2000 LEXUS GS400 check engine

AC0XY±01
P01924
Ohmmeter
± AIR CONDITIONINGENGINE COOLANT TEMPERATURE (ECT) SWITCH
AC±93
2778 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
INSPECT ECT SWITCH
(a) Using an ohmmeter, check that no continuity exists be-
tween the terminals when the coolant temperature is
above 100 °C (212 °F).
If continuity exists, replace the switch.
(b) Using an ohmmeter, check that continuity exists between
the terminals when the coolant temperature is below
91 °C (196 °F).
If there no continuity exists, replace the switch.

D01012
SST
Q08511
SST
D01009
D01008
AT±4
± AUTOMATIC TRANSMISSIONEXTENSION HOUSING OIL SEAL
1952 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. INSTALL EXTENSION HOUSING REAR OIL SEAL
(a) Coat the lip of a new oil seal with MP grease.
(b) Using SST and a hammer, drive in the oil seal with the lip
facing downward.
SST 09309±37010
Oil seal depth from flat end: 2.0 mm (0.079 in.)
7. INSTALL TRANSMISSION OUTPUT FLANGE
(a) Using SST and a hammer, drive in a new oil seal.
SST 09950±60010 (09951±00350), 09950±70010
(09951±07100)
(b) Install the output flange.
(c) Using a 30 mm deeper socket wrench, install and torque
a new nut.
Torque: 126 N´m (1,280 kgf´cm, 93 ft´lbf)
HINT:
Shift the shift lever to P position.
(d) Using a chisel and hammer, stake the nut.
8. INSTALL PROPELLER SHAFT
(See page PR±10)
9. INSTALL FRONT EXHAUST PIPE AND HEAT INSULA-
TOR
1UZ±FE Engine: (See page EM±120)
2JZ±GE Engine: (See page EM±97)
10. FILL AND CHECK FLUID LEVEL
(See page DI±318)

DI3CO±10
± BODY ELECTRICALTHEFT DETERRENT SYSTEM
BE±141
2442 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
PRE±CHECK
1. THEFT DETERRENT SYSTEM
When the system is set to the theft deterrent mode and any of
the following conditions are met, the system sounds the horns
and flashes the headlights and the taillights for approx. 1 min-
ute.
At the same time the system locks all doors (If all door are not
locked at once, the system repeats door locking operation ev-
ery 0.55 seconds during the one minute alarm time).
There are 2 modes in this system, which are active mode and
passive mode.
All initial setting are performed in active mode. It can be
switched to passive mode by specified operation. (See step 4.
CHANGING METHOD OF PASSIVE MODE)
Condition:
Any of the doors (Including the engine hood and luggage
compartment door) is unlocked or opened without the
key. *1
The battery terminal is disconnected and reconnected.
The system receives panic signal from remote keyless
entry. *2
*1: Only active arming mode.
*2: When the ignition key is not inserted in the key cylin-
der.
There are 4 conditions in this system which are disarming
condition, disarming preparation condition, arming condition
and alarming condition.
(a) Disarming condition:
(1) When a user is near the vehicle.
(2) When the alarming function does not operate.
(3) When theft deterrent function is not performed.
(b) Disarming preparation condition:
(1) Time from a user locks a door to be leaves the ve-
hicle.
(2) Time until transferring to disarming condition.
(3) Theft deterrent function is not performed.
(c) Arming condition:
(1) When a user leaves the vehicle completely.
(2) When theft deterrent function is possible.

BE0GR±04
I04055
2 5
I04146
I04147
Not turned
UNLOCK
I04148
ON OFF BE±150
± BODY ELECTRICALTHEFT DETERRENT SYSTEM
2451 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT THEFT DETERRENT INDICATOR LIGHT OP-
ERATION
Connect the positive (+) lead from the battery terminal 2 and
negative (±) lead to terminal 5, and check that the warning light
lights up.
If operation is not as specified, replace the light control rheostat.
2. INSPECT THEFT DETERRENT INDICATOR LIGHT
CIRCUIT
(See page DI±808)
3. INSPECT THEFT DETERRENT HORN OPERATION
Connect the positive (+) lead from the battery to the terminal 1
and negative (±) lead to theft deterrent horn body, and check
that the theft deterrent horn blows.
If operation is not as specified, replace the horn.
4. INSPECT THEFT DETERRENT HORN CIRCUIT
(See page DI±804)
5. INSPECT LUGGAGE COMPARTMENT DOOR KEY
LOCK AND UNLOCK SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
Not turned±No continuity
UNLOCK1 ± 2Continuity
If continuity is not as specified, replace the switch.
6. INSPECT LUGGAGE COMPARTMENT DOOR KEY
LOCK AND UNLOCK SWITCH CIRCUIT
(See page DI±794)
7. INSPECT ENGINE HOOD COURTESY SWITCH CON-
TINUITY
Switch positionTester connectionSpecified condition
LOCK±No continuity
UNLOCK1 ± 2Continuity
If continuity is not as specified, replace the switch.
8. INSPECT ENGINE HOOD COURTESY SWITCH CIR-
CUIT
(See page DI±790)

BE0G8±09
I04266
1 2
BE±248
± BODY ELECTRICALENGINE IMMOBILISER SYSTEM
2549 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
INSPECTION TRANSPONDER KEY COIL CONTINUITY
Check that continuity exists between terminals 1 and 2.
If continuity is not as specified, replace the coil.

