Acura RL (1996-2004 year). Manual - part 681

Description

SRS Airbag System - '96 - 98 Models

The SRS is a safety device which, when used in conjunction with the seat belt, is designed to help protect the driver and
front passenger in a frontal impact exceeding a certain set limit. The system consists of the SRS unit (including safing sen-

sor and impact sensor), the cable reel, the driver's airbag, and front passenger's airbag.

Seat Belt Tensioner
The seat belt tensioner is linked with the SRS airbags to further increase the effectiveness of the seat belt. In a front-end
collision, the tensioner instantly retracts the belt firmly to secure the occupants in their seats.

Operation
The main circuit in the SRS unit senses and judges the force of impact and, if necessary, ignites the inflator charges. If battery
voltage is too low or power is disconnected due to the impact, the back-up power circuit will keep voltage at a constant level.

For the SRS to operate:
(1) The impact sensor and safing sensor must activate and send electric signals to the microprocessor.
(2) The microprocessor must compute the signals and send signals to the airbag inflators and seat belt tensioners.
(3) The inflators must ignite and deploy the airbags and activate the tensioners.

Self-diagnosis System
A self-diagnosis circuit is built into the SRS unit; when the ignition switch is turned ON (II), the SRS indicator light comes
on and goes off after about 6 seconds if the system is operating normally.
If the light does not come on, or does not go off after 6 seconds, or if it comes on while driving, it indicates an abnormality
in the system. The system must be inspected and repaired as soon as possible.

For better serviceability, the memory will store the cause of the malfunction, and the data link circuit passes on the infor-
mation from the memory to the data link connector (DLC). This information can be read with the Honda PGM Tester con-
nected to the DLC (16P).

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SRS Airbag System - '99 - 01 Models

SRS Airbag
The SRS is a safety device which, when used in conjunction with the seat belt, is designed to help protect the driver and
front passenger in a frontal impact exceeding a certain set limit. The system consists of the SRS unit (including safing sen-
sor and front impact sensor), the cable reel, the driver's airbag and front passenger's airbag.

Side Airbags
Side airbags located in each front seat-back can help protect the upper torso of the driver or front seat passenger during a
moderate to severe side impact. Sensors in each door sill and in the SRS unit detect such an impact and instantly inflate

the driver's or the passenger's side airbag. Only one side airbag will deploy during a side impact. If the impact is on the

passenger's side, the passenger's side airbag will deploy even if there is no passenger.

The side airbag system also includes an Occupant Position Detection System (OPDS). This system consists of sensors and

a control unit located in the front passenger's seat-back. The control unit sends occupant height and position data to the
SRS unit. If the SRS unit determines that the front passenger's head is in the deployment path of the side airbag, it will
automatically disable the airbag. When the side airbag is disabled, the Side Airbag indicator light in the gauge assembly
alerts the driver that the passenger's side airbag will not deploy in a side impact.

Operation
The main circuit in the SRS unit senses and judges the force of impact and, if necessary, ignites the inflator charges. If bat-
tery voltage is too low or power is disconnected due to the impact, the voltage regulator and the back-up power circuit

respectively will keep voltage at a constant level.

For the SRS to operate:

Airbag and Seat Belt Tensioner

(1) The frontal impact sensor must activate, and send electric signals to the microprocessor.

(2) The microprocessor must compute the signals, and depending on the severity of the collision and whether the seat

belt buckle switch is ON or OFF, it sends the appropriate signals to the airbag inflators and seat belt tensioners.

(3) The inflators that received signals must ignite and deploy the units.

Side Airbag
(1) The side impact sensors must activate, and send electric signals to the microprocessor.

(2) The microprocessor must compute the signals and send them to the side airbag inflators. However the microproces-

sor cuts off the signals to the front passenger's side airbag if the SRS unit determines that the front passenger's head
is in the deployment path of the side airbag.

(3) The inflator that received the signal must ignite and deploy the side airbag.

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Description

SRS Airbag System - '99 - 01 Models (cont'd)

If the light does not come on, or does not go off after 6 seconds, or if it comes on while driving, it indicates an abnormality
in the system. The system must be inspected and repaired as soon as possible.

For better serviceability, the SRS unit memory stores the cause of the malfunction, and the unit is connected to the data
link connector (DLC). This information can be read with the Honda PGM Tester when it is connected to the DLC (16P).

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Precautions/Procedures

General Precautions

• Carefully inspect any SRS part before you install it. Do

not install any part that shows signs of being dropped
or improperly handled, such as dents, cracks or defor-
mation:

Airbags (frontal airbags and side airbags)
Cable reel
SRS unit

Seat belt tensioners

• Use only a digital multimeter to check the system. If

it's not a Honda multimeter, make sure its output is
10 mA (0.01 A) or less when switched to the smallest

value in the ohmmeter range. A tester with a higher
output could damage the airbag circuit or cause acci-
dental deployment and possible injury.

• Do not install used SRS parts from another vehicle.

When making SRS repairs, use only new parts.

• Except when performing electrical inspections,

always disconnect both the negative cable and posi-

tive cable from the battery, and wait at least 3 min-

utes before beginning work.

• Replacement of the combination light and wiper/

washer switches and cruise control switch can be
done without removing the steering wheel:

For combination light and wiper/washer switch
replacement, see

section 23

For cruise control set/resume/cancel switch
replacement, see

section 4

• Whenever the ignition switch is ON (II), or has been

turned OFF for less than 3 minutes, be careful not to

bump the SRS unit; the airbags could accidentally

deploy and cause damage or injury.

• Whenever the airbags have been activated, replace

the seat belt tensioners and the SRS unit.

• The original radio has a coded theft protection circuit.

Be sure to get the customer's code number before dis-

connecting the battery cables.

• The PCM memory must be reset after reconnecting the

battery (see page

11-125

Airbag Handling and Storage

Do not try to disassemble any of the airbags, frontal or
side. They have no serviceable parts. Once an airbag
has been operated (deployed), it cannot be repaired or
reused.

For temporary storage of an airbag during service,
please observe the following precautions:

• Store a removed airbag with the pad surface up and a

removed side airbag with the caution label surface up.

All airbag connectors have a built-in short contact (see
page

24-30

If an airbag is improperly stored face down,

accidental deployment could propel the unit with enough
force to cause serious injury.

AIRBAG CONNECTORS
(With built-in short contact)

• Store a removed airbag on a secure flat surface

away from any high heat source (exceeding
200°F/93°C) and free of any oil, grease, detergent or

water.

CAUTION: Improper handling or storage can internally
damage an airbag, making it inoperative.

K you suspect an airbag has been damaged, install a new
unit, and refer to the Deployment/Disposal Procedures for
disposing of the damaged airbag.

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