Lexus RX300 (MCU15). Service manual - part 322

DI1AJ–23

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 Simulation

 

Symptom
does not occur

Symptom
occurs

DTC Check

Circuit Inspection and Part Inspection

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

Step 2, 5 :

 

P. DI–521

P. DI–522

P. IN–22

P. DI–528

P. DI–522

P. DI–525

P. DI–529 – DI–535

Diagnostic steps permitting the use of the
hand–held tester or break–out–box.

DI–520

–

DIAGNOSTICS

ENGINE IMMOBILISER SYSTEM

LEXUS RX300   (RM785E)

ENGINE IMMOBILISER SYSTEM

HOW TO PROCEED WITH TROUBLESHOOTING

Troubleshooting  in accordance with the procedure on the following pages.

DI1AK–01

ENGINE IMMOBLISER Check Sheet

Inspector’s

Name

:

Customer’s Name

Date Vehicle
Brought In

Registration Year

Registration No.

Frame No.

Odometer Reading

/              /

/              /

Date Problem First Occurred

Frequency Problem Occurs

/                            /

Continuous

Intermittent (       times a day)

DTC Check

1st Time

2nd Time

Normal Code

Malfunction Code (Code         )

Normal Code

Malfunction Code (Code         )

Symptoms

km

miles

Engine does not start

Check Item

Malfunction
Indicator Lamp

Normal

Remains ON

Does not Light Up

Immobiliser is not set.
(Engine starts with key codes other than the registered key code,)

–

DIAGNOSTICS

ENGINE IMMOBILISER SYSTEM

DI–521

LEXUS RX300   (RM785E)

CUSTOMER PROBLEM ANALYSIS CHECK

D09456

Hand–held Tester

DLC3

DI1AL–22

N09214

DI–522

–

DIAGNOSTICS

ENGINE IMMOBILISER SYSTEM

LEXUS RX300   (RM785E)

PRE–CHECK

1.

DIAGNOSIS SYSTEM

(a)

Description
Engine & ECT ECU controls the function of immobiliser
on this vehicle.
Data of the immobiliser or DTC can be read form DLC3 of
the vehicle. When a trouble occurs on immobiliser, check
engine warning light does not light on but DTC inspection
is performed.
Therefore when there seems to be a trouble on immobilis-
er, use hand–held tester or SST to check and trouble-
shoot it.

(b)

Inspect the DLC3.
The vehicle’s engine & ECT ECU uses ISO 9141–2 for
communication.
The terminal arrangement of DLC3 complies with
SAEJ1962 and matches the ISO 9141–2 format.

Tester connection

condition

Specified condition

7 (Bus ę Line) – 5 (Signal ground)

During communication

Pulse generation

4 (chassis Ground) – Body

Always

1 Ω or less

5 (Signal Ground) – Body

Always

1 Ω or less

16  (B+) – Body

Always

9 – 14 V

HINT:
If your display shows ”UNABLE TO CONNECT TO VEHICLE”
when you have connected the cable of hand–held tester to
DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.

S

If communication is normal when the tool is connected to
another vehicle, inspect DLC3 on the original vehicle.

S

If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in the
tool itself, so consult the Service Department listed in the
tool’s instruction manual.

N09214

BR3904

Normal code

0.25 Sec.

0.25 Sec.

–

DIAGNOSTICS

ENGINE IMMOBILISER SYSTEM

DI–523

LEXUS RX300   (RM785E)

2.

INSPECT DIAGNOSIS

(a)

Check the DTC (Using hand–held tester)
(1)

Prepare the hand–held tester.

(2)

Connect the hand–held tester to DLC3 under the
instrument panel lower pad.

(3)

Turn the ignition switch ON and turn the hand–held
tester switch ON.

(4)

Use the hand–held tester to check the DTCs and
freeze frame data; note them down. (For operating
instructions, see the OBD ll scan tool’s instruction
book.)

(5)

See page DI–525 to confirm the details of the 
DTCs.

(b)

Check the DTC (Using diagnosis check wire)
(1)

Turn ignition switch ON.

(2)

Using SST, connect between terminals 13 (TC) and
4 (CG) of DLC 1.

SST

09843–18040

(3)

Read the diagnostic trouble code from check en-
gine warning light.

HINT:

S

If a diagnostic trouble code is not output, check the Tc ter-
minal circuit.

S

Engine & ECT ECU controls the immobiliser function on
this vehicle, DTC is out put with engine data.

S

As an example, the blinking patterns for codes; normal,
12 and 99 are shown in the illustration.