2000 LEXUS GS400 sensor

RS01Z±02
H02570
H02571Spiral Cable
H02572
H02573
H03446
RS±2
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
2233 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
OPERATION
1. STEERING WHEEL PAD (with AIRBAG)
The inflater and bag of the SRS are stored in the steering wheel
pad and cannot be disassembled. The inflater contains a squib,
igniter charge, gas generant, etc., and inflates the bag when
instructed by the airbag sensor assembly.
2. SPIRAL CABLE (in COMBINATION SWITCH)
A spiral cable is used as an electrical joint from the vehicle body
side to the steering wheel.
3. FRONT PASSENGER AIRBAG ASSEMBLY
The inflater and bag of the SRS are stored in the front passen-
ger airbag assembly and cannot be disassembled. The inflater
contains a squib, igniter charge, gas generant, etc., and inflates
the bag when instructed by the airbag sensor assembly.
4. SIDE AIRBAG ASSEMBLY
The inflater and bag of the SRS side airbag are stored in the
side airbag assembly and cannot be disassembled. The inflater
contains a squib, igniter charge, gas generant, etc., and inflates
the bag when instructed by the side airbag sensor assembly.
5. SEAT BELT PRETENSIONER
The seat belt pretensioner system is a component of the front
seat outer belt. The pretensioner contains a squib, gas gener-
ant, wire, piston, etc., and operates in the event of a frontal colli-
sion.

H02575
H02574
H02700
H02576
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS±3
2234 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. SRS WARNING LIGHT
The SRS warning light is located on the combination meter. It
goes on to alert the driver of trouble in the system when a mal-
function is detected in the airbag sensor assembly. In normal
operation conditions when the ignition switch is turned to the
ACC or ON position, the light goes on for apporx. 6 seconds and
then goes off.
7. AIRBAG SENSOR ASSEMBLY
The airbag sensor assembly is mounted on the floor inside the
lower center finish panel. The airbag sensor assembly consists
of an airbag sensor, safing sensor, diagnosis circuit, ignition
control and drive circuit, etc. It receives signals from the airbag
sensor and judges whether the SRS must be activated or not.
8. FRONT AIRBAG SENSOR
The front airbag sensor is mounted inside each of the front
members. The sensor unit is a mechanical type. When the sen-
sor detects deceleration force above a predetermined limit,
contact is made in the sensor, sending a signal to the airbag
sensor assembly. The sensor cannot be disassembled.
9. SIDE AIRBAG SENSOR ASSEMBLY
The side airbag sensor assembly is mounted in the LH and RH
center pillar. The side airbag sensor assembly consists of a side
airbag sensor, safing sensor, diagnosis circuit, ignition control
and drive circuit, etc. It receives signals from the side airbag
sensors and judges whether the SRS side airbag must be acti-
vated or not.

H00998
Pretensioner (LH)Side Airbag Assembly (LH)
(Squib)Side Airbag Sensor (LH) Front Airbag Sensor (LH) Front Airbag Sensor (RH) Side Airbag Sensor (RH)Side Airbag Assembly (RH)
(Squib) Pretensioner (RH)
Airbag Sensor
AssemblyFront Passenger
Airbag Assembly
Spiral Cable
Steering Wheel
Pad (Squib)
Driver's Side J/B 12
34
5
67 8
10
119
12 13 1415
RS±4
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
2235 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
10. SRS CONNECTORS
No.ItemApplication
(1)Terminal Twin±Lock MechanismConnectors 1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15
(2)Airbag Activation Prevention MechanismConnectors 1, 2, 3, 4, 5, 7, 8, 9, 12, 13
(3)Electrical Connection Check MechanismConnectors 1, 2, 3
(4)Connector Twin±Lock MechanismConnectors 5

R12076Airbag Sensor AssemblyDisconnection
Detection
PinSRS
Warning
Light
H00955
Terminal for Diagnosis
Disconnection Detection Pin
Half Connection
Complete Connection
Terminal for
Diagnosis
RS±6
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
2237 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HINT:
The type of connector shown on the previous page is used for
the spiral cable connector º5º on the airbag sensor assembly
side.
(3) Electrical Connection Check Mechanism
This mechanism electrically checks that connectors
are connected correctly and completely. The electri-
cal connection check mechanism is designed so
that the disconnection detection pin connects with
the diagnosis terminals when the connector hous-
ing lock is locked.
HINT:
The above illustration shows connectors º1º, º2º and º3º.

