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SYSTEM DESCRIPTION LAN-5
[CAN FUNDAMENTAL]
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CAN COMMUNICATION CONTROL CIRCUIT
*: These are the only control units wired with both ends of CAN communication system.
SKIB8713E
Component System description
CAN controller It controls CAN communication signal transmission and reception, error detection, etc.
Transceiver IC It converts digital signal into CAN communication signal, and CAN communication signal into digi-
tal signal.
Noise filter It eliminates noise of CAN communication signal.
Termination circuit
*
(Resistance of approx. 120 Ω) It produces potential difference.
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LAN-6
[CAN FUNDAMENTAL]
SYSTEM DESCRIPTION
Revision: 2006 July 2007 FX35/FX45
Diag on CANNKS004MB
DESCRIPTION
“Diag on CAN” is a diagnosis using CAN communication instead of previous DDL1 and DDL2 communication
line, between control unit and diagnosis unit.
SYSTEM DIAGRAM
SKIB8714E
Name Harness Description
DDL1 Tx
Rx It is used for trouble diagnosis. (CAN-H and CAN-L are used for controlling)
DDL2 K-LINE It is used for trouble diagnosis. (CAN-H and CAN-L are used for controlling)
Diag on CAN CAN-H
CAN-L It is used for trouble diagnosis and control.
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![INFINITI FX35 2007 Service Manual TROUBLE DIAGNOSIS LAN-7
[CAN FUNDAMENTAL]
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Revision: 2006 July 2007 FX35/FX45
TROUBLE DIAGNOSISPFP:00004
Condition of Error DetectionNKS004MC
“U1000” or “ INFINITI FX35 2007 Service Manual TROUBLE DIAGNOSIS LAN-7
[CAN FUNDAMENTAL]
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TROUBLE DIAGNOSISPFP:00004
Condition of Error DetectionNKS004MC
“U1000” or “](/manual-img/42/57018/w960_57018-3370.png)
TROUBLE DIAGNOSIS LAN-7
[CAN FUNDAMENTAL]
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TROUBLE DIAGNOSISPFP:00004
Condition of Error DetectionNKS004MC
“U1000” or “U1001” is indicated on SELF-DIAG RESULTS on CONSULT-II if CAN communication signal is not
transmitted or received between units for 2 seconds or more.
CAN COMMUNICATION SYSTEM ERROR
CAN communication line open (CAN-H, CAN-L, or both)
CAN communication line short (ground, between CAN communication lines, other harnesses)
Error of CAN communication control circuit of the unit connected to CAN communication line
WHEN INDICATED “U1000” OR “U1001” IS INDICATED EVEN THOUGH CAN COMMUNICA-
TION SYSTEM IS NORMAL
CONSULT-II CONVERTER not connected: Error may be detected by the self-diagnosis when not using
CONSULT-II CONVERTER (Depending on the control unit which carries out CAN communication).
Removal/installation of parts: Error may be detected when removing and installing CAN communication
unit and related parts while turning the ignition switch ON. (A DTC except for CAN communication may be
detected.)
Fuse blown out (removed): CAN communication of the unit may cease.
Voltage drop: Error may be detected if voltage drops due to discharged battery when turning the ignition
switch ON (Depending on the control unit which carries out CAN communication).
Error may be detected if the power supply circuit of the control unit, which carries out CAN communica-
tion, malfunctions (Depending on the control unit which carries out CAN communication).
Error may be detected if reprogramming is not completed normally.
NOTE:
CAN communication system is normal if “U1000” or “U1001” is indicated on SELF-DIAG RESULTS of CON-
SULT-II under the above conditions. Erase the memory of the self-diagnosis of each unit.
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![INFINITI FX35 2007 Service Manual LAN-8
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Symptom When Error Occurs in CAN Communication SystemNKS004MD
In CAN communication system, multiple units mutually transmit INFINITI FX35 2007 Service Manual LAN-8
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Symptom When Error Occurs in CAN Communication SystemNKS004MD
In CAN communication system, multiple units mutually transmit](/manual-img/42/57018/w960_57018-3371.png)
LAN-8
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Symptom When Error Occurs in CAN Communication SystemNKS004MD
In CAN communication system, multiple units mutually transmit and receive signals. Each unit cannot transmit
and receive signals if any error occurs on CAN communication line. Under this condition, multiple control units
related to the root cause malfunction or go into fail-safe mode.
ERROR EXAMPLE
NOTE:
Each vehicle differs in symptom of each unit under fail-safe mode and CAN communication line wiring.
Refer to LAN-41, "Abbreviation List" for the unit abbreviation.
Example: TCM branch line open circuit
SKIB8738E
Unit name Symptom
ECM Engine torque limiting is affected, and shift harshness increases.
BCM Reverse warning chime does not sound.
EPS control unit Normal operation.
Combination meter
Shift position indicator and OD OFF indicator turn OFF.
Warning lamps turn ON.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R Normal operation.
