Lexus RX300 (MCU15). Service manual - part 141

BE0GN–08

–

BODY ELECTRICAL

WIRELESS DOOR LOCK CONTROL SYSTEM

BE–111

LEXUS RX300   (RM785E)

PRE–CHECK

Make the vehicle in the initialized condition:
The initialized condition is the condition when the following conditions are satisfied.
(1) Key plate has not been inserted in the ignition key cylinder.
(2) All the doors are closed. (Door warning light is OFF.)
(3) All the doors are locked.

Under the standard operation, when repeating UNLOCK and LOCK switch 3 times or more alternately, check the
UNLOCK–LOCK operation from 3rd time onward.
D Following procedures are standard operation.
(1) Keep about 1 M away to the right direction from the outside handle of a driver’s seat.
(2) Face the transmitter toward the vehicle and press one of transmitter switches for about 1 sec.
<Reference>
D As of the security function, even the wireless function is normal, there may be the case that only UNLOCK opera-
tion will not work.
D As of the body customize function, if ”operation twice” has been set using LEXUS hand–held tester, only driver’s
seat is unlocked by unlock operation performed once.

Normal
<Reference>
D Operative distance may differ according to
an operator, the way of holding the transmitter
or position.
D Because weak electric wave is used, when
there is strong wave or noise in the used
frequency ,operation distance might be
shortened.

No

Yes

Only wireless function (Remote control) will not operate.
(If a new transmitter or a transmitter of the same type that works properly with the vehicle is not available.)

Check when pressing UNLOCK switch
and LOCK switch under standard
operation, that the transmitter LED
lights up once more.

No

Yes

Basic function check:

Transmitter LED inspection:

BE–112

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BODY ELECTRICAL

WIRELESS DOOR LOCK CONTROL SYSTEM

LEXUS RX300   (RM785E)

Replace the transmitter battery with a new or normal
one and check UNLOCK–LOCK function works under
the standard operation.
<Reference>
D The battery should be replaced by only the shops with
sufficient skill as new or normal battery is necessary.
D Battery quality can be judged by checking the rem-
nant volume of the battery.

Yes

Battery faulty.

No

Make the vehicle be in the initialized condition.

Enter into the self diagnostic mode.
If operating door control receiver in the order of 1 through 2, the mode turns to diagnostic mode.
(1) Insert the key plate in the ignition key cylinder and pull out, then insert it again and turn ignition switch
OFF → ON → OFF once within 5 seconds after pulling out.
(2) After completing the procedure within 30 seconds, turn the ignition switch OFF → ON → OFF 9 times.
HINT:
In the case that either (1) or (2) condition is not satisfied, transfer to normal mode.
<Reference>
When completing self diagnostic mode, turn the ignition switch ON.
LOCK and UNLOCK operation and output of luggage door opener signal are not performed under the self
diagnostic mode.

1st time

9th time

ON

OFF

Transmitter battery check:

Inspection start by using self diagnostic mode:

within.
30 secs.

within.
5 secs.

1

2

8

9

Key plate
not inseted

Key plate
inseted

Ignition
switch

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BODY ELECTRICAL

WIRELESS DOOR LOCK CONTROL SYSTEM

BE–113

LEXUS RX300   (RM785E)

No

No
(Not entered in self
diagnostic mode)

Is the method to enter into the
diagnostic mode correct?

Self diagnostic mode operation check:

Yes
(Entered in self diagnostic mode)

After the self diagnostic mode input operation has
been performed, check that the buzzer chirps.

ON

OFF

Buzzer

Ignition switch OFF

0.13 secs.

0.5 secs.

Is the chirping function of operation
confirmation room light normal?

Check room light.

Check that continuity exists between
connector terminal A3 of MPX body ECU
on the vehicle side and ground by
inserting the key plate into the ignition
key cylinder.

Key unlock warning switch inspection:

Yes

Yes

No

Check key unlock warning switch
(See page BE–26).

Self diagnostic mode check:

Check that how the buzzer chirps when pressing
each transmitter switch.

Room Light
      ON

OFF

0.25 secs.0.5 secs.

(1) Receiver normal wave of LOCK switch.

OFF

0.25 secs.

0.25 secs

(2) Receiver normal wave of UNLOCK switch.

0.5 secs.

ON

OFF

(3) Incompatibility of the recognition code or out
from synchronization of rolling code.

While receiving

<Reference>:
While turning the ignition switch ON in the self
diagnostic mode, the mode returns to normal mode.

Room Light

(1)or (2) are output.

(3) is output.
(All room light response
is same.)

Recognition code registration function check:

Check that it is possible to enter into
rewrite mode or add mode.
(Refer to ”Wireless door lock receiver and
transmitter” – ”Recognition code registration”.)

Wireless door lock operates
normally when recognition code
is registered.

No response from buzzer

Room Light
      ON

BE–114

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BODY ELECTRICAL

WIRELESS DOOR LOCK CONTROL SYSTEM

LEXUS RX300   (RM785E)

Transmitter faulty or wireless door lock receiver
faulty.
<Reference>
Check the wave reaching range with another
transmitter (normal). When the range is normal,
transmitter defection is detected, the range is
not normal, wireless door lock receiver defection
is detected.

The wave reaching range check:

Is the wave reaching range normal?
(1 M area around vehicle)
(While the transmitting switch is pressed,
(approx. 20 secs.) the buzzer chirps continuously.
After 20 secs., repress the switch again.)

No

Other body control system faylty.
(Transmitter and receiver are normal.)

Yes

No

Wireless door control receiver check:

Check that continuity exists between the receiver ter-
minal PRG and body ECU terminal PRG.
Check that continuity exists between the receiver ter-
minal RDA and body ECU terminal RDA.

Yes

Wire harness faulty (short circuit).
Between the receiver terminal RDA and
body ECU terminal RDA.

Yes

RDA terminal open circuit.

No

Check RDA terminal circuit.

Check that the voltage of RDA is 10 to 14 V
(without transmitting).

No

When pressing each switch of
the new or normal transmitter
used in the same type vehicle,
check that all buzzers chirp
in the same way.

Transmitter faulty.

Yes