Lexus RX300 (MCU15). Service manual - part 524

R12076

Airbag Sensor Assembly

Disconnection

Detection

Pin

SRS

Warning

Light

H01315

Terminal for Diagnosis

Disconnection Detection Pin

FHalf Connection

FComplete Connection

Terminal for
Diagnosis

RS–6

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

LEXUS RX300   (RM785E)

HINT:
The type of connector is shown in the diagram on the previous
page.

(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 illustration shows connectors ”1”, ”2” and ”3” in step 11.

Z14034

Fig.1

Fig.2

Power Source

Safing

Sensor

Squibs

Deceleration Sensor

H01581

Outer

H01582

Lock of connector is released

Disconnection is completed

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

RS–7

LEXUS RX300   (RM785E)

(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 deceleration sen-
sor go on simultaneously. When a deceleration force acts
on the sensors, 2 squibs in the driver airbag and front pas-
senger airbag ignite and generate gas. The gas discharg-
ing into the driver airbag and front passenger airbag rap-
idly increases the pressure inside the bags, breaking
open the steering wheel pad and instrument panel.
Bag inflation then ends, and the bags deflate as the gas
is discharged through discharge holes at the bag’s rear or
side.

11.

DISCONNECTION OF CONNECTORS FOR FRONT
AIRBAG SENSOR AND SIDE AIRBAG SENSOR

(a)

While holding both flank sides of the outer, slide the outer
to the direction shown by an arrow.

(b)

Lock of the connectors is released, then disconnect the
connectors.

HINT:
Be sure to hold both flank sides of the outer. If holding the top
and bottom sides, it will obstruct disconnection.

H01583

Outer

Outer

RS–8

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

LEXUS RX300   (RM785E)

12.

CONNECTION OF CONNECTORS FOR FRONT AIR-
BAG SENSOR AND SIDE AIRBAG SENSOR

(a)

Align the male connector (of 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 half way, connectors will separate.
(c)

Be sure to insert until they are locked. After fitting in, pull
them slightly to check that they are locked. (When locked,
make sure that the outer returns to its original position and
sound at the time of fitting in can be heard.)

HINT:

S

Do not fit in while holding the outer.

S

When fitting in, the outer slides. Do not touch it.

H01584

Slider

Disconnection is completed

Slider

H01585

Slider

Slider

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

RS–9

LEXUS RX300   (RM785E)

13.

DISCONNECTION OF SIDE AIRBAG CONNECTOR

(a)

Place a finger on the slider.

(b)

Slide the slider to release lock.

(c)

Disconnect the connector.

14.

CONNECTION OF SIDE AIRBAG CONNECTOR