2000 LEXUS GS400 Service Repair Manual

I04075
Driver Side ECU
From Back Side
1 9
10 18
8
17
Wire Harness Side
I04183
Driver Side ECU
From Back Side 7
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
BE±119
2420 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. INSPECT ONE TOUCH POWER WINDOW SYSTEM/
CURRENT OF CIRCUIT (Using an ammeter)
(a) Disconnect the connector from the driver door ECU.
(b) Connect the positive (+) lead from the ammeter to termi-
nal 8 on the wire harness side connector and the negative
(±) lead to negative (±) terminal of the battery.
(c) Connect the positive (+) lead from the battery to terminal
17 on the wire harness side connector.
(d) As the window goes down, check that the current flow is
approximately 7 A.
(e) Check that the current increases up to approximately
14.5 A or more when the window stops going down.
HINT:
The PTC opens some 4 ± 90 seconds after the window stops
going down, so that check must be made before the PTC oper-
ates.
If the operation is as specified, replace the driver door ECU.
5. INSPECT ONE TOUCH POWER WINDOW SYSTEM/
CURRENT OF CIRCUIT (Using an ammeter with a cur-
rent±measuring probe)
(a) Remove the driver door ECU with connectors connected.
(b) Attach a current±measuring probe to terminal 7 of the
wire harness.
(c) Turn the ignition switch ON and set the power window
switch in the down position.
(d) As the window goes down, check that the current flow is
approximately 7 A.
(e) Check that the current increases up to approximately
14.5 A or more when the window stops going down.
HINT:
The PTC opens some 4 ± 90 seconds after the window stops
going down, so that check must be made before the PTC oper-
ates.
If operation is as specified, replace the driver door ECU.

I04123
I04119
2
3
I01200
2 1
35
2 5
1 3
I05474
1
2
BE±120
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
2421 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. INSPECT POWER WINDOW SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
AUTO3 ± 5Continuity
UP3 ± 6Continuity
OFF±No continuity
DOWN3 ± 4Continuity
If continuity is not as specified, replace the switch.
7. INSPECT POWER WINDOW SWITCH CIRCUIT
Passenger side: (See page DI±908)
Rear LH side: (See page DI±936)
Rear RH side: (See page DI±953)
8. INSPECT POWER WINDOW SWITCH ILLUMINATION
Connect the positive (+) lead from the battery to terminal 3 and
the negative (±) lead to terminal 2, and check that the indicator
light lights up.
If operation is not as specified, replace the switch.
9. INSPECT POWER MAIN RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
10. INSPECT POWER MAIN RELAY CIRCUIT
(See page BE±21)
11. Driver 's door:
INSPECT POWER WINDOW MOTOR OPERATION
(a) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 2, and check that
the motor turns clockwise.

I054751
2
I05476
1
2
I054771
2
I04124
13
I04125
13
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
BE±121
2422 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(b) Reverse the polarity, check that the motor turns counter-
clockwise.
If operation is not as specified, replace the motor.
12. Driver 's door:
INSPECT POWER WINDOW MOTOR CIRCUIT
(See page DI±876)
13. Front passenger's door:
INSPECT POWER WINDOW MOTOR OPERATION
(a) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 2, and check that
the motor turns clockwise.
(b) Reverse the polarity, check that the motor turns counter-
clockwise.
If operation is not as specified, replace the motor.
14. Front passenger's door:
INSPECT POWER WINDOW MOTOR CIRCUIT
(See page DI±910)
15. Rear left side door:
INSPECT POWER WINDOW MOTOR OPERATION
(a) Connect the positive (+) lead from the battery to terminal
3 and the negative (±) lead to terminal 1, and check that
the motor turns clockwise.
(b) Reverse the polarity, check that the motor turns counter-
clockwise.
If operation is not as specified, replace the motor.

I04126
13
I04127
13
I04128
within
4 to 40 seconds
21
I04129
2 within
60 seconds
1
I04130
within
4 to 40 seconds
3 1
BE±122
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
2423 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
16. Rear right side door:
INSPECT POWER WINDOW MOTOR OPERATION
(a) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 3, and check that
the motor turns clockwise.
(b) Reverse the polarity, check that the motor turns counter-
clockwise.
If operation is not as specified, replace the motor.
17. Front door:
INSPECT POWER WINDOW MOTOR PTC OPERA-
TION
(a) Disconnect the connector from the master switch.
(b) Connect the positive (+) lead from the battery to terminal
2 and the negative (±) lead to terminal 1 on the wire har-
ness side connector and raise the window to full closed
position.
(c) Continue to apply voltage, check that there is a PTC op-
eration noise within approximately 4 to 90 seconds.
(d) Reverse the polarity, check that the window begins to de-
scend within approximately 60 seconds.
If operation is not as specified, replace the motor.
18. Rear door:
INSPECT POWER WINDOW MOTOR PTC OPERA-
TION
(a) Disconnect the connector from the rear door ECU.
(b) Connect the positive (+) lead from the battery to terminal
3 and the negative (±) lead to terminal 1 on the wire har-
ness side connector, and raise the window to full closed
position.
(c) Continue to apply voltage, check that there is a PTC op-
eration noise within approximately 4 to 90 seconds.