± BODY ELECTRICALTROUBLESHOOTING
BE±11
2312 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) The Key related power window operations does not operate with
driver side door key cylinder.
(Master switch operation is normal.)
TROUBLESHOOTING NO.3BE±111
Power window does not operate with multi±function transmitter.
(Windows operate normally with master switch.)TROUBLESHOOTING NO.4BE±111
Window moves down without being ordered during the up opara-
tion.TROUBLESHOOTING NO.5BE±111
POWER DOOR LOCK CONTROL SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
SymptomSuspect AreaSee page
All the doors cannot be locked or unlocked.
(Power Window Control System is normal.)1. Door Lock Control Switch
2. Wire Harness
3. Body No.1 ECUBE±131
±
DI±776
Only one side door lock control does not operate.
1. Door Lock Motor
2. Wire Harness
3. Each Door ECUBE±131
±
±
Door key related function does not operate.
1. Door Key Lock and Unlock Switch
2. Wire Harness
3. Each Door ECU
4. Body No.1 ECUBE±131
±
±
DI±776
Key confinement prevention function does not operate.
1. Key Unlock Warning Switch
2. Door Courtesy Switch
3. Wire Harness
4. Each Door ECUBE±31
BE±60
±
±
Luggage compartment door opener function does not operate.
1. Luggage Compartment Door Opener Switch
2. Luggage Compartment Door Opener Motor
3. Wire Harness
4. Body No.1 ECUBE±131
BE±131
±
DI±776
THEFT DETERRENT SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
SymptomSuspect AreaSee page
The system cannot be set.
1. Indicator Light
2. Key Unlock Warning Switch
3. Door Unlock Detection Switch
4. Engine Hood Courtesy Switch
5. Luggage Compartment Door Courtesy Switch
6. Wire Harness
7. Each Door ECU
8. Body No.1 ECUBE±150
BE±31
BE±131
BE±150
BE±60
±
±
DI±776
The system cannot be canceled when the ignition switch is turned
to ON with key.
1. Key Unlock Warning Switch
2. Ignition Switch
3. RAD NO.2 Fuse
4. Wire Harness
5. Body No.1 ECUBE±31
BE±31
BE±21
±
DI±776
The system cannot be canceled when the luggage compartment
door is unlocked with key.1. Luggage Compartment Door Courtesy Switch
2. Wire Harness
3. Body No.1 ECUBE±60
±
DI±776
The system does not operate when the engine hood is opened.
1. Engine Hood Courtesy Switch
2. Wire Harness
3. Body No.1 ECUBE±150
±
DI±776

± BODY ELECTRICALTROUBLESHOOTING
BE±15
2316 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
GARAGE DOOR OPENER SYSTEM
SymptomSuspect AreaSee page
The equipment of which code has been registered does not oper-
ate.1. Garage Door Opener Switch
2. Wire Harness
3. *BE±235
±
±
LED does not light up. (Even though either switch is pressed.)1. Garage Door Opener Switch
2. Wire HarnessBE±235
±
LED does not light up. (Only one switch is pressed.)Garage Door Opener SwitchBE±235
* As the GARAGE DOOR OPENER on the vehicle side seems to be normal, check the OPENER on the
equipment side, of which code has been registered.
ENGINE IMMOBILIZER SYSTEM
SymptomSuspect AreaSee page
Engine immobilizer system does not operate.See DIAGNOSIS SYSTEMDI±726
HORN SYSTEM
SymptomSuspect AreaSee page
Horn system does not operate.
1. HORN Fuse
2. Horn Relay
3. Horn Switch
4. Horn
5. Wire HarnessBE±21
BE±250
BE±250
BE±250
±
Horns blow all the time.
1. Horn Relay
2. Horn Switch
3. Wire HarnessBE±250
BE±250
±
One horn operates but the other horn does not operate.1. Horn
2. Wire HarnessBE±250
±
Horns operate abnormally.
1. Horn Relay
2. Horn
3. Wire HarnessBE±250
BE±250
±

I04038
I04039
BE±42
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
2343 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)8 ± Ground
Headlight dimmer switch HIGH beam or FLASHContinuity
1 ± GroundIgnition switch LOCK or ACCNo voltage
1 ± GroundIgnition switch ON or STARTBattery positive voltage
5 ± GroundEngine StopNo voltage
5 ± GroundEngine RunningBattery positive voltage
7 ± GroundConstantBattery positive voltage
9 ± GroundConstantBattery positive voltage
If circuit is specified, try replacing the relay with a new one.
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
16. INSPECT AUTOMATIC LIGHT CONTROL
AUTO ON:
(a) Turn the ignition switch ON.
(b) Turn the light control switch to AUTO.
(c) Gradually cover the top of the sensor.
(d) Check the accessory lights and the headlights should turn
ON.
17. INSPECT AUTOMATIC LIGHT CONTROL
AUTO OFF:
(a) Gradually expose the sensor.
(b) Check the headlights and the accessory lights should turn
OFF.
18. INSPECT LIGHT±OFF CONDITION
(a) Turn the ignition switch ON.
(b) Gradually cover the top of the sensor.
Lights auto ON:
(c) Check that the lights go off under the following conditions.
(1) Light control switch is OFF.
(2) The area surrounding the sensor gets bright.
(3) The driver's door is opened with the ignition switch
OFF.