1991 MAZDA MIATA Factory Service Manual

AIR BAG RESTRAINT SYSTEM
MAZDA 1990-91 AIR BAGS
DESCRIPTION & OPERATION
The air bag restraint system, when used in conjunction with seat belt, provides increased protection for the
driver in a collision. The air bag restraint system consists of the following: AIR BAG warning light, air bag
module, clockspring connector, diagnostic module, crash sensors, back-up battery, and wiring harnesses.
The air bag is designed to deploy when rear safing sensor and at least one front impact sensor close in a
collision, and ignition switch is in the ON position. The back-up battery supplies current for the ignitor if the
vehicle battery or fuses fail during a collision. The diagnostic module monitors the air bag system for failures. I
f
any failures are detected by the module, the driver is warned of such failure(s) through the activation or flashing
of the AIR BAG warning light.
SERVICE PRECAUTIONS
Disable air bag system before servicing any air bag system or steering column component. See
DISABLING & ACTIVATING AIR BAG
SYSTEM
Wait about 10 MINUTES after disabling air bag system before servicing. Air bag system voltage is
maintained for about 10 MINUTES after system is disabled. Failure to wait 10 MINUTES before
servicing system may cause accidental air bag deployment and possible personal injury.
On Miata, obtain radio code number from customer and deactivate radio anti-theft function before
disconnecting battery.
Because of the critical system operating requirements, DO NOT service any air bag system component.
Corrections are made by replacement only.
DO NOT use an ohmmeter to check resistance of air bag module, as it may cause air bag deployment.
When carrying a live (undeployed) module, ensure trim cover is pointed away from your body. This
minimizes chance of injure in the event ofaccidental air bag deployment.
When placing a live air bag module on any surface, always face trim cover upward to reduce motion of
module if it is accidentally deployed.
If an open circuit is present, replace entire wiring harness. DO NOT attempt wire repair.
Impact sensors must always be installed with arrow marks facing front of vehicle. Also, check sensors for
cracks, defects or rust before installation. Replace impact sensor(s) if required.
Air bag system clockspring MUST be aligned in the neutral position, since its rotation ability is limited.
DO NOT turn steerin
g wheel or column after removal of steering gear. WARNING:To avoid injury from accidental air bag deployment, read and carefully
follow all WARNINGS and SERVICE PRECAUTIONS.
NOTE: The following precautions should be observed when working with air bag
systems.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
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Microsoft
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A double-lock mechanism is used on clockspring connectors. DO NOT use excessive force when
disconnecting connectors, as damage to connector may occur.
DISABLING & ACTIVATING AIR BAG SYSTEM
AIR BAG SYSTEM
DISABLING SYSTEM
On Miata, obtain radio code number from customer, and deactivate audio anti-theft function. On all models,
turn ignition switch off. Disconnect and shield negative battery cable. Remove knee protector. Disconnect
Orange and Blue clockspring connectors at base of steering column. See Fig. 1
.
ACTIVATING SYSTEM
Reconnect battery and clockspring connectors. Turn ignition switch to RUN position. Check AIR BAG
indicator li
ght to ensure system is operating properly. See SYSTEM OPERATION CHECK. WARNING:Wait about 10 MINUTES after disabling air bag system before servicing.
Air bag system voltage is maintained for about 10 MINUTES after system
is disabled. Failure to wait 10 MINUTES before servicing system may
cause accidental air bag deployment and possible personal injury.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
Sunday, July 05, 2009 2:11:16 PMPage 2 © 2005 Mitchell Repair Information Company, LLC.

Fig. 1: Locating Clockspring Connector
Courtesy of MAZDA MOTORS CORP.
POST-COLLISION AIR BAG SAFETY INSPECTION
POST-COLLISION AIR BAG SAFETY INSPECTION
Replace After DeploymentAir Bag Module(s)
Clockspring
Inspect & If Damaged, Replace Component (Even
If Air Bag Did Not Deploy)Air Bag Diagnosis Control Unit
Impact Sensors & Sensors Mountings
Steering Column
Steering Wheel
Wiring Harness
CommentsDO NOTattempt wiring harness repairs.
Replace entire wiring harness.
Impact sensors must always be installed with
arrow on sensor facing front of vehicle.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
Sunday, July 05, 2009 2:11:16 PMPage 3 © 2005 Mitchell Repair Information Company, LLC.