control INFINITI M35 2007 Factory Service Manual

TROUBLE DIAGNOSIS
LAN-11
[CAN FUNDAMENTAL]
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Revision: 2007 April2007 M35/M45
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 OFF.)

The steering lock does not release (if an error or malfunction occurs while turning
the ignition switch 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/RWhen the ignition switch is ON,

The headlamps (Lo) turn ON.

The cooling fan continues to rotate.

LAN-12
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Self-DiagnosisNKS004HE
DTCSelf-diagnosis item
(CONSULT-II indication)DTC detection condition Inspection/Action
U1000 CAN COMM CIRCUITWhen 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 CIRCUITWhen ECM is not transmitting or receiving CAN
communication signal other than OBD (emis-
sion-related diagnosis) for 2 seconds or more.
U1002 SYSTEM COMMWhen 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
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Revision: 2007 April2007 M35/M45
CAN Diagnostic Support MonitorNKS004HF
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 diagnosisOK Normal at present
NG Control unit error (Except for some control units)
Transmission diagnosisOK Normal at present
UNKWNUnable to transmit signals for 2 seconds or more.
Diagnosis not performed
Control unit name
(Reception diagnosis)OK Normal at present
UNKWNUnable 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 diagnosisOKOK Normal at present and in the past
1 – 39Normal 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)OKOK Normal at present and in the past
1 – 39Normal 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: 2007 April2007 M35/M45
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
ItemResult indi-
catedError counter Description
CAN_COMM
(Initial diagnosis)OK 0 Normal at present
NG 1 – 50Control unit error
(The number indicates how many times diagnosis has been
run.)
CAN_CIRC_1
(Transmission diagnosis)OK 0 Normal at present
UNKWN 1 – 50Unable 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 – 50Unable 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
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Revision: 2007 April2007 M35/M45
TROUBLE DIAGNOSES WORK FLOWPFP:00004
Information Needed for Trouble DiagnosisNKS004HG
CAN communication system performs trouble diagnosis with the following tools.
How to Use CAN Communication Signal ChartNKS004HH
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 sheetFor 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
chartFor 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

TROUBLE DIAGNOSES WORK FLOW
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Revision: 2007 April2007 M35/M45
Trouble Diagnosis ProcedureNKS004HJ
INTERVIEW WITH CUSTOMER
Interview with the customer is important to detect the root cause of CAN communication system errors and to
understand vehicle condition and symptoms for proper trouble diagnosis.
Points in interview

What: Parts name, system name

When: Date, Frequency

Where: Road condition, Place

In what condition: Driving condition/environment

Result: Symptom
NOTE:

Check normal units as well as error symptoms.
–Example: Circuit between ECM and the combination meter is judged normal if the customer indicates
tachometer functions normally.

When a CAN communication system error is present, multiple control units may malfunction or go into fail-
safe mode.

Indication of the combination meter is important to detect the root cause because it is the most obvious to
the customer, and it performs CAN communication with many units.
SKIB8717E

TROUBLE DIAGNOSES WORK FLOW
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Revision: 2007 April2007 M35/M45
DETECT THE ROOT CAUSE
Identify the root cause using the created diagnosis sheet.
Identifying the root cause

Draw a line on the diagnosis sheet to indicate the possible cause. Narrow the search.
NOTE:

Color-code when drawing lines.

Do not draw a line onto a existing line.

Drawing a line is not necessary if the circuit is shorted. Refer to LAN-32, "Present Error — Short Circuit —
" , LAN-39, "Past Error — Short Circuit —" .
Refer to the following for details of the trouble diagnosis procedure.

LAN-26, "Present Error — Open Circuit —"

LAN-32, "Present Error — Short Circuit —"

LAN-33, "Past Error — Open Circuit —"

LAN-39, "Past Error — Short Circuit —"
NOTE:
When the root cause appears to be a branch line or short circuit, be sure to check the control unit as well as
the communication line.

LAN-26
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
Revision: 2007 April2007 M35/M45
Present Error — Open Circuit —
Identify the error circuit using information from the “SELECT SYSTEM” and “CAN DIAG SUPPORT MNTR”
screens.
1. SELECT SYSTEM: Check the items indicated in “SELECT SYSTEM”. Draw a line on the diagnosis sheet
to indicate the error circuit.
NOTE:
CAN communication line has no error if units other than Diag on CAN units are not indicated. An error
may be on the power supply of the control unit, DDL1 line or DDL2 line.
a. “TRANSMISSION” which is Diag on CAN unit, is not indicated on “SELECT SYSTEM” screen. This indi-
cates that DLC is not receiving a signal from TCM. Draw a line to indicate an error between DLC and
TCM (line 1-a in the figure).
NOTE:

Diag on CAN units are not indicated on the “SELECT SYSTEM” screen when the CAN line between
Diag on CAN unit and the data link connector is open.

For a description of Diag on CAN, refer to LAN-6, "Diag on CAN" .
SKIB8892E

TROUBLE DIAGNOSES WORK FLOW
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Revision: 2007 April2007 M35/M45
2. CAN DIAG SUPPORT MNTR: Check each item on “CAN DIAG SUPPORT MNTR”. Draw a line on the
diagnosis sheet to indicate the error circuit.
a. Reception item of “ENGINE”: On “TCM”, “UNKWN” is indicated. This means ECM cannot receive the sig-
nal from TCM. Draw a line to indicate an error between ECM and TCM (line 2-a in the figure).
NOTE:
If “UNKWN” is indicated on “TRANSMIT DIAG”, then the control unit cannot transmit CAN communication
signal to each unit. Draw a line between the control unit and the splice.
b. Reception item of “ADAPTIVE LIGHT”: On “TCM”, “UNKWN” is indicated. This means AFS cannot
receive the signal from TCM. Draw a line to indicate an error between AFS and TCM (line 2-b in the fig-
ure).
c. Reception item of “MULTI AV”: “UNKWN” is not indicated. This indicates normal communication between
AV and its receiving units. Do not draw any line.
SKIB8725E

TROUBLE DIAGNOSES WORK FLOW
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Revision: 2007 April2007 M35/M45
Past Error — Open Circuit —
Review CAN communication signal chart based on information received from the interview with the customer
and on past error information from SELF-DIAG RESULTS and CAN DIAG SUPPORT MNTR.
1. SELF-DIAG RESULTS: Inspect the control units indicating “U1000” or “U1001” on SELF-DIAG RESULTS.
SKIB8731E