Lexus ES300 (1997 year). Manual - part 417

Diagnostic mode operation confirmation:
Check the buzzer output soon after the input operation
of self diagnostic mode.

Ignition Switch OFF

0.13 sec.

0.5 sec.

OFF

ON

Buzzer

<Reference>



 Buzzer volume should be maximum despite the con-

troller.

Is the method to input the diagnostic mode
correct?

Is the function of operation confirmation
buzzer normal?

Buzzer faulty

No

No

Yes

Confirmation of diagnostic mode:
Check buzzer output when pressing on each switch of
transmitter.
(1) Received normal wave of LOCK switch.

No

Yes

Yes

No response

(2) Received normal wave of UNLOCK switch.

(3) Received normal wave of TRUNK switch.

(4) Compatibility of the recognition code or out from
synchronization of rolling code.*.

OFF

ON

OFF

ON

OFF

ON

OFF

ON

0.13 sec.

0.5 sec.

0.13 sec.

0.25 sec.

0.5 sec.

0.5 sec.

0.5 sec.

Transmitter faulty or wireless door lock
ECU faulty.
<Reference>



 Use other (normal) transmitter and check

with the diagnostic mode and in the case
that the check result shows the transmitter
faulty, it can be judged that wireless door
lock ECU is normal.

While receiving

In case of buzzer
outputs of (4)

In case of buzzer
outputs from (1) 

∼

 (3)

Not enter in

diagnostic

mode

–

DIAGNOSTICS

WIRELESS DOOR LOCK CONTROL SYSTEM

DI–445

597

1997 LEXUS ES300   (RM511U)

Check of the recognition code registration
function:
Check if it can set to rewrite mode or add
mode of the recognition code registration.

Yes

No

After registering the code, check
the operation and it is good of the
operation is normal.
(The rolling code has not been
synchronized.)

Check the terminal voltage of wireless door
lock ECU:
Check each following terminal.



 L       

  

UL3        



 IG



 CTY     



LSWD

NG

Vehicle wiring faulty.

OK

Wireless door lock ECU faulty.

Check the wireless door lock ECU:
Are the continuity and voltage between each terminal
of the connector connected to the wireless door lock
ECU and body grounding normal?

Terminal

No.

Item

Voltage

Standard

Voltage

10

13

Checking condition

Insert the key plate into the

ignition key cylinder 

→

Pull out.

Ignition switch OFF 

↔

 ON

0 V 

→

10 

∼

 14 V

0 V 

→

10 

∼

 14 V

Vehicle wiring faulty.

Wireless door lock ECU
faulty.

No

Yes

DI–446

–

DIAGNOSTICS

WIRELESS DOOR LOCK CONTROL SYSTEM

598

1997 LEXUS ES300   (RM511U)

Is the wave reaching range normal?
Depart about 1 m from the vehicle and press the switch of the transmitter.
While pressing on the transmitter switch, the buzzer should not keep working on.
(If pressing on about 20 sec. auto power off function will operate.)

Check the terminal voltage of wireless door lock
ECU:
Check the voltage each following terminal.



 L 

      

 UL3



 CTY       



 LSWD

Use other transmitter and check the wave reaching
range:

OK

NG

OK

NG

OK

NG

Vehicle wiring faulty.

Wireless door lock
ECU faulty.

Original transmitter
faulty

Wireless door lock
ECU faulty.

–

DIAGNOSTICS

WIRELESS DOOR LOCK CONTROL SYSTEM

DI–447

599

1997 LEXUS ES300   (RM511U)

HINT: The rolling code is the code changing at each time when the wave is transmitted from the transmitter
and is changing synchronized between transmitter side and ECU side.
When the rolling code is not synchronized between the transmitter and ECU, a symptom of ”Only LOCK op-
eration is available.”appears.
In this case, it goes back to normal by synchronizing the rolling code.
(The method to synchronize it is the same as of the registration of the recognition code.)

N13469

DI–448

–

DIAGNOSTICS

WIRELESS DOOR LOCK CONTROL SYSTEM

600

1997 LEXUS ES300   (RM511U)

1.

TRANSMITTER INSPECTION

1

Check the transmitter operation.

HINT: 
This inspection is not directly for the purpose of checking the ca-
pacity of the transmitter battery, but is performed when remote
control operation  becomes difficult or impossible, in order to as-
certain if this is caused by low battery capacity.
PREPARATION:
(a)

Using a screwdriver, pry outward the cover.

(b)

Remove the battery.

CHECK:
(a)

Connect 4 new 1.5 V dry–cell batteries in series. Connect
the battery 

 terminal to the battery receptacle side ter-

minal and the battery 



 terminal to the bottom terminal

to provide 6 V to the transmitter.

(b)

Push the wireless door lock remote control switch on the
side of the transmitter body and operate the door lock by
remote control.

OK:

Remote control operation possible. 

OK

Replace the battery for transmitter 
(See page 

DI–443

).

NG

Replace transmitter and registration of rec-
ognition code (See page 

DI–443

).