Lexus RX300 (MCU15). Manual — part 310

DI08F–18

Customer Problem Analysis

Check and Clear DTC (Precheck)

Vehicle Brought to Workshop

Problem Symptom Confirmation

Symptom Simulation

Symptom does not occur

DTC Check

Normal code

DTC Chart

Problem Symptom Table

Circuit Inspection

Input Signal Check

Parts Inspection

Identification of Problem

Repair

Confirmation Test

End

Items inside

are titles of pages in this

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

1

2

3

4

5

6

7

8

9

10

Step 2, 5: Diagnostic steps permitting the use

of the hand–held tester or break–
out–box.

P. DI–473

P. DI–474

P. DI–474

P. DI–479

P. IN–22

P. DI–483

P. DI–484 – DI–496

OK

NG

Symptom occurs

Malfunction code

DI–472

–

DIAGNOSTICS

CRUISE CONTROL SYSTEM

LEXUS RX300 (RM785E)

CRUISE CONTROL SYSTEM

HOW TO PROCEED WITH TROUBLESHOOTING

Troubleshoot in accordance with the procedure on the following page.

DI08G–07

CRUISE CONTROL SYSTEM Check Sheet

Inspector’s name:

Customer’s Name

Date Vehicle

Registration No.

Registration Year

Frame No.

Odometer Reading

/ /

km
Mile

Condition of
Problem Occurrence

Date of Problem

How Often does

Occurrence

Problem Occurs

Vehicle Speed when
Problem Occurred

/ /

"" Continuous "" Intermittent ( Times a day)

km
Mile

Brought in

"" Auto cancel
occurs

D

Driving condition

j

City driving j Freeway j Up hill j Down hill

D

After cancel occurred, did the driver activate cruise control
again?

j

Yes j No

j

Cancel does not

occur

j

With brake ON

j

Except D position shift j At 40 km/h (25 mph) or less

j

When control SW turns to CANCEL position

j

Cruise control

malfunction

j

Slip to acceleration side

j

Slip to deceleration side

j

Hunting occurs

j

O/D cut off does not occur

j

O/D does not return

j

Switch

malfunction

j

SET j ACCEL j COAST j RESUME j CANCEL

j

Cruise MAIN

indicator light

j

Remains ON j Does not light up j Blinking

Symptoms

DTC Check

1st Time

2nd Time

j

Normal Code j Malfunction Code (Code )

j

Normal Code j Malfunction Code (Code )

–

DIAGNOSTICS

CRUISE CONTROL SYSTEM

DI–473

LEXUS RX300 (RM785E)

CUSTOMER PROBLEM ANALYSIS CHECK

I07348

DI1KS–11

BE4034

Indicator Light

1.5 sec.

0.5 sec.

ON

OFF

N09214

Tc

CG

DI–474

–

DIAGNOSTICS

CRUISE CONTROL SYSTEM

LEXUS RX300 (RM785E)

PRE–CHECK

1.

DIAGNOSIS SYSTEM

(a)

Check the indicator.
(1)

Turn the ignition switch ON.

(2)

Check that the CRUISE MAIN indicator light comes
ON when the cruise control main switch is turned
ON, and that the indicator light goes OFF when the
main switch is turned OFF.

HINT:
If the indicator check result is not normal, proceed to trouble-
shooting (See page BE–62) for the combination meter section.

(b)

Check the DTC.

HINT:
If a malfunction occurs in the No. 1 vehicle speed sensor or ac-
tuator, etc. during cruise control driving, the ECU actuates
AUTO CANCEL of the cruise control and turns on and off the
CRUISE MAIN indicator light to inform the driver of a malfunc-
tion. At the same time, the malfunction is stored in memory as
a DTC.

(c)

Output of DTC using diagnosis check wire.
(1)

Turn the ignition switch ON.

(2)

Using SST, connect terminals Tc and CG

of DLC3.

SST

09843–18020

(3)

Read the DTC on the CRUISE MAIN indicator light.

BE4032

BE4033

I00021

Normal Code

0.25 sec.

0.25 sec.

ON

OFF

ON

OFF

4 sec.

1.5 sec.

0.5 sec.

2.5 sec.

0.5 sec.

1.5 sec.

Malfunction codes 11 and 21

Code 11

Code 21

D09456

DLC3

Hand–held Tester

I14404

(b)

CG

(d) 5 times
within 3 seconds

Tc

(c)

–

DIAGNOSTICS

CRUISE CONTROL SYSTEM

DI–475

LEXUS RX300 (RM785E)

HINT:
If the DTC is not output, inspect the diagnosis circuit (See page
DI–514).
As an example, the blinking patterns for codes; normal, 11 and
21 are shown in the illustration.

2.

USING HAND–HELD TESTER

(a)

Hook up the hand–held tester to the DLC3.

(b)

Monitor the ECU data by following the prompts on the tes-
ter screen.

HINT:
Hand–held tester has a ”Snapshot” function which records the
monitored data.
Please refer to the hand–held tester operator’s manual for fur-
ther details.

3.

DTC CLEARANCE (ERASE MODE)

HINT:
During in the erase mode, diag detection does not work.
(a)

Drive at about 15 km/h or below.

(b)

Using SST, connect terminals Tc and E1 of DLC3.
SST

09843–18020

(c)

Pull the cruise control switch to CANCEL.

(d)

On the above metioned condition, turn on the cruise con-
trol main switch 5 times within 3 seconds.