Nissan Titan A60. Manual - part 679

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< SYSTEM DESCRIPTION >

[CAN FUNDAMENTAL]

TROUBLE DIAGNOSIS

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)

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DIAGNOSIS AND REPAIR WORKFLOW

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< BASIC INSPECTION >

[CAN FUNDAMENTAL]

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BASIC INSPECTION

DIAGNOSIS AND REPAIR WORKFLOW

Information Needed for Trouble Diagnosis

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CAN communication system performs trouble diagnosis with the following tools.

How to Use CAN Communication Signal Chart

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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 copying on-board diagnosis data.

Diagnosis sheet

For detecting the root cause. (Diagnosis sheet includes system diagram for every CAN system type)

ECU list
(On the “CAN DIAG SUPPORT 
MNTR”)

For checking the condition of control units and the status of CAN communication.

SELF-DIAG RESULTS
(CONSULT-III)

CAN DIAG SUPPORT MNTR
(CONSULT-III)

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

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< BASIC INSPECTION >

[CAN FUNDAMENTAL]

DIAGNOSIS AND REPAIR WORKFLOW

Trouble Diagnosis Flow Chart

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Trouble Diagnosis Procedure

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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

PKID1210E

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DIAGNOSIS AND REPAIR WORKFLOW

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• 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.

INSPECTION OF VEHICLE CONDITION

• Check whether or not “U1000” or “U1001” is indicated on “SELF-DIAG RESULTS” by CONSULT-III.

NOTE:

Root cause cannot be detected using the procedure in this section if “U1000” or “U1001” is not indicated.

• Check whether the symptom is reproduced or not.

NOTE:

• Do not turn the ignition switch OFF or disconnect the battery cable while reproducing the error. The error

may temporarily correct itself, making it difficult to determine the root cause.

• The procedures for present errors differ from the procedures for past errors. Refer to “DETECT THE

ROOT CAUSE”.

CHECK OF CAN SYSTEM TYPE (HOW TO USE CAN SYSTEM TYPE SPECIFICATION CHART)

Determine CAN system type based on vehicle equipment. Then choose the correct diagnosis sheet.

NOTE:

There are two styles for CAN system type specification charts. Depending on the number of available system

types, either style A or style B may be used.

CAN System Type Specification Chart (Style A)

NOTE:

SKIB8717E