control unit INFINITI M35 2007 Factory Service Manual

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
LAN-15
[CAN FUNDAMENTAL]
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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
LAN-17
[CAN FUNDAMENTAL]
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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
LAN-25
[CAN FUNDAMENTAL]
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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
LAN-27
[CAN FUNDAMENTAL]
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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
LAN-33
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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

LAN-38
[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
Revision: 2007 April2007 M35/M45
6. The circuit which has the most amount of lines are the possible cause. Error is detected from ABS actua-
tor and electric unit (control unit) branch line (shaded in the figure).
NOTE:
For abbreviations, refer to LAN-41, "
Abbreviation List" .
7. Perform the inspection procedure for the possible cause. Refer to LAN-82, "
Malfunction Area Chart" .
SKIB8896E

LAN-40
[CAN]
INDEX FOR DTC
Revision: 2007 April2007 M35/M45
[CAN]INDEX FOR DTCPFP:00004
DTC No. IndexNKS004FM
DTCSelf-diagnosis item
(CONSULT-II indication)DTC detection condition Inspection
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-41, "
HOW
TO USE THIS SEC-
TION" . 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”.

HOW TO USE THIS SECTION
LAN-41
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Revision: 2007 April2007 M35/M45
HOW TO USE THIS SECTIONPFP:00008
CautionNKS004FN

This section describes information specific to a vehicle, sheets for trouble diagnosis, and inspection pro-
cedures.

For trouble diagnosis procedure, refer to LAN-17, "Trouble Diagnosis Procedure" .
Abbreviation ListNKS004FO
Abbreviations in CAN communication signal chart and the diagnosis sheet are as per the following list.
Abbreviation Unit nameSELECT SYSTEM
(CONSULT-II)CAN DIAG SUPPORT MNTR
(CONSULT-II)
4WD AWD control unit ALL MODE AWD/4WD AWD/4WD
ABS ABS actuator and electric unit (control unit) ABS VDC/TCS/ABS
ADP Driver seat control unit AUTO DRIVE POS. –
AFS AFS control unit ADAPTIVE LIGHT AFS
AVNAVI control unit
MULTI AVMULTI AV
DISPLAY
AV control unitMULTI AV
DISPLAY
BCM BCM BCM BCM/SEC
DLC Data link connector – –
ECM ECM ENGINE ECM
ICC ICC sensor integrated unit ICCICC
ICC/e4WD
I-KEY Intelligent Key unit INTELLIGENT KEY I-KEY
IPDM-E IPDM E/R IPDM E/R IPDM E/R
M&A Unified meter and A/C amp. METER A/C AMP METER/M&A
PSB Pre-crash seat belt control unit PRECRASH SEATBELT –
RAS RAS control unit RAS/HICAS RAS C/U
STRG Steering angle sensor – STRG
TCM TCM A/T TCM
TPMS Low tire pressure warning control unit AIR PRESSURE MONITOR TIRE-P
LANE LDW camera unit LDW –