ignition INFINITI QX4 2005 Factory Service Manual

LAN-158
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 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
(L), 5 (P) and driver seat control unit connector P2 terminals 3
(L), 19 (P).
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 (L), 19 (P) and harness connector B69 ter-
minals 51J (L), 52J (P).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.14 (L) - 3 (L) : Continuity should exist.
5 (P) - 19 (P) : Continuity should exist.
PKIA8139E
3 (L) - 51J (L) : Continuity should exist.
19 (P) - 52J (P) : Continuity should exist.
PKIA6841E

CAN SYSTEM (TYPE 4)
LAN-159
[CAN]
C
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LAN
Revision: October 20052005 QX56
3. CHECK HARNESS FOR OPEN CIRCUIT
Check continuity between harness connector M40 terminals 51J (L),
52J (P) and data link connector M22 terminals 6 (L), 14 (P).
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
(L), 14 (P) and harness connector M31 terminals 31G (L), 42G
(P).
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 (L), 42G (P) and IPDM E/R harness connector E122 termi-
nals 39 (L), 40 (P).
OK or NG
OK >> Connect all the connectors and diagnose again. Refer to
LAN-131, "
Work Flow" .
NG >> Repair harness.51J (L) - 6 (L) : Continuity should exist.
52J (P) - 14 (P) : Continuity should exist.
PKIA6834E
6 (L) - 31G (L) : Continuity should exist.
14 (P) - 42G (P) : Continuity should exist.
PKIA6835E
31G (L) - 39 (L) : Continuity should exist.
42G (P) - 40 (P) : Continuity should exist.
PKIA8140E

LAN-160
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 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 (L) and 86 (P).
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 (L) and 8 (P).
OK or NG
OK >> Replace control valve with TCM.
NG >> Repair harness between A/T assembly and harness
connector F33. 94 (L) - 86 (P) : Approx. 108 - 132 Ω
PKIA0816E
3 (L) - 8 (P) : Approx. 54 - 66 Ω
SKIA6866E

CAN SYSTEM (TYPE 4)
LAN-161
[CAN]
C
D
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B
LAN
Revision: October 20052005 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 (L) and 3 (P).
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 (L) and 5 (P).
OK or NG
OK >> Replace ICC unit.
NG >> Repair harness between ICC unit and harness connec-
tor B69. 2 (L) - 3 (P) : Approx. 54 - 66 Ω
PKIA8172E
14 (L) - 5 (P) : Approx. 54 - 66 Ω
SKIA6886E

LAN-162
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 QX56
Driver Seat Control Unit Circuit CheckUKS001NZ
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 unit side and
harness side).
–Driver seat control unit connector
–Harness connector P1
–Harness connector B37
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.
2. Check resistance between driver seat control unit harness con-
nector P2 terminals 3 (L) and 19 (P).
OK or NG
OK >> Replace driver seat control unit.
NG >> Repair harness between driver seat control unit and har-
ness connector B69.
Combination Meter Circuit CheckUKS001O0
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of combination meter for damage, bend and loose connection (meter side
and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect combination meter connector.
2. Check resistance between combination meter harness connec-
tor M24 terminals 11 (L) and 12 (P).
OK or NG
OK >> Replace combination meter.
NG >> Repair harness between combination meter and data
link connector. 3 (L) - 19 (P) : Approx. 54 - 66 Ω
PKIA6842E
11 (L) - 12 (P) : Approx. 54 - 66 Ω
PKIA6837E

CAN SYSTEM (TYPE 4)
LAN-163
[CAN]
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LAN
Revision: October 20052005 QX56
Display Control Unit Circuit CheckUKS001O1
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of display 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 display control unit connector.
2. Check resistance between display control unit harness connec-
tor M95 terminals 25 (L) and 26 (P).
OK or NG
OK >> Replace display control unit.
NG >> Repair harness between display control unit and data
link connector.
BCM Circuit CheckUKS001O2
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of BCM 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 BCM connector.
2. Check resistance between BCM harness connector M18 termi-
nals 39 (L) and 40 (P).
OK or NG
OK >> Replace BCM. Refer to BCS-20, "Removal and Installa-
tion of BCM" .
NG >> Repair harness between BCM and data link connector.25 (L) - 26 (P) : Approx. 54 - 66 Ω
SKIA6884E
39 (L) - 40 (P) : Approx. 54 - 66 Ω
SKIA6869E

LAN-164
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 QX56
Data Link Connector Circuit CheckUKS001O3
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of data link connector for damage, bend and loose connection (connector
side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
Check resistance between data link connector M22 terminals 6 (L)
and 14 (P).
OK or NG
OK >> Diagnose again. Refer to LAN-131, "Work Flow" .
NG >> Repair harness between data link connector and combi-
nation meter.
Steering Angle Sensor Circuit CheckUKS001O4
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of steering angle 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 steering angle sensor connector.
2. Check resistance between steering angle sensor harness con-
nector M47 terminals 3 (L) and 4 (P).
OK or NG
OK >> Replace steering angle sensor.
NG >> Repair harness between steering angle sensor and data
link connector. 6 (L) - 14 (P) : Approx. 54 - 66 Ω
PKIA2077E
3 (L) - 4 (P) : Approx. 54 - 66 Ω
PKIA6838E

CAN SYSTEM (TYPE 4)
LAN-165
[CAN]
C
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LAN
Revision: October 20052005 QX56
Front Air Control Circuit CheckUKS001O5
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 (L) and 35 (P).
OK or NG
OK >> Replace front air control.
NG >> Repair harness between front air control and data link
connector.
Transfer Control Unit Circuit CheckUKS001O6
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 (L) and 8 (P).
OK or NG
OK >> Replace transfer control unit.
NG >> Repair harness between transfer control unit and har-
ness connector E152. 34 (L) - 35 (P) : Approx. 54 - 66 Ω
PKIA8136E
7 (L) - 8 (P) : Approx. 54 - 66 Ω
PKIA6844E

LAN-166
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 QX56
ABS Actuator and Electric Unit (Control Unit) Circuit CheckUKS001O7
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 (L) and 15 (P).
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 CheckUKS001O8
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 (L) and 40 (P).
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair harness between IPDM E/R and harness con-
nector E152. 11 (L) - 15 (P) : Approx. 54 - 66 Ω
SKIA6872E
39 (L) - 40 (P) : Approx. 108 - 132 Ω
PKIA8141E

CAN SYSTEM (TYPE 4)
LAN-167
[CAN]
C
D
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F
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B
LAN
Revision: October 20052005 QX56
CAN Communication Circuit CheckUKS001O9
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
–ICC sensor
–ICC unit
–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 (L) and 14
(P).
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 (L),
14 (P) and ground.
OK or NG
OK >> Check ECM and IPDM E/R. Refer to LAN-168, "ECM/
IPDM E/R INTERNAL CIRCUIT INSPECTION" .
NG >> Repair harness.
IPDM E/R Ignition Relay Circuit CheckUKS001OA
Check the following. If no malfunction is found, replace the IPDM E/R.

IPDM E/R power supply circuit. Refer to PG-26, "IPDM E/R Power/Ground Circuit Inspection" . 6 (L) - 14 (P) : Continuity should not exist.
PKIA2077E
6 (L) - Ground : Continuity should not exist.
14 (P) - Ground : Continuity should not exist.
PKIA2079E