Page 2 of 1111
AC±2
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
2687 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
9. SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
The Lexus GS 300/ 400 is equipped with an SRS (Supplemen-
tal Restraint System) such as the driver and passenger airbag.
Failure to carry out service operations in the correct sequence
could cause the SRS to unexpectedly deployed during servic-
ing, possibly leading to a serious accident. Further, if a mistake
is made in servicing the SRS, it is possible the SRS may fail to
operate when required. Before servicing ( including removal or
installation of parts, inspection or replacement), be sure to read
the following item carefully, then follow the correct procedure
described in repair manual.
Page 3 of 1111

AC0W8±01
N13795
Quick Disconnect
Adapter
Charging
Service ValveHose
N13794
Vacuum Pump
Vacuum Pump Adapter
N13791
Low Pressure
Service Valve
Vacuum Pump Adapter High Pressure
Service ValveManifold
Gauge
Set
AC±10
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
2695 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
EVACUATING
1. CONNECT QUICK DISCONNECT ADAPTER TO
CHARGING HOSES
2. REMOVE CAPS FROM SERVICE VALVES ON RE-
FRIGERANT LINES
3. SET ON MANIFOLD GAUGE SET
(a) Close both hand valves of manifold gauge set.
(b) Connect the quick disconnect adapters to the service
valves.
4. EVACUATE AIR FROM REFRIGERATION SYSTEM
(a) Connect the vacuum pump adapter to the vacuum pump.
(b) Connect the center hose of the manifold gauge set to the
vacuum pump adapter.
(c) Open both the high and low hand valves and run the vacu-
um pump.
(d) After 10 minutes or more, check that the low pressure
gauge indicates 750 mmHg (30 in. Hg) or more.
HINT:
If the reading is 750 mmHg (30 in. Hg) or more, close both hand
valves of manifold gauge set and stop the vacuum pump.
Check the system for leaks and repair if necessary.
(e) Close both the high and low hand valves and stop the vac-
uum pump.
(f) Leave the system in this condition for 5 minutes or more
and check that there is no gauge indicator.
Page 4 of 1111

AC0W9±01
N13793
Charging Cylinder High Pressure
Service Valve Low Pressure
Service ValvePush
Air
N13792
Gas Leak
Detector
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±11
2696 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
CHARGING
1. INSTALL CHARGING CYLINDER
HINT:
When handling the charging cylinder, always follow the direc-
tions given in the instruction manual.
(a) Charge the proper amount of refrigerant into the charging
cylinder.
(b) Connect the center hose to the charging cylinder.
CAUTION:
Do not open both high and low hand valves of manifold
gauge set.
(c) Open the valve of charging cylinder.
(d) Press the valve core on the side of manifold gauge and
expel the air inside of the center hose.
2. INSPECT REFRIGERATION SYSTEM FOR LEAKS
(a) Open the high pressure hand valve and charge refriger-
ant.
(b) When the low pressure gauge indicates 98 kPa
(1 kgf/cm
2, 14 psi) close the high pressure hand valve.
(c) Using a gas leak detector, check the system for leakage.
If leak is found, repair the faulty component or connection.
CAUTION:
Use the refrigerant recovery/ recycling machine to recover
the refrigerant whenever replacing parts.
Page 5 of 1111
N13790
Low Pressure
Service Valve
High Pressure
Service Valve
AC±12
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
2697 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSTALL CHARGING CYLINDER
HINT:
When handling the charging cylinder, always follow the direc-
tions given in the instruction manual.
(a) Charge the proper amount of refrigerant into the charging
cylinder.
(b) Connect the center hose to the charging cylinder.
CAUTION:
Do not open both high and low hand valves of manifold
gauge set.
(c) Open the valve of charging cylinder.
(d) Press the valve core on the side of manifold gauge and
expel the air inside of the center hose.
A fully charged system is indicated by the sight glass being free
of any bubbles.
4. SET OFF MANIFOLD GAUGE SET
(a) Close both hand valves of manifold gauge set.
(b) Disconnect the quick disconnect adapters from the ser-
vice valves.
5. INSTALL CAPS TO SERVICE VALVES ON REFRIGER-
ANT LINES
Page 10 of 1111
I02353
GS400:
Low Pressure
Charging HoseHigh Pressure
Charging Hose
I02354
GS300:
Low Pressure
Charging HoseHigh Pressure
Charging HoseAC0WE±01
N04392
Sleeve
± AIR CONDITIONINGMANIFOLD GAUGE SET
AC±17
2702 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
MANIFOLD GAUGE SET
SET ON
1. CONNECT CHARGING HOSES TO MANIFOLD
GAUGE SET
Tighten the nuts by hand.
CAUTION:
Do not connect the wrong hoses.
2. CONNECT QUICK DISCONNECT ADAPTERS TO
CHARGING HOSES
Tighten the nuts by hand.
3. CLOSE BOTH HAND VALVES OF MANIFOLD GAUGE
SET
4. REMOVE CAPS FROM SERVICE VALVE ON REFRIG-
ERANT LINES
5. CONNECT QUICK DISCONNECT ADAPTERS TO SER-
VICE VALVES
HINT:
Push the quick disconnect adapter onto the service valve, then
slide the sleeve of the quick disconnect adapter downward to
lock it.
Page 11 of 1111
AC0WF±01
N06553
AC±18
± AIR CONDITIONINGMANIFOLD GAUGE SET
2703 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
SET OFF
1. CLOSE BOTH HAND VALVES OF MANIFOLD GAUGE
SET
2. DISCONNECT QUICK DISCONNECT ADAPTERS
FROM SERVICE VALVES ON REFRIGERANT LINE
HINT:
Slide the sleeve of the quick disconnect adapter upward to un-
lock the adapter and remove it from the service valve.
3. INSTALL CAPS TO SERVICE VALVES ON REFRIGER-
ANT LINES
Page 136 of 1111

