ignition INFINITI QX56 2004 Factory Service Manual

LAN-122
[CAN]
CAN SYSTEM (TYPE 3)
Revision: August 20072004 QX56
Front Air Control Circuit CheckUKS001A7
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of front air control for damage, bend and loose connection (unit side and
harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect front air control connector.
2. Check resistance between front air control harness connector
M50 terminals 34 (W) and 35 (R).
OK or NG
OK >> Replace front air control.
NG >> Repair harness between front air control and data link
connector.
Transfer Control Unit Circuit CheckUKS001A8
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of transfer control unit for damage, bend and loose connection (control
unit side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect transfer control unit connector.
2. Check resistance between transfer control unit harness connec-
tor E142 terminals 7 (W) and 8 (R).
OK or NG
OK >> Replace transfer control unit.
NG >> Repair harness between transfer control unit and har-
ness connector E152. 34 (W) - 35 (R) : Approx. 54 - 66Ω
PKIA8136E
7 (W) - 8 (R) : Approx. 54 - 66Ω
PKIA6844E

CAN SYSTEM (TYPE 3)
LAN-123
[CAN]
C
D
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LAN
Revision: August 20072004 QX56
ABS Actuator and Electric Unit (Control Unit) Circuit CheckUKS001A9
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of ABS actuator and electric unit (control unit) for damage, bend and loose
connection (control unit side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ABS actuator and electric unit (control unit) connector.
2. Check resistance between ABS actuator and electric unit (con-
trol unit) harness connector E125 terminals 11 (W) and 15 (R).
OK or NG
OK >> Replace ABS actuator and electric unit (control unit).
NG >> Repair harness between ABS actuator and electric unit
(control unit) and harness connector E152.
IPDM E/R Circuit CheckUKS001AA
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of IPDM E/R for damage, bend and loose connection (control module side
and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect IPDM E/R connector.
2. Check resistance between IPDM E/R harness connector E122
terminals 39 (W) and 40 (R).
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair harness between IPDM E/R and harness con-
nector E152. 11 (W) - 15 (R) : Approx. 54 - 66Ω
SKIA6872E
39 (W) - 40 (R) : Approx. 108 - 132Ω
PKIA8141E

LAN-124
[CAN]
CAN SYSTEM (TYPE 3)
Revision: August 20072004 QX56
CAN Communication Circuit CheckUKS001AB
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Disconnect the following module and control unit connectors and check terminals for deformation, discon-
nection, looseness or damage.
–ECM
–A/T assembly
–Driver seat control unit
–Combination meter
–Display control unit
–BCM
–Steering angle sensor
–Front air control
–Transfer control unit
–ABS actuator and electric unit (control unit)
–IPDM E/R
OK or NG
OK >> GO TO 2.
NG >> Repair or replace as necessary.
2. CHECK HARNESS FOR SHORT CIRCUIT
With all module and control unit connectors disconnected, check
continuity between data link connector M22 terminals 6 (W) and 14
(R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.
3. CHECK HARNESS FOR SHORT CIRCUIT
Check continuity between data link connector M22 terminals 6 (W),
14 (R) and ground.
OK or NG
OK >> Check ECM and IPDM E/R. Refer to LAN-125, "ECM/
IPDM E/R INTERNAL CIRCUIT INSPECTION" .
NG >> Repair harness.
IPDM E/R Ignition Relay Circuit CheckUKS001AC
Check the following. If no malfunction is found, replace the IPDM E/R.

IPDM E/R power supply circuit. Refer to PG-27, "IPDM E/R Power/Ground Circuit Inspection" .

