Lexus RX300 (MCU15). Service manual - part 375

I15446

to 1. Diagnosis 
MENU screen

DTC memory and history clear

DTC memory clear

Recheck

DTC clear

When there are individual DTC data.

Yes

No

DI–730

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DIAGNOSTICS

LEXUS NAVIGATION SYSTEM

LEXUS RX300   (RM785E)

2.

SERVICE CHECK MODE

HINT:
Service Check Mode is operated as follows.

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Recheck

Memory clear switch

DTC clear switch

Check result

Components name

Diagnosis MENU 
screen switch

–

DIAGNOSTICS

LEXUS NAVIGATION SYSTEM

DI–731

LEXUS RX300   (RM785E)

(a)

SERVICE CHECK SCREEN

(1)

By performing system check and collecting data of diagnosis memory, this mode checks the cur-
rent and past condition of the vehicle.

(2)

List of all components name or physical addresses. 
It displays only the components that have been connected at least once.

(3)

The check result is displayed for all components.

(4)

The check result is displayed by 6 abbreviations: ”OK”, ”EXCH”, ”CHEK”, ”NCON”, ”NRES” and
”Old”. (”EXCH”, ”CHEK” and ”Old” have a function as switches.)

(5)

Based on all information obtained from ”System Check Request”, ”Diagnosis Memory Request”
and ”Current Diagnosis Result” command, the following results are displayed:
OK: No error is identified.
EXCH: One or more error codes requesting for exchange are detected in any check result.
CHEK: Except the conditions for ”EXCH”, one or more error codes requesting for check are de-
tected in any check result.

(6)

The other check results are as follows:
NCON: No response to ”Diagnosis ON Instruction” command and it is not connected when the
system is started.
Old: One or more error codes are detected when responding to ”Diagnosis ON Instruction” com-
mand because of the old version .
NRES: No response to all commands of ”System Check Request”, ”Diagnosis Memory Request”
and ”Current Diagnosis Result”. Or no error is detected by any one of ”System Check Request”
or ”Diagnosis Memory Request” when no response to the other command.

(7)

”EXCH”, ”CHEK” and ”Old” are functioned as switches any by pressing these, LAN Check Mode
and Unit Check Mode are activated.

(8)

Memory Clear Switch
Pressing this switch for 3 sec. deletes all information about master component registration and
diagnosis memory of all components.

(9)

DTC Clear Switch
Pressing this switch for 3 sec. deletes diagnosis memory of all components.

(10) Recheck Switch

Pressing this switch rechecks the system.

(11) Menu Switch

Pressing this switch activated the Diagnosis Menu Screen.

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Service check mode
screen switch

Unit check mode
screen switch

DTC clear switch

Number of occurrence

Connection confirmation number

Related components parts

DTC

Segment

Components name

DI–732

–

DIAGNOSTICS

LEXUS NAVIGATION SYSTEM

LEXUS RX300   (RM785E)

(b)

LAN CHECK MODE SCREEN

(1)

As a detailed screen in the System Check Mode, LAN Check Mode is displayed.

(2)

Communication codes (logical address ”01”) are extracted from the diagnosis data obtained by
”Diagnosis Memory Request” and displayed.

(3)

Component Name
Names of the components to be checked are displayed.

(4)

Segment
Logical address codes corresponding to DTC are displayed.

(5)

DTC
DTC displayed.

(6)

Related components address
Physical address codes corresponding to DTC are displayed.

(7)

Connection Confirmation Number
Connection confirmation numbers corresponding to DTC is displayed.

(8)

Number of Occurrence
The number of occurrence of the same DTC is displayed.

(9)

DTC Clear Switch
Pressing this switch for 3 sec. deletes DTC memory of the selected diagnosis component. When
returning to the System Check Mode, the check result is shown as a blank.

(10) Unit Check Mode Screen Switch

Pressing this switch activates the Unit Check Mode screen.

(11) System Check Mode Screen Switch

Pressing this switch activates the System Check Mode screen.

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System check mode
screen switch

LAN check mode
screen switch

DTC

Segment

Components name

DTC clear switch

Segment

DTC

Year/Month/Day

Hour/Minute/Second

–

DIAGNOSTICS

LEXUS NAVIGATION SYSTEM

DI–733

LEXUS RX300   (RM785E)

(c)

UNIT CHECK MODE SCREEN

(1)

As a detailed screen in the System Check Mode, the Unit Check Mode is displayed.

(2)

Up to 6 error codes detected by ”The DTC obtained during the system check (including when
starting the diagnosis mode)” can be displayed as ”Current”.

(3)

Up to 6 error codes detected by ”DTC stored in the past” can be displayed as ”Memory”.

(4)

Component Name
Names of the components are displayed.

(5)

Segment
Logical address numbers corresponding to DTC are displayed.

(6)

DTC
DTC is displayed.

(7)

Year/Month/Day/Hour/Minute/Second
The date and time stamped at the time of code occurrence is displayed in the order of year–
month–day–hour–minute–second.  (Year is shown in 2–digit number.) If the date and time data
is invalid, it is displayed as a blank.

HINT:
Time data is obtained after turning the ignition from ACC to ON. Until the valid time data is obtained, the data
shown in the display shall be considered as invalid.
If stored before a valid time data is obtained, the data shall not be displayed.

(8)

DTC Clear Switch
Pressing this switch for 3 sec. deletes all diagnosis memory of the component. When returning
to the System Check Mode, the check result is displayed as a blank.

(9)

Lan Check Mode Screen Switch
Pressing this switch activates the LAN Check Mode screen.

(10) System Check Mode Screen .Switch

Pressing this switch activates the System Check Mode screen.