BE01I±09
± BODY ELECTRICALBODY ELECTRICAL SYSTEM
BE±1
2302 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
BODY ELECTRICAL SYSTEM
PRECAUTION
HINT:
Take care to observe the following precautions when performing inspections or removal and replacement
of body electrical related parts.
1. HEADLIGHT SYSTEM
Halogen bulbs have pressurized gas inside and require special handling. They can burst if scratched
or dropped. Hold a bulb only by its plastic or metal case. Don't touch the glass part of a bulb with bare
hands.
When high voltage socket of discharge headlight is touched with the light control switch HEAD, high
voltage of 20,000 V is momentarily generated. This might lead to a serious accident.
Never connect the tester to the high voltage socket of discharge headlight for measurement, as this
leads to a serious accident because of high voltage.
When performing operation related to the discharge headlight, make sure to do it in the place with no
water of rain to prevent electric shock, with light control switch OFF, battery terminal removed, connec-
tor of light control ECU disconnected.
When performing operation related to the discharge headlight, make sure to do it after assembling has
been completely over and never light up without a bulb installed.
Do not light up the discharge headlight using another power source except vehicle's.
When there is a defect on the discharge headlight or any shock has been applied to it, replace the light
with a new one.
Even if the light operates normally, there is a possibility that the fail±safe function works.
2. SRS (SUPPLEMENTAL RESTRAINT SYSTEM)
The LEXUS GS300/ 400 is equipped with an SRS (Supplemental Restraint System) such as the driver airbag
and front passenger airbag. Failure to carry out service operation in the correct sequence could cause the
SRS to unexpectedly deploy during servicing, possibly leading to a serious accident. Before servicing (in-
cluding removal or installation of parts, inspection or replacement), be sure to read the precautionary notices
in the RS section.
3. COMBINATION METER SYSTEM
The cold cathode tube connectors (Connector ºKºand ºLº) in the combination meter are charged with high
voltage AC current when power is supplied, so do not touch them when they are charged.
Page 236 of 1111

V08418
Turn ignition Key from LOCK position to ACC position.
Troubleshooting for ANTI±THEFT SYSTEM
Display A:
ID Number is set.Display E:
ANTI±THEFT SYSTEM opera-
tion condition. (ID number input
error 10 times or more.)Display B
ºSECº display disappears after 1
second.Radio switch ON.
Take to designated radio
service station.Display BDisplay D
Refer to each
malfunction item.Normal
operation.
Radio switch ON. Normal operation.
Cancel ID number, refer to each malfunction item.
Ye s
No
OK
NG
ANTI±THEFT SYSTEM operation condition. (ID number input error 9 times or less.)
Input ID number to cancel ANTI±THEFT SYSTEM, and check display.
Display A"B Display B Display E
Display C"A
Radio switch ON.Refer to each
malfunction item.Take to designated
radio service station.ANTI±THEFT SYSTEM not can-
celled. (ID number input error 10
times or less.)
Display D
ANTI±THEFT SYSTEM cancelled.
Check audio system again.Normal operation.
OK
NG
Cancel ID number, refer to each malfunction item.
Liquid Crystal Display (LCD) or VFD for Audio System
Display ºAº Display ºBº Display ºCº
Display ºDº Example:Display ºEº
2 DIN Type
1 DIN TypeBlank
No Illumination
2 DIN Type
1 DIN Type 2 DIN Type
1 DIN Type Error Times2 DIN Type 1 DIN Type
Radio Display
1 DIN Type 2 DIN Type
HINT:
Refer to Owner's Manual for operation details of ANTI±THEFT SYSTEM.
When the ID number has been cancelled, reset the same number after completing the operation, or
inform the customer that it has been cancelled.
± BODY ELECTRICALAUDIO SYSTEM
BE±197
2498 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)