ECU LEXUS GS400 2000 Service Owner's Manual

N09348
ECULEXUS hand±held tester
LEXUS Break±out±box
± BODY ELECTRICALTHEFT DETERRENT SYSTEM
BE±147
2448 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(b) Transfer to active mode:
In each passive mode, when ºdisarming condition of ac-
tive mode " arming preparation transfer conditionº is
met, the active mode transfers to each condition. In this
case, active mode continues till disarming condition.
Passive mode when transfer condition is
met.Active mode transfer condition
Disarming conditionArming preparation condition
Arming preparation conditionArming preparation condition
Arming condition
(During entry delay time)Arming condition
(After alarming time has elapsed, arming
condition)
Alarming conditionAfter alarming time has elapsed, arming
condition
4. CHANGING METHOD OF PASSIVE MODE (ON or OFF)
Using a hand±held tester, the mode can be changed to the pas-
sive mode.
5. ECU TERMINAL VALUES MEASUREMENT BY USING
LEXUS BREAK±OUT±BOX AND LEXUS HAND±HELD
TESTER
(a) Hook up the LEXUS break±out±box and LEXUS hand±
held tester to the vehicle.
(b) Read the ECU input/ output values by following the
prompts on the tester screen.
(c) Please refer to the LEXUS hand±held tester has a ºSnap-
shotº function. This records the measured data and is ef-
fective in the diagnosis of intermittent problems.

N09348
ECULEXUS hand±held tester
LEXUS Break±out±box
± BODY ELECTRICALTHEFT DETERRENT SYSTEM
BE±149
2450 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
7. ECU TERMINAL VALUES MEASUREMENT BY USING
LEXUS BREAK±OUT±BOX AND LEXUS HAND±HELD
TESTER
(a) Hook up the LEXUS break±out±box and LEXUS hand±
held tester to the vehicle.
(b) Read the ECU input/ output values by following the
prompts on the tester screen.
(c) Please refer to the LEXUS hand±held tester has a ºSnap-
shotº function. This records the measured data and is ef-
fective in the diagnosis of intermittent problems.

BE0GN±01
BE±152
± BODY ELECTRICALWIRELESS DOOR LOCK CONTROL SYSTEM
2453 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
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.
(4) Wireless door lock control switch (Buzzer switch) is ON.
Under the standard operation, when repeating UNLOCK and LOCK switch 3 times or more alternately, check the
UNLOCK±LOCK operation from 3rd time onward.

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.


As of the security function, even the wireless function is normal, there may be the case that only UNLOCK opera-
tion will not work.

As of the body customize function, if ºoperation twiceº has been set using LEXUS hand±held tester, only driver's
seat is unlocked by unlock operation performed once.
Normal


Operative distance may differ according to
an operator, the way of holding the transmitter
or position.

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.
NoYe s
Basic function check:
Transmitter LED inspection:

BE±154
± BODY ELECTRICALWIRELESS DOOR LOCK CONTROL SYSTEM
2455 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
No
No
(Not entered in self
diagnostic mode)Is the method to enter into the
diagnostic mode correct?
Self diagnostic mode operation check:
Ye s
(Entered in self diagnostic mode)
After the self diagnostic mode input operation has
been performed, check that the buzzer chirps.
ON
OFF BuzzerIgnition switch OFF
0.13 sec. 0.5 sec.
Is the chirping function of operation
confirmation buzzer normal?
Check door control buzzer.
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:
Ye s Ye s
No
Check key unlock warning switch.
Self diagnostic mode check:
Check that how the buzzer chirps when pressing
each transmitter switch.
ON
OFF Buzzer
0.13 sec.0.5 sec.
(1) Receiver normal wave of LOCK switch.
ON
OFF Buzzer
0.13 sec.
0.25 sec.
(2) Receiver normal wave of UNLOCK switch.
0.5 sec.
ON
OFF Buzzer
(3) Receiver normal wave of luggage door switch.
0.5 sec.0.5 sec.
ON
OFF (4) Incompatibility of the recognition code or out
from synchronization of rolling code.
While receiving
:
While turning the ignition switch ON in the self
diagnostic mode, the mode returns to normal mode. Buzzer
(1), (2) or (3) are output.(4) is output.
(All buzzer's response
is same.)
Recognition code registration function check:
Check that it is possible to enter into
rewrite mode or add mode.
(Refer to ºWireless door lock receiver and
transmitterº ± ºRecognition code registrationº.)
Wireless door lock operates
normally when recognition code
is registered.
No response from buzzer

± BODY ELECTRICALWIRELESS DOOR LOCK CONTROL SYSTEM
BE±155
2456 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
Transmitter faulty or wireless door lock receiver
faulty.

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.)
NoOther body control system faylty.
(Transmitter and receiver are normal.)
Ye s
No
Wireless door control receiver check:
Check the diagnosis. (wirelss door lock signal error)
(Refer to ºMultiplex communication systemº)
Check that diagnostic code 42 is output.
Ye s
Wire harness faulty (short circuit)
Between the receiver terminal 4 (RDA) and
body ECU terminal B14 (RDA).Ye s
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.
Ye s
Using SST, connect terminal Tc and E1 of DLC1.