I04131
3 within
60 seconds
1
I05102
1
2
4
5
I05103
1
2
4
5
I05104
1
2
4
5
I05105
1
2
4
5
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
BE±123
2424 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(d) Reverse the polarity, check that the window begins to de-
scend within approximately 60 seconds.
If operation is not as specified, replace the motor.
19. Driver 's door (window up):
INSPECT JAM PROTECTION LIMIT SWITCH OPERA-
TION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 4 and the negative (±) lead to terminal 5.
(b) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 2.
(c) Check that the continuity exists when the window goes
up.
(d) Check that the no continuity exists when the window is in
the fully closed position.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.
20. Driver 's door (window down):
INSPECT JAM PROTECTION LIMIT SWITCH OPERA-
TION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 4 and the negative (±) lead to terminal 5.
(b) Connect the positive (+) lead from the battery to terminal
2 and the negative (±) lead to terminal 1.
(c) Check that the continuity exists when the window goes
down.
(d) Check that the no continuity exists when the window is in
the fully opened position.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.
21. Driver 's Door:
INSPECT JAM PROTECTION LIMIT SWITCH CIRCUIT
(See page DI±878)

I05106
1
2
4
5
I05107
1
2
4
5
I05108
1
2
4
5
I05109
1
2
4
5
I05110
12
3
6
BE±124
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
2425 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
22. Front passenger's door (window up):
INSPECT JAM PROTECTION LIMIT SWITCH OPERA-
TION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 4 and the negative (±) lead to terminal 5.
(b) Connect the positive (+) lead from the battery to terminal
2 and the negative (±) lead to terminal 1.
(c) Check that the continuity exists when the window goes
up.
(d) Check that the no continuity exists when the window is in
the fully closed position.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.
23. Front passenger's door (window down):
INSPECT JAM PROTECTION LIMIT SWITCH OPERA-
TION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 4 and the negative (±) lead to terminal 5.
(b) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 2.
(c) Check that the continuity exists when the window goes
down.
(d) Check that the no continuity exists when the window is in
the fully opened position.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.
24. Passenger 's Door:
INSPECT JAM PROTECTION LIMIT SWITCH CIRCUIT
(See page DI±912)
25. Rear LH side door (window up):
INSPECT JAM PROTECTION LIMIT SWITCH OPERA-
TION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 2 and the negative (±) lead to terminal 6.
(b) Connect the positive (+) lead from the battery to terminal
3 and the negative (±) lead to terminal 1.
(c) Check that the continuity exists when the window goes
up.

I05111
12
3
6
I05112
12
3
6
I05113
12
3
6
I05114
12
3
6
I05115
12
3
6
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
BE±125
2426 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(d) Check that the no continuity exists when the window is in
the fully closed position.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.
26. Rear LH side door (window down):
INSPECT JAM PROTECTION LIMIT SWITCH OPERA-
TION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 2 and the negative (±) lead to terminal 6.
(b) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 3.
(c) Check that the continuity exists when the window goes
down.
(d) Check that the no continuity exists when the window is in
the fully opened position.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.
27. Rear RH side door (window up):
INSPECT JAM PROTECTION LIMIT SWITCH OPERA-
TION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 2 and the negative (±) lead to terminal 6.
(b) Connect the positive (+) lead from the battery to terminal
3 and the negative (±) lead to terminal 1.
(c) Check that the continuity exists when the window goes
up.
(d) Check that the no continuity exists when the window is in
the fully closed position.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.

I05116
12
3
6
I05117
12
3
6
I05118
1
2
3
5
I05119
1
2
3
5
I05120
1
2
3
5
BE±126
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
2427 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
28. Rear RH side door (window down):
INSPECT JAM PROTECTION LIMIT SWITCH OPERA-
TION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 2 and the negative (±) lead to terminal 6.
(b) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 3.
(c) Check that the continuity exists when the window goes
down.
(d) Check that the no continuity exists when the window is in
the fully opened position.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.
29. Driver 's door:
INSPECT JAM PROTECTION PULSE SWITCH OP-
ERATION
(a) Connect the positive (+) lead from the TOYOTA electrical
tester to terminal 3 and the negative (±) lead to terminal
5.
(b) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 2.
(c) Check that pulse is generated during the motor running.
(d) Reverse the polarity and check that pulse is generated.
If operation is not as specified, replace the motor.
NOTICE:
If connecting the wire harness wrongly, the sensor might
be damaged so caution is necessary.
30. Driver 's door:
INSPECT JAM PROTECTION PULSE SWITCH CIR-
CUIT
(See page DI±880)
31. Front passenger's door:
INSPECT JAM PROTECTION PULSE SWITCH OP-
ERATION
(a) Connect the positive (+) lead from the TOYOTA electrical
tester to terminal 3 and the negative (±) lead to terminal
5.
(b) Connect the positive (+) lead from the battery to terminal
2 and the negative (±) lead to terminal 1.
(c) Check that pulse is generated during the motor running.