Ignition power supply circuit. Refer to PG-13, "IGNITION POWER SUPPLY — IGNITION SW. IN ON
AND/OR START" . 6 (W) - 14 (R) : Continuity should not exist.
PKIA2077E
6 (W) - Ground : Continuity should not exist.
14 (R) - Ground : Continuity should not exist.
PKIA2079E

LAN-154
[CAN]
CAN SYSTEM (TYPE 4)
Revision: August 20072004 QX56
Case 20
Check CAN communication circuit. Refer to LAN-166, "CAN Communication Circuit Check" .
Case 21
Check IPDM E/R ignition relay circuit continuously sticks “OFF”. Refer to LAN-166, "IPDM E/R Ignition Relay
Circuit Check" .
PKIA8131E
PKIA8132E

CAN SYSTEM (TYPE 4)
LAN-155
[CAN]
C
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F
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LAN
Revision: August 20072004 QX56
Case 22
Check IPDM E/R ignition relay circuit continuously sticks “ON”. Refer to LAN-166, "IPDM E/R Ignition Relay
Circuit Check" .
Circuit Check Between TCM and ICC SensorUKS001NU
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check following terminals and connectors for damage, bend and loose connection (connector side and
harness side).
–Harness connector F33
–Harness connector E19
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect A/T assembly connector and harness connector F33.
2. Check continuity between A/T assembly harness connector F9
terminals 3 (W), 8 (R) and harness connector F33 terminals 12
(W), 11 (R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.
PKIA8133E
3 (W) - 12 (W) : Continuity should exist.
8 (R) - 11 (R) : Continuity should exist.
PKIA6831E

LAN-156
[CAN]
CAN SYSTEM (TYPE 4)
Revision: August 20072004 QX56
3. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ICC sensor connector.
2. Check continuity between harness connector E19 terminals 12
(W), 11 (R) and ICC sensor connector E42 terminals 2 (W), 3
(R).
OK or NG
OK >> Connect all connectors and diagnose again. Refer to
LAN-131, "
Work Flow" .
NG >> Repair harness.
Circuit Check Between ICC Sensor and ICC UnitUKS001PS
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check following terminals and connectors for damage, bend and loose connection (connector side and
harness side).
–Harness connector E34
–Harness connector B40
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ICC sensor connector and harness connector E34.
2. Check continuity between ICC sensor connector E42 terminals
2 (W), 3 (R) and harness connector E34 terminals 24 (W), 23
(R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.
3. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ICC unit connector.
2. Check continuity between harness connector B40 terminals 24
(W), 23 (R) and ICC unit connector B13 terminals 14 (W), 5 (R).
OK or NG
OK >> Connect all the connectors and diagnose again. Refer to
LAN-131, "
Work Flow" .
NG >> Repair harness.12 (W) - 2 (W) : Continuity should exist.
11 (R) - 3 (R) : Continuity should exist.
PKIA8171E
2 (W) - 24 (W) : Continuity should exist.
3 (R) - 23 (R) : Continuity should exist.
PKIA8137E
24 (W) - 14 (W) : Continuity should exist.
23 (R) - 5 (R) : Continuity should exist.
PKIA8138E

CAN SYSTEM (TYPE 4)
LAN-157
[CAN]
C
D
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F
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LAN
Revision: August 20072004 QX56
Circuit Check Between ICC Unit and Driver Seat Control UnitUKS001PT
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Disconnect ICC unit connector and driver seat control unit connector.
4. Check continuity between ICC unit connector B13 terminals 14
(W), 5 (R) and driver seat control unit connector P2 terminals 3
(W), 19 (R).
OK or NG
OK >> Connect all the connectors and diagnose again. Refer to
LAN-131, "
Work Flow" .
NG >> Repair harness.
Circuit Check Between Driver Seat Control Unit and Data Link ConnectorUKS001NV
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check following terminals and connectors for damage, bend and loose connection (connector side and
harness side).
–Harness connector B69
–Harness connector M40
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect driver seat control unit connector and harness connector B69.
2. Check continuity between driver seat control unit harness con-
nector P2 terminals 3 (W), 19 (R) and harness connector B69
terminals 51J (W), 52J (R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.14 (W) - 3 (W) : Continuity should exist.
5 (R) - 19 (R) : Continuity should exist.
PKIA8139E
3 (W) - 51J (W) : Continuity should exist.
19 (R) - 52J (R) : Continuity should exist.
PKIA6841E