BE±156
± BODY ELECTRICALWIRELESS DOOR LOCK CONTROL SYSTEM
2457 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
Ye s
Wireless door control receiver power source check:
Check that there is 4.5 ± 5.5 V voltage at the
connector terminal 3 (RCO) of wireless door control
receiver under the vehicle initialized condition.
(1) Check that the control receiver voltage becomes
0 V during transmitting.
(2) When RCO is turned ON compulsoring with a
LEXUS hand±held tester, check that the wireless door
lock control receiver voltage becomes 0 V.
No
ECU±B1 and MPX±B, or P FR DOOR fuse
or wire harness faulty.
Ye s
+B power source check:
Check that there is constantly10 to 14 V voltage at the
connector terminal 1 (+B) of wireless door control
receiver.
No
Wire harness faulty.
Body ground open and contact error.
Ye s
Body ground check:
Check that continuity exists between the connector
terminal 7 (GND) of the wireless door control receiver
and body ground.
No
Wireless door control receiver faulty.Wire harness faulty (open circuit)
Between the receiver terminal 3 (CONT) and
body ECU terminal B5 (RCO).

I04026

Engine Room No.1 Junction Block
Fuses Relays
1. MAIN H±Fuse
2. FL ABS NO.1 H±Fuse
3. ALT H±Fuse
4. ABS NO.2 H±Fuse
5. H±LP CLN H±Fuse
6. RAD NO.1 Fuse
7. ALT±S Fuse
8. EFI Fuse
9. TURN HAZ Fuse
10. TEL Fuse
11. AM2 Fuse
13. HORN Fuse 12. ETCS Fuse
14. MPX±B Fuse
15. ECU±B1 Fuse
16. HTR FuseB. Starter Relay A. Headlight Control Relay
C. EFI Relay
17. FAN MAIN H±Fuse
18. CDS FAN H±Fuse
20. H±LP R LWR Fuse 19. RAD FAN H±Fuse
21. H±LP L LWR Fuse
22. H±LP R UPR Fuse
23. H±LP L UPR Fuse1
2 3 4 5 6 7 8 9 10 11 12 13
14 15
16 18 17 19
20 21 22 23 A
BC
± BODY ELECTRICALPOWER SOURCE
BE±17
2318 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

I04029
Fuses
Relays 1. AM1 H±Fuse
2. WASHER Fuse
3. FOG Fuse
4. TAIL Fuse
B. Taillight Control Relay A. Fog Light Relay
C. Body ECU No.2
Driver Side Instrument Panel Junction Block
5. SRS±ACC Fuse
6. GAUGE Fuse
7. FUEL OPN Fuse
8. D FR DOOR Fuse
9. PANEL Fuse
10. HTR Fuse
11. SRS±B Fuse
12. P/SEAT (D) Fuse
13. RAD NO.2 Fuse
14. WIP Fuse
15. OBD Fuse
16. STOP Fuse
17. CIG Fuse
18. ECU±IG Fuse
19. STARTER Fuse
20. IGN Fuse
21. D FR DOOR Fuse
2
21 34 5
678 9
10 11 12 13
14 15 16 17
18 19 20AB
C 1
± BODY ELECTRICALPOWER SOURCE
BE±19
2320 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

I04030
Fuses
Relays 1. DEF H±Fuse
2. ±
3. ±
4. MIR HTR Fuse
A. Ignition Main Relay
B. Mirror Heater Relay
E. Body ECU No.1
Passenger Side Instrument Panel Junction Block
5. ±
6. ±
7. S/ROOF Fuse
8. P FR DOOR Fuse
9. ±
10. ±
11 .
12. P/SEAT (P) Fuse
13. DOME Fuse
14. SEAT HTR Fuse
15. ±
16. TV Fuse
17. ECU±B2 Fuse
18. ±
19. ±
20. ±
21. P FR DOOR Fuse
2
21 34 5
67 8 9
10 11 12 13
14 15 16 17
18 19 20AB
E
C. Defogger Relay
D. Heater Relay
CD
1
BE±20
± BODY ELECTRICALPOWER SOURCE
2321 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

BE±164
± BODY ELECTRICALWIRELESS DOOR LOCK CONTROL SYSTEM
2465 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
Within
3 secs.
Turn the ignition switch from ON to LOCK at approx. 1 sec. interval 1 to 5 times to select the mode.
Pull out the key plate from the ignition key cylinder.
When add mode or rewrite mode
is selected.When confirmation
mode is selected.
ON
ONON
LOCK
LOCKLOCK
Approx.
1 sec.Approx.
1 sec. Approx. 1 sec.Approx.
1 sec.Approx.
1 sec.
Add mode
Rewrite modeConfirmation mode
ON ± LOCK change occurs 1 time
ON ± LOCK change occurs 2 timesON ± LOCK change occurs 3 times
MPX body ECU automatically performs
the LOCK±UNLOCK operation once
or twice at 1 sec. interval to iniform the
operator that either the add mode or
rewrite mode has been selected.
LOCK±UNLOCK occurs once
LOCK±UNLOCK occurs twice
Indicates that add mode has been selected.
Indicates that rewrite mode has been
selected.
1 sec.
LOCK
1 sec.1 sec.
LOCK
UNLOCK
UNLOCK
LOCK
2 secs.2 secs.
UNLOCK MPX body ECU automatically performs the
LOCK±UNLOCK operation 1 to 4 times at
2 sec. interval to inform the operator of
the number of the registered codes.
HINT:
When the number of the registered code
is 0, the operation is automatically
performed 5 times.
Example:
When the operation is performed twice, it
directs that 2 types of recognition code
have been registered.
1st time 2nd time
Registration of recognition code (Confirmation
mode and prohibition mode) is completed.
ON
LOCK
Approx.
1 sec.Approx.
1 sec.
Prohibition mode
ON ± LOCK change occurs 5 times
When prohibition
mode is selected.