AB0089
Secondary Lock
Primary LockLockLock
Primary Lock Incomplete
(Secondary Lock Prevented)Primary Lock Complete
(Secondary Lock Permitted)Twin±Lock Completed
Z14034
Fig.1
Fig.2Power Source
Safing
Sensor
Squibs
Airbag Sensor
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS±7
2238 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(4) Connector Twin±Lock Mechanism
With this mechanism connectors (male and female
connectors) are locked by 2 locking devices to in-
crease the connection reliability. If the primary lock
is incomplete, ribs interfere and prevent the sec-
ondary lock.
(b) When the vehicle is involved in a frontal collision in the
hatched area (Fig. 1) and the shock is larger than the pre-
determined level, the SRS is activated automatically. A
safing sensor is designed to go on at a smaller decelera-
tion rate than the airbag sensor. As illustrated in Fig. 2,
ignition is caused when current flows to the squib, which
happens when a safing sensor and the airbag sensor go
on simultaneously. When a deceleration force acts on the
sensors, 2 squibs in the driver airbag and front passenger
airbag ignite and generate gas. The gas discharging into
the driver airbag and front passenger airbag rapidly in-
creases the pressure inside the bags, breaking open the
steering wheel pad and instrument panel door.
Bag inflation then ends, and the bags deflate as the gas
is discharged through discharge holes at the bag's rear or
side.

H01581
Outer
H01582
Lock of connector is released
Disconnection is completed
H01583
Outer
Outer
RS±8
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
2239 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
11. DISCONNECTION OF AIRBAG SENSOR CONNEC-
TOR
(a) With holding both flank sides of the outer, slide the outer
to the direction shown by an arrow.
(b) When lock of the connectors is released disconnect the
connector.
HINT:
Make sure to hold both flank sides of the outer. If holding the top
and bottom sides, it obstructs disconnection.
12. CONNECTION OF AIRBAG SENSOR CONNECTOR
(a) Align the male connector (on the side of sensor) and fe-
male connector in the same direction as shown in the il-
lustration and fit in them without rubbing.
(b) As they are fitted in, the outer slides rearward. Press it un-
til the outer returns to its original position again.
If fitting stops on the half way, connectors will separate.
(c) Make sure to insert until the connectors are locked. After
fitting in, pull them lightly to check that they are locked.
(When locked, make sure that the outer returns to its origi-
nal position and sound at the time of fitting in can be
heard.)
HINT:
Do not fit in with holding the outer.
When fitting in, the outer slides. Do not touch it.

RS07P±01
H02615
End Pad
Finish Panel
No.1 Safety Pad
Hood Lock
Release Lever
No.1 Under CoverFront Ash Receptacle
Cluster Finish PanelGlove Compartment
Finish Plate
Glove Compartment
Panel Assembly
No.2 Under Cover
Accessary Socket Case
Accessary Socket
Console Box Carpet
Rear Console
Armrest
Console Box Register No.3 Console Box
Mounting Bracket
Console Box
No.1 Console Box Duct
Airbag Sensor Assembly
: Specified torqueN´m (kgf´cm, ft´lbf)
20 (200, 14)
RS±52
± SUPPLEMENTAL RESTRAINT SYSTEMAIRBAG SENSOR ASSEMBLY
2283 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
AIRBAG SENSOR ASSEMBLY
COMPONENTS

RS07Q±01
H02616
± SUPPLEMENTAL RESTRAINT SYSTEMAIRBAG SENSOR ASSEMBLY
RS±53
2284 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
NOTICE:
Do not open the cover or the case of the ECU and various
computers unless absolutely necessary.
(If the IC terminals are touched, the IC may be destroyed by
static electricity.)
1. REMOVE THESE PARTS:
(See page BO±91)
(a) Finish plate
(b) End Pad
(c) No.1 under cover
(d) Hood lock release lever
(e) No.1 safety pad
(f) No.2 under cover
(g) Glove compartment finish plate
(h) Glove compartment panel assembly
(i) Front ash receptacle
(j) Cluster finish panel
(k) Console box carpet
(l) Accessary socket
(m) Accessary case
(n) Lower rear console box
(o) Rear console armrest
(p) Console box register
(q) Console box
(r) No.3 console box mounting bracket
(s) No.1 console box duct
2. REMOVE AIRBAG SENSOR ASSEMBLY
(a) Disconnect the airbag sensor connectors.
NOTICE:
Remove the connectors with the sensor assembly
installed.
(b) Using a torx wrench, remove the 3 screws and airbag sen-
sor assembly.
Torx wrench: T40 (Part No.09042±00020 or locally
manufactured tool)