54 – 66
Revision: March 2010 2008 QX56

LAN
I-KEY BRANCH LINE CIRCUITLAN-79
< COMPONENT DIAGNOSIS > [CAN]
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I-KEY BRANCH LINE CIRCUIT
Diagnosis ProcedureINFOID:0000000001282452
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cabl e from the negative terminal.
3. Check the terminals and connectors of the Intelligent Key unit for damage, bend and loose connection (unit side and connector side).
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of Intelligent Key unit.
2. Check the resistance between the Intelli gent Key unit harness connector terminals.
Is the measurement value within the specification?
YES >> GO TO 3.
NO >> Repair the Intelligent Key unit branch line.
3.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the Intelligent Key unit. Refer to DLK-64, "
INTELLIGENT
KEY UNIT : Diagnosis Procedure".
Is the inspection result normal?
YES (Present error)>>Replace the Intelligent Key unit.
YES (Past error)>>Error was detected in the Intelligent Key unit branch line.
NO >> Repair the power supply and the ground circuit.
Intelligent Key unit harness connector Resistance (Ω)
Connector No. Terminal No.
M70 2 3 Approx. 54 – 66
Revision: March 2010 2008 QX56

LAN-80
< COMPONENT DIAGNOSIS >[CAN]
M&A BRANCH LINE CIRCUIT
M&A BRANCH LINE CIRCUIT
Diagnosis ProcedureINFOID:0000000001282425
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 connecto rs of the combination meter for damage, bend and loose connection
(unit side and connector side).
Is the inspection result normal?
YES >> GO TO 2.
NO >> 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.
Is the measurement value within the specification?
YES >> GO TO 3.
NO >> 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 MWI-30, "
COMBINATION
METER : Diagnosis Procedure".
Is the inspection result normal?
YES (Present error)>>Replace the combination meter. Refer to MWI-76, "Removal and Installation".
YES (Past error)>>Error was detected in the combination meter branch line.
NO >> Repair the power supply and the ground circuit.
Combination meter harness connector Resistance (Ω)
Connector No. Terminal No.
M24 1011Approx. 54 – 66
Revision: March 2010 2008 QX56

LAN
STRG BRANCH LINE CIRCUITLAN-81
< COMPONENT DIAGNOSIS > [CAN]
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STRG BRANCH
LINE CIRCUIT
Diagnosis ProcedureINFOID:0000000001282426
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cabl e from the negative terminal.
3. Check the terminals and connectors of the steer ing angle sensor for damage, bend and loose connection
(unit side and connector side).
Is the inspection result normal?
YES >> GO TO 2.
NO >> 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.
Is the measurement value within the specification?
YES >> GO TO 3.
NO >> 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-61, "
Diagnosis Pro-
cedure".
Is the inspection result normal?
YES (Present error)>>Replace the steering angle sensor. Refer to BRC-118, "Removal and Installation".
YES (Past error)>>Error was detected in the steering angle sensor branch line.
NO >> Repair the power supply and the ground circuit.
Steering angle sensor harness connector Resistance (Ω)
Connector No. Terminal No.
M17 4 5 Approx. 54 – 66
Revision: March 2010 2008 QX56

LAN-82
< COMPONENT DIAGNOSIS >[CAN]
4WD BRANCH LINE CIRCUIT
4WD BRANCH LINE CIRCUIT
Diagnosis ProcedureINFOID:0000000001282427
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 connector for damage, bend and loose connection (unit side and connector side).
Is the inspection result normal?
YES >> GO TO 2.
NO >> 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.
Is the measurement value within the specification?
YES >> GO TO 3.
NO >> 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 DLN-22, "
Diagnosis Proce-
dure".
Is the inspection result normal?
YES (Present error)>>Replace the transfer control unit. Refer to DLN-128, "Removal and Installation".
YES (Past error)>>Error was detected in the transfer control unit branch line.
NO >> Repair the power supply and the ground circuit.
Transfer control unit harness connector Resistance (Ω)
Connector No. Terminal No.
E142 78Approx. 54 – 66
Revision: March 2010 2008 QX56