LAN-158
[CAN]
CAN SYSTEM (TYPE 4)
Revision: August 20072004 QX56
3. CHECK HARNESS FOR OPEN CIRCUIT
Check continuity between harness connector M40 terminals 51J
(W), 52J (R) and data link connector M22 terminals 6 (W), 14 (R).
OK or NG
OK >> Connect all the connectors and diagnose again. Refer to
LAN-131, "
Work Flow" .
NG >> Repair harness.
Circuit Check Between Data Link Connector and IPDM E/RUKS001NW
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check following terminals and connectors for damage, bend and loose connection (connector side and
harness side).
–Harness connector M31
–Harness connector E152
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect harness connector M31.
2. Check continuity between data link connector M22 terminals 6
(W), 14 (R) and harness connector M31 terminals 31G (W), 42G
(R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.
3. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect IPDM E/R connector.
2. Check continuity between harness connector E152 terminals
31G (W), 42G (R) and IPDM E/R harness connector E122 termi-
nals 39 (W), 40 (R).
OK or NG
OK >> Connect all the connectors and diagnose again. Refer to
LAN-131, "
Work Flow" .
NG >> Repair harness.51J (W) - 6 (W) : Continuity should exist.
52J (R) - 14 (R) : Continuity should exist.
PKIA6834E
6 (W) - 31G (W) : Continuity should exist.
14 (R) - 42G (R) : Continuity should exist.
PKIA6835E
31G (W) - 39 (W) : Continuity should exist.
42G (R) - 40 (R) : Continuity should exist.
PKIA8140E

CAN SYSTEM (TYPE 4)
LAN-159
[CAN]
C
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LAN
Revision: August 20072004 QX56
ECM Circuit CheckUKS001NX
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check following terminals and connectors for damage, bend and loose connection (control module side
and harness side).
–ECM connector
–Harness connector E19
–Harness connector F33
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ECM connector.
2. Check resistance between ECM harness connector E16 termi-
nals 94 (W) and 86 (R).
OK or NG
OK >> Replace ECM.
NG >> Repair harness between ECM and A/T assembly.
TCM Circuit CheckUKS001NY
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of A/T assembly for damage, bend and loose connection (control module
side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect A/T assembly connector.
2. Check resistance between A/T assembly harness connector F9
terminals 3 (W) and 8 (R).
OK or NG
OK >> Replace control valve with TCM.
NG >> Repair harness between A/T assembly and harness
connector F33. 94 (W) - 86 (R) : Approx. 108 - 132Ω
PKIA0816E
3 (W) - 8 (R) : Approx. 54 - 66Ω
SKIA6866E

LAN-160
[CAN]
CAN SYSTEM (TYPE 4)
Revision: August 20072004 QX56
ICC Sensor Circuit CheckUKS001PU
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of ICC sensor for damage, bend and loose connection (sensor side and
harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ICC sensor connector.
2. Check resistance between ICC sensor harness connector E42
terminals 2 (W) and 3 (R).
OK or NG
OK >> Replace ICC sensor.
NG >> Repair harness between ICC sensor and harness con-
nector E34.
ICC Unit Circuit CheckUKS001PV
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of ICC unit for damage, bend and loose connection (control unit side and
harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ICC unit connector.
2. Check resistance between ICC unit harness connector B13 ter-
minals 14 (W) and 5 (R).
OK or NG
OK >> Replace ICC unit.
NG >> Repair harness between ICC unit and harness connec-
tor B69. 2 (W) - 3 (R) : Approx. 54 - 66Ω
PKIA8172E
14 (W) - 5 (R) : Approx. 54 - 66Ω
SKIA6886E