Page 2323 of 3419
![INFINITI QX4 2005 Factory Service Manual LAN-44
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
Driver Seat Control Unit Circuit CheckUKS0018N
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery termi INFINITI QX4 2005 Factory Service Manual LAN-44
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
Driver Seat Control Unit Circuit CheckUKS0018N
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery termi](/manual-img/42/57035/w960_57035-2322.png)
LAN-44
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
Driver Seat Control Unit Circuit CheckUKS0018N
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 CheckUKS0018O
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
Page 2324 of 3419
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LAN-45
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Display Control Unit Circuit CheckUKS0018P
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the INFINITI QX4 2005 Factory Service Manual CAN SYSTEM (TYPE 1)
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Display Control Unit Circuit CheckUKS0018P
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the](/manual-img/42/57035/w960_57035-2323.png)
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Display Control Unit Circuit CheckUKS0018P
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 CheckUKS0018Q
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
Page 2325 of 3419
![INFINITI QX4 2005 Factory Service Manual LAN-46
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
Data Link Connector Circuit CheckUKS0018R
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
INFINITI QX4 2005 Factory Service Manual LAN-46
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
Data Link Connector Circuit CheckUKS0018R
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.](/manual-img/42/57035/w960_57035-2324.png)
LAN-46
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
Data Link Connector Circuit CheckUKS0018R
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-21, "Work Flow" .
NG >> Repair harness between data link connector and combi-
nation meter.
Steering Angle Sensor Circuit CheckUKS0018S
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
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Front Air Control Circuit CheckUKS0018T
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the ne INFINITI QX4 2005 Factory Service Manual CAN SYSTEM (TYPE 1)
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Front Air Control Circuit CheckUKS0018T
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the ne](/manual-img/42/57035/w960_57035-2325.png)
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Front Air Control Circuit CheckUKS0018T
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.
ABS Actuator and Electric Unit (Control Unit) Circuit CheckUKS0018U
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. 34 (L) - 35 (P) : Approx. 54 - 66 Ω
PKIA8136E
11 (L) - 15 (P) : Approx. 54 - 66 Ω
SKIA6872E
Page 2327 of 3419
![INFINITI QX4 2005 Factory Service Manual LAN-48
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
IPDM E/R Circuit CheckUKS0018V
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check te INFINITI QX4 2005 Factory Service Manual LAN-48
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
IPDM E/R Circuit CheckUKS0018V
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check te](/manual-img/42/57035/w960_57035-2326.png)
LAN-48
[CAN]
CAN SYSTEM (TYPE 1)
Revision: October 20052005 QX56
IPDM E/R Circuit CheckUKS0018V
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.
CAN Communication Circuit CheckUKS0018W
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
–ABS actuator and electric unit (control unit)
–IPDM E/R
OK or NG
OK >> GO TO 2.
NG >> Repair or replace as necessary.39 (L) - 40 (P) : Approx. 108 - 132 Ω
PKIA8141E
Page 2357 of 3419
LAN-78
[CAN]
CAN SYSTEM (TYPE 2)
Revision: October 20052005 QX56
Case 21
Check IPDM E/R ignition relay circuit continuously sticks “ON”. Refer to LAN-89, "IPDM E/R Ignition Relay Cir-
cuit Check" .
Circuit Check Between TCM and ICC SensorUKS001N8
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 (L), 8 (P) and harness connector F33 terminals 12
(L), 11 (P).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.
SKIB3476E
3 (L) - 12 (L) : Continuity should exist.
8 (P) - 11 (P) : Continuity should exist.
PKIA6831E
Page 2358 of 3419
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3. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ICC sensor connector.
2. Check continuity between harness co INFINITI QX4 2005 Factory Service Manual CAN SYSTEM (TYPE 2)
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3. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ICC sensor connector.
2. Check continuity between harness co](/manual-img/42/57035/w960_57035-2357.png)
CAN SYSTEM (TYPE 2)
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3. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ICC sensor connector.
2. Check continuity between harness connector E19 terminals 12
(L), 11 (P) and ICC sensor connector E42 terminals 2 (L), 3 (P).
OK or NG
OK >> Connect all connectors and diagnose again. Refer to
LAN-55, "
Work Flow" .
NG >> Repair harness.
Circuit Check Between ICC Sensor and ICC UnitUKS001PO
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 (L), 3 (P) and harness connector E34 terminals 24 (L), 23 (P).
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
(L), 23 (P) and ICC unit connector B13 terminals 14 (L), 5 (P).
OK or NG
OK >> Connect all connectors and diagnose again. Refer to
LAN-55, "
Work Flow" .
NG >> Repair harness.12 (L) - 2 (L) : Continuity should exist.
11 (P) - 3 (P) : Continuity should exist.
PKIA8171E
2 (L) - 24 (L) : Continuity should exist.
3 (P) - 23 (P) : Continuity should exist.
PKIA8137E
24 (L) - 14 (L) : Continuity should exist.
23 (P) - 5 (P) : Continuity should exist.
PKIA8138E
Page 2359 of 3419
![INFINITI QX4 2005 Factory Service Manual LAN-80
[CAN]
CAN SYSTEM (TYPE 2)
Revision: October 20052005 QX56
Circuit Check Between ICC Unit and Driver Seat Control UnitUKS001PP
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the n INFINITI QX4 2005 Factory Service Manual LAN-80
[CAN]
CAN SYSTEM (TYPE 2)
Revision: October 20052005 QX56
Circuit Check Between ICC Unit and Driver Seat Control UnitUKS001PP
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the n](/manual-img/42/57035/w960_57035-2358.png)
LAN-80
[CAN]
CAN SYSTEM (TYPE 2)
Revision: October 20052005 QX56
Circuit Check Between ICC Unit and Driver Seat Control UnitUKS001PP
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 connectors and diagnose again. Refer to
LAN-55, "
Work Flow" .
NG >> Repair harness.
Circuit Check Between Driver Seat Control Unit and Data Link ConnectorUKS001N9
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