Air INFINITI QX56 2004 Factory Service Manual

CAN SYSTEM (TYPE 2)
LAN-87
[CAN]
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Revision: August 20072004 QX56
Front Air Control Circuit CheckUKS001NJ
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.
ABS Actuator and Electric Unit (Control Unit) Circuit CheckUKS001NK
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. 34 (W) - 35 (R) : Approx. 54 - 66Ω
PKIA8136E
11 (W) - 15 (R) : Approx. 54 - 66Ω
SKIA6872E

LAN-88
[CAN]
CAN SYSTEM (TYPE 2)
Revision: August 20072004 QX56
IPDM E/R Circuit CheckUKS001NL
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.
CAN Communication Circuit CheckUKS001NM
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
–ABS actuator and electric unit (control unit)
–IPDM E/R
OK or NG
OK >> GO TO 2.
NG >> Repair or replace as necessary.39 (W) - 40 (R) : Approx. 108 - 132Ω
PKIA8141E

CAN SYSTEM (TYPE 2)
LAN-89
[CAN]
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LAN
Revision: August 20072004 QX56
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-89, "ECM/
IPDM E/R INTERNAL CIRCUIT INSPECTION" .
NG >> Repair harness.
IPDM E/R Ignition Relay Circuit CheckUKS001NN
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" .
Component InspectionUKS001NO
ECM/IPDM E/R INTERNAL CIRCUIT INSPECTION

Remove ECM and IPDM E/R from vehicle.

Check resistance between ECM terminals 94 and 86.

Check resistance between IPDM E/R terminals 39 and 40.6 (W) - 14 (R) : Continuity should not exist.
PKIA2077E
6 (W) - Ground : Continuity should not exist.
14 (R) - Ground : Continuity should not exist.
PKIA2079E
Unit TerminalResistance value (Ω)
(Approx.)
ECM 94 - 86
108 - 132
IPDM E/R 39 - 40
LKIA0037E

LAN-110
[CAN]
CAN SYSTEM (TYPE 3)
Revision: August 20072004 QX56
Case 12
Check front air control circuit. Refer to LAN-122, "Front Air Control Circuit Check" .
PKIA8080E
PKIA8167E

CAN SYSTEM (TYPE 3)
LAN-115
[CAN]
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LAN
Revision: August 20072004 QX56
Case 18
Check IPDM E/R ignition relay circuit continuously sticks “ON”. Refer to LAN-124, "IPDM E/R Ignition Relay
Circuit Check" .
Circuit Check Between TCM and Driver Seat Control UnitUKS0019W
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
–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 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.
PKIA8086E
3 (W) - 12 (W) : Continuity should exist.
8 (R) - 11 (R) : Continuity should exist.
PKIA6831E

LAN-116
[CAN]
CAN SYSTEM (TYPE 3)
Revision: August 20072004 QX56
3. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect harness connector E34.
2. Check continuity between harness connector E19 terminals 12
(W), 11 (R) and harness connector E34 terminals 24 (W), 23 (R).
OK or NG
OK >> GO TO 4.
NG >> Repair harness.
4. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect driver seat control unit connector.
2. Check continuity between harness connector B40 terminals 24
(W), 23 (R) and driver seat control unit harness connector P2
terminals 3 (W), 19 (R).
OK or NG
OK >> Connect all the connectors and diagnose again. Refer to
LAN-95, "
Work Flow" .
NG >> Repair harness.
Circuit Check Between Driver Seat Control Unit and Data Link ConnectorUKS0019X
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.12 (W) - 24 (W) : Continuity should exist.
11 (R) - 23 (R) : Continuity should exist.
PKIA6832E
24 (W) - 3 (W) : Continuity should exist.
23 (R) - 19 (R) : Continuity should exist.
PKIA6840E
3 (W) - 51J (W) : Continuity should exist.
19 (R) - 52J (R) : Continuity should exist.
PKIA6841E

CAN SYSTEM (TYPE 3)
LAN-117
[CAN]
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LAN
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-95, "
Work Flow" .
NG >> Repair harness.
Circuit Check Between Data Link Connector and IPDM E/RUKS0019Y
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-95, "
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

LAN-118
[CAN]
CAN SYSTEM (TYPE 3)
Revision: August 20072004 QX56
ECM Circuit CheckUKS0019Z
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 CheckUKS001A0
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

CAN SYSTEM (TYPE 3)
LAN-119
[CAN]
C
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LAN
Revision: August 20072004 QX56
Driver Seat Control Unit Circuit CheckUKS001A1
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 (W) and 19 (R).
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 CheckUKS001A2
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 (W) and 12 (R).
OK or NG
OK >> Replace combination meter.
NG >> Repair harness between combination meter and data
link connector. 3 (W) - 19 (R) : Approx. 54 - 66Ω
PKIA6842E
11 (W) - 12 (R) : Approx. 54 - 66Ω
PKIA6837E

LAN-120
[CAN]
CAN SYSTEM (TYPE 3)
Revision: August 20072004 QX56
Display Control Unit Circuit CheckUKS001A3
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 (W) and 26 (R).
OK or NG
OK >> Replace display control unit.
NG >> Repair harness between display control unit and data
link connector.
BCM Circuit CheckUKS001A4
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 (W) and 40 (R).
OK or NG
OK >> Replace BCM. Refer to BCS-19, "Removal and Installa-
tion of BCM" .
NG >> Repair harness between BCM and data link connector.25 (W) - 26 (R) : Approx. 54 - 66Ω
SKIA6884E
39 (W) - 40 (R) : Approx. 54 - 66Ω
SKIA6869E