LAN
ABS BRANCH LINE CIRCUITLAN-83
< COMPONENT DIAGNOSIS > [CAN]
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ABS BRANCH LINE CIRCUIT
Diagnosis ProcedureINFOID:0000000001282428
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cabl e from the negative terminal.
3. Check the terminals and connectors of the ABS act uator and electric unit (control unit) for damage, bend
and loose connection (unit side and connector side).
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair the terminal and connector.
2.CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect the connector of ABS actuat or and electric unit (control unit).
2. Check the resistance between the ABS actuator and electric unit (control unit) harness connector termi-
nals.
Is the measurement value within the specification?
YES >> GO TO 3.
NO >> 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 A BS actuator and electric unit (control unit). Refer to
BRC-35, "
Diagnosis Procedure".
Is the inspection result normal?
YES (Present error)>>Replace the ABS actuator and electric unit (control unit). Refer to BRC-116, "Removal
and Installation".
YES (Past error)>>Error was detected in the ABS actuator and electric unit (control unit) branch line.
NO >> Repair the power supply and the ground circuit.
ABS actuator and electric unit (control unit) harness connector Resistance (Ω)
Connector No. Terminal No.
E125 1115Approx. 54 – 66
Revision: March 2010 2008 QX56

LAN-84
< COMPONENT DIAGNOSIS >[CAN]
IPDM-E BRANCH LINE CIRCUIT
IPDM-E BRANCH LINE CIRCUIT
Diagnosis ProcedureINFOID:0000000001282429
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).
Is the inspection result normal?
YES >> GO TO 2.
NO >> 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.
Is the measurement value within the specification?
YES >> GO TO 3.
NO >> 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 PCS-18, "
Diagnosis Procedure".
Is the inspection result normal?
YES (Present error)>>Replace the IPDM E/R. Refer to PCS-34, "Removal and Installation of IPDM E/R".
YES (Past error)>>Error was detected in the IPDM E/R branch line.
NO >> Repair the power supply and the ground circuit.
IPDM E/R harness connector Resistance (Ω)
Connector No. Terminal No.
E122 3940Approx. 108 – 132
Revision: March 2010 2008 QX56

LAN
CAN COMMUNICATION CIRCUITLAN-85
< COMPONENT DIAGNOSIS > [CAN]
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CAN COMMUNICATION CIRCUIT
Diagnosis ProcedureINFOID:0000000001282430
1.CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the battery cabl e 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.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair the terminal and connector.
2.CHECK HARNESS CONTINUI TY (SHORT CIRCUIT)
Check the continuity between the data link connector terminals.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Check the harness and repair the root cause.
3.CHECK HARNESS CONTINUI TY (SHORT CIRCUIT)
Check the continuity between the data link connector and the ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> 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.
Is the measurement value within the specification?
YES >> GO TO 5.
NO >> Replace the ECM and/or the IPDM E/R.
5.CHECK SYMPTOM
Connect all the connectors. Check if the symptoms descr ibed in the “Symptom (Results from interview with
customer)” are reproduced.
Data link connector Continuity
Connector No. Terminal No.
M22 6 14 Not existed
Data link connector
GroundContinuity
Connector No. Terminal No.
M22 6
Not existed
14 Not existed
ECM
Resistance (Ω)
Te r m i n a l N o .
94 86 Approx. 108 – 132
IPDM E/R Resistance (Ω)
Te r m i n a l N o .
39 40Approx. 108 – 132
LKIA0037E
Revision: March 2010 2008 QX56

LAN-86
< COMPONENT DIAGNOSIS >[CAN]
CAN COMMUNICATION CIRCUIT
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 one of the unit connectors of 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 the unit whose connector was disconnected.
Revision: March 2010 2008 QX56