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![INFINITI FX35 2007 Service Manual TROUBLE DIAGNOSIS LAN-9
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Revision: 2006 July 2007 FX35/FX45
Example: Data link connector branch line open circuit
NOTE:
When data link connec INFINITI FX35 2007 Service Manual TROUBLE DIAGNOSIS LAN-9
[CAN FUNDAMENTAL]
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Example: Data link connector branch line open circuit
NOTE:
When data link connec](/manual-img/42/57018/w960_57018-3372.png)
TROUBLE DIAGNOSIS LAN-9
[CAN FUNDAMENTAL]
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Example: Data link connector branch line open circuit
NOTE:
When data link connector branch line is open, transmission and reception of CAN communication signals
is not affected. Therefore, no symptoms occur. However, be sure to repair malfunctioning circuit.
When data link connector branch line is open, the screen-display of the CONSULT-II “SELECT SYSTEM”
screen may be the same as when the CAN communication line has short-circuit. However, symptoms dif-
fer depending on the case. See below chart for the differences.
SKIB8739E
Unit name Symptom
ECM
Normal operation.
BCM
EPS control unit
Combination meter
ABS actuator and electric unit (control unit)
TCM
IPDM E/R
SELECT SYSTEM (CONSULT-II) Difference of symptom
Data link connector branch line open cir-
cuit All Diag on CAN units are not
indicated. Normal operation.
CAN-H, CAN-L harness short-circuit Most the units which are connected to the CAN com-
munication system enter fail-safe mode or are deac-
tivated.
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LAN-10
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Example: Main Line Between Data Link Connector and ABS Actuator and Electric Unit (Con-
trol Unit) Open Circuit
SKIB8740E
Unit name Symptom
ECM Engine torque limiting is affected, and shift harshness increases.
BCM
Reverse warning chime does not sound.
The front wiper moves under continuous operation mode even though the front
wiper switch being in the intermittent position.
EPS control unit The steering effort increases.
Combination meter
The shift position indicator and OD OFF indicator turn OFF.
The speedometer is inoperative.
The odo/trip meter stops.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R When the ignition switch is ON,
The headlamps (Lo) turn ON.
The cooling fan continues to rotate.
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Revision: 2006 July 2007 FX35/FX45
Example: CAN-H, CAN-L Harness Short Circuit
SKIB8741E
Unit name Symptom
ECM
Eng INFINITI FX35 2007 Service Manual TROUBLE DIAGNOSIS LAN-11
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Example: CAN-H, CAN-L Harness Short Circuit
SKIB8741E
Unit name Symptom
ECM
Eng](/manual-img/42/57018/w960_57018-3374.png)
TROUBLE DIAGNOSIS LAN-11
[CAN FUNDAMENTAL]
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Revision: 2006 July 2007 FX35/FX45
Example: CAN-H, CAN-L Harness Short Circuit
SKIB8741E
Unit name Symptom
ECM
Engine torque limiting is affected, and shift harshness increases.
Engine speed drops.
BCM
Reverse warning chime does not sound.
The front wiper moves under continuous operation mode even though the front
wiper switch being in the intermittent position.
The room lamp does not turn ON.
The engine does not start (if an error or malfunction occurs while turning the igni-
tion switch is OFF.)
The steering lock does not release (if an error or malfunction occurs while turning
the ignition switch is OFF.)
EPS control unit The steering effort increases.
Combination meter
The tachometer and the speedometer do not move.
Warning lamps turn ON.
Indicator lamps do not turn ON.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R When the ignition switch is ON,
The headlamps (Lo) turn ON.
The cooling fan continues to rotate.
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![INFINITI FX35 2007 Service Manual LAN-12
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Self-DiagnosisNKS004ME
DTC Self-diagnosis item
(CONSULT-II indication) DTC detection condition Inspection/Action
U1000 INFINITI FX35 2007 Service Manual LAN-12
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Self-DiagnosisNKS004ME
DTC Self-diagnosis item
(CONSULT-II indication) DTC detection condition Inspection/Action
U1000](/manual-img/42/57018/w960_57018-3375.png)
LAN-12
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Self-DiagnosisNKS004ME
DTC Self-diagnosis item
(CONSULT-II indication) DTC detection condition Inspection/Action
U1000 CAN COMM CIRCUIT When ECM is not transmitting or receiving CAN
communication signal of OBD (emission-related
diagnosis) for 2 seconds or more.
Refer to LAN-15,
"TROUBLE DIAG-
NOSES WORK FLOW" .
When a control unit (except for ECM) is not
transmitting or receiving CAN communication
signal for 2 seconds or more.
U1001 CAN COMM CIRCUIT When ECM is not transmitting or receiving CAN
communication signal other than OBD (emis-
sion-related diagnosis) for 2 seconds or more.
U1002 SYSTEM COMM When a control unit is not transmitting or receiv-
ing CAN communication signal for 2 seconds or
less. Start the inspection.
Refer to the applicable
section of the indicated
control unit.
U1010 CONTROL UNIT [CAN] When an error is detected during the initial diag-
nosis for CAN controller of each control unit. Replace the control unit
indicating “U1010”.