Lexus RX300 (MCU15). Service manual - part 374

DI27W–07

Vehicle Brought to Workshop

Customer Problem Analysis

Check and Clear DTC (Pre check)

Items inside

are titles of pages in this manual,

with the page number in the bottom portion. See
the pages for detailed explanations.

Problem Symptom Confirmation

 

Symptom
does not occur

Symptom
occurs

DTC Check

DTC Chart

Malfunction code

Problem Symptoms Table

Identification of Problem

Normal code

Repair

Confirmation Test

End

1

2

3

4

5

6

7

8

9

10

P. DI–727

P. DI–728

P. IN–22

P. DI–756

P. DI–728

P. DI–745

P. DI–752

Terminal of ECU

Symptom Simulation

DI–726

–

DIAGNOSTICS

LEXUS NAVIGATION SYSTEM

LEXUS RX300   (RM785E)

LEXUS NAVIGATION SYSTEM

HOW TO PROCEED WITH TROUBLESHOOTING

HINT:
The ECU of this system is connected to the multiplex communication system. Therefore, before starting trou-
bleshooting, make sure to check that there is no trouble in the multiplex communication system.

DI27X–06

–

DIAGNOSTICS

LEXUS NAVIGATION SYSTEM

DI–727

LEXUS RX300   (RM785E)

CUSTOMER PROBLEM ANALYSIS CHECK

NAVIGATION SYSTEM Check Sheet

Inspector’s name:

Customer’s Name

Date of Vehicle

Registration No.

Registration Year

Frame No.

Odometer Reading

             /               /

km
Mile

Frequency Problem Occurs

                              /                                /

j

 Constant       j Intermittent (      Times a day)

Brought in

j

 Cursor movement is defective.

Date Problem First Occurred

Problem

 Symptom

j

 Cursor does not move.

j

 GPS mark does not appear.

j

 Map is not displayed.

j

 Screen is dark.

j

 Screen is white.

j

 Color is not uniform.

j

 Screen is in disorder.

j

 Can not operate with panel switches.

j

 Can not operate with touch switches.

j

 Others (                    )

j

 Others (                    )

j

 Others (                    )

Navigation
malfunction

Display
malfunction

Control
Switch
malfunction

Navigation ECU

Multi Display

Radio receiver assembly

DTC Check

Parts name

1st time malfunction code.

2nd time malfunction code.

DI7OR–03

I17101

Navigation system normal operation

to 2. SYSTEM CHECK MODE SCREEN

to 4. DISPLAY 
CHECK MODE SCREEN

to 3. NAVIGATION 
CHECK MODE SCREEN

Diagnosis start–up. (refer to next page)

HINT:

When Diagnosis Sys-
tem mode is started,
system check is per-
formed at first and the
check result is dis-
played.

DI–728

–

DIAGNOSTICS

LEXUS NAVIGATION SYSTEM

LEXUS RX300   (RM785E)

PRE–CHECK

1.

DIAGNOSIS SYSTEM MODE

HINT:
Diagnosis System Mode is operated as follows.

I19230

LHD:

RHD:

I17110

Concealed 
touch 
switch

–

DIAGNOSTICS

LEXUS NAVIGATION SYSTEM

DI–729

LEXUS RX300   (RM785E)

(a)

DIAGNOSIS START–UP
To start the diagnosis menu, there are 2 ways: using a
diagnosis check wire and using a switch.

(b)

START–UP BY SWITCH OPERATION
(1)

Vehicle speed is 0 km/h (0 mph).

(2)

Parking brake switch is pressed.

(3)

Press the Display switch to display the Screen Ad-
justment screen.

(4)

Repeatedly touch the upper and lower bottom parts
of the left end of the screen 3 times.

(c)

FINISHING DIAGNOSIS SYSTEM MODE
Turn the ignition switch from ACC to OFF to finish the
mode. If it is started by switch operation.