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 “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.

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.

TROUBLE DIAGNOSIS LAN-9
[CAN FUNDAMENTAL]
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Revision: 2006 July 2007 FX35/FX45
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.

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.

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.

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”.

TROUBLE DIAGNOSIS LAN-13
[CAN FUNDAMENTAL]
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Revision: 2006 July 2007 FX35/FX45
CAN Diagnostic Support MonitorNKS004MF
CONSULT-II and CAN diagnostic support monitor (on-board diagnosis function) are used for detecting root
cause.
MONITOR ITEM (CONSULT-II)
Example: CAN DIAG SUPPORT MNTR indication
Without PAST
With PAST
SKIB8742E
Item PRSNT Description
Initial diagnosis OK Normal at present
NG Control unit error (Except for some control units)
Transmission diagnosis OK Normal at present
UNKWN Unable to transmit signals for 2 seconds or more.
Diagnosis not performed
Control unit name
(Reception diagnosis) OK Normal at present
UNKWN Unable to receive signals for 2 seconds or more.
Diagnosis not performed
No control unit for receiving signals. (No applicable optional parts)
Item PRSNT PAST Description
Transmission diagnosis OK OK Normal at present and in the past
1 – 39 Normal at present, but unable to transmit signals for 2 seconds or more
in the past. (The number indicates the number of ignition switch cycles
from OFF to ON.)
UNKWN 0 Unable to transmit signals for 2 seconds or more at present.
Control unit name
(Reception diagnosis) OK
OK Normal at present and in the past
1 – 39 Normal at present, but unable to receive signals for 2 seconds or more
in the past. (The number indicates the number of ignition switch cycles
from OFF to ON.)
UNKWN 0 Unable to receive signals for 2 seconds or more at present
–– Diagnosis not performed.
No control unit for receiving signals. (No applicable optional parts)

LAN-14
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
MONITOR ITEM (ON-BOARD DIAGNOSIS)
NOTE:
For some models, CAN communication diagnosis result is received from the vehicle monitor. (CONSULT-II is
not available.)
Example: Vehicle Display
Item Result indi-
cated Error counter Description
CAN_COMM
(Initial diagnosis) OK 0 Normal at present
NG 1 – 50 Control unit error
(The number indicates how many times diagnosis has been
run.)
CAN_CIRC_1
(Transmission diagnosis) OK 0 Normal at present
UNKWN 1 – 50 Unable to transmit for 2 seconds or more at present.
(The number indicates how many times diagnosis has been
run.)
CAN_CIRC_2 – 9
(Reception diagnosis of each unit) OK 0 Normal at present
UNKWN 1 – 50 Unable to transmit for 2 seconds or more at present.
(The number indicates how many times diagnosis has been
run.)
Diagnosis not performed.
No control unit for receiving signals. (No applicable optional
parts)

TROUBLE DIAGNOSES WORK FLOW LAN-15
[CAN FUNDAMENTAL]
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Revision: 2006 July 2007 FX35/FX45
TROUBLE DIAGNOSES WORK FLOWPFP:00004
Information Needed for Trouble DiagnosisNKS004MG
CAN communication system performs trouble diagnosis with the following tools.
How to Use CAN Communication Signal ChartNKS004MH
The CAN communication signal chart lists the signals needed for trouble diagnosis. It is useful for detecting
the root cause by finding a signal related to the symptom, and by checking transmission and reception unit.
Tool Usage
Interview sheet For filling in vehicle information and interview with customer.
Data sheet For attaching CONSULT-II data or on-board diagnosis data.
Diagnosis sheet For detecting the root cause. (Diagnosis sheet includes system diagram for every CAN system
type)
SELECT SYSTEM
(CONSULT-II)
For checking the condition of control units and the status of CAN communication.
SELF-DIAG RESULTS
(CONSULT-II)
CAN DIAG SUPPORT MNTR
(CONSULT-II)
CAN communication signal
chart For converting information received from a customer into CAN communication signal transmission
and reception. This information can be used to judge whether a circuit between control units is nor-
mal or abnormal.
Abbreviation list For checking abbreviations in CAN communication signal chart and diagnosis sheet.
SKIB8715E

LAN-16
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
Revision: 2006 July 2007 FX35/FX45
Trouble Diagnosis Flow ChartNKS004MI
SKIB8716E