1991 MAZDA MIATA sensor

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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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
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ADJUSTMENTS
CLOCKSPRING CENTERING
Set front wheels in straight-ahead position. Turn clockspring connector clockwise until it stops (do not force).
Return connector 2 3/4 turns counterclockwise. Rotate clockspring connector further, if necessary, to align
marks on connector and outer housing.
DISPOSAL PROCEDURES
DEPLOYED AIR BAG
Dispose deployed air bag module as you would any other part. Wear gloves and safety glasses when handling
air bag module.
SCRAPPED VEHICLE
1. Ensure vehicle is outside, and away from other vehicles and people. Open convertible top and doors.
Disconnect negative battery cable.
2. Ensure air bag module is firmly mounted to steering wheel. Remove knee protector and disconnect
Orange and Blue clockspring connectors at base of steering column. See Fig. 1
. Cut clockspring
connector Blue wires.
3. Connect 2 jumper wires (20 feet long) to cut clockspring wires. Connect other ends of wires to a 12-volt
battery to deploy air bag. Because of heat, wait 10 MINUTES before touching deployed air bag.
REMOVAL & INSTALLATION
CRASH SENSORS NOTE: Perform the following procedures when scrapping a vehicle with undeployed air
bag.
WARNING:Follow air bag service precautions to prevent accidentalair bag
deployment and personal injury. See SERVICE PRECAUTIONS.
NOTE: After component replacement, check system to ensure proper operation. See
SYSTEM OPERATION CHECK.
NOTE: Crash sensor orientation and mounting is important for proper operation. All
sensors must be positioned so that arrow points forward. If there is sheet metal
damage near sensor mounting point, inspect body structure at sensor
mounting point for deformation. If damaged, restore to original shape. Ensure
sensor mounting bolts or nuts are tightened to specification. See TORQUE
SPECIFICATIONS table.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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Removal (Front Impact Sensors)
1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM.
2. Front impact sensors are located in left front and right front of vehicle. See Fig. 2
or Fig. 3 . To remove
left or right sensor, remove wheelwell undercover, and disconnect connector(s). Remove retaining clips
and bolts. Remove sensor(s).
Fig. 2: Locating Crash Sensors (Miata)

Courtesy of MAZDA MOTORS CORP.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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Fig. 3: Locating Crash Sensors (RX7 Convertible)
Courtesy of MAZDA MOTORS CORP.
Installation
To install, reverse removal procedure. Position sensor with arrow toward front of vehicle. Tighten mounting
bolts to specification. See TORQUE SPECIFICATIONS table. Reactivate air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM. Check AIR BAG indicator light to ensure system is functioning properly.
See SYSTEM OPERATION CHECK.
Removal (Rear Safing Sensor)
Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag system.
See DISABLING & ACTIVATING AIR BAG SYSTEM. Rear safing sensor is located under center of
instrument panel. Remove instrument panel. Locate and disconnect safing sensor connectors. See Fig. 2
or Fig.
3 . Remove sensor and cover.
Installation
To install, reverse removal procedure. Position sensor with arrow toward front of vehicle. Tighten mounting
nuts to specification. See TORQUE SPECIFICATIONS table. Reactivate air ba
g system. See DISABLING &
CAUTION: A double-lock mechanism is used on clockspring connectors. DO NOT
use excessive force when disconnecting connectors, as damage to
connector may occur.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
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TORQUE SPECIFICATIONS
DIAGNOSIS & TESTING
SELF-DIAGNOSTIC SYSTEM
Trouble Shooting
AIR BAG warning light flashes are used to diagnose air bag system. The number of warning light flashes
depends on the type of fault being detected. Codes are prioritized so that if 2 or more faults are present, the
highest test-priority fault indication will remain until corrected.
Warning Light Does Not Illuminate
Check for blown fuses, burned-out bulb, disconnected diagnostic module, or open circuit between warning light
and diagnostic module.
Warning Light Flashes Or Remains On
Check code output of AIR BAG warning light. See AIR BAG FLASH CODES table.
AIR BAG FLASH CODES
ApplicationFt. Lbs. (N.m)
Air Bag Module Nuts12-15 (16-20)
Steering Wheel Nut29-36 (39-49)
INCH Lbs. (N.m)
Front Impact Sensor Bolts78-113 (9-13)
Rear Safing Sensor Nuts
Miata78-113 (9-13)
RX761-87 (7-10)
WARNING:Follow air bag service precautions to prevent accidentalair bag
deployment and personal injury. See SERVICE PRECAUTIONS.
NOTE: After component replacement, check system to ensure proper operation. See
SYSTEM OPERATION CHECK.
PriorityFlash CodeCause/Diagnosis
1Remains OnFaulty Diagnostic Module
Poor Connection Of Diagnostic
Module Connector (See
DIAGNOSTIC TEST NO. 1)
2Flashes 3 TimesOpen Circuit
Poor Connection Of Power Source

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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DIAGNOSTIC TEST NO. 1
Warning Light Remains On
Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Ensure diagnostic module
connectors are properly connected. If connector is okay, replace diagnostic module.
DIAGNOSTIC TEST NO. 2
Warning Light Flashes 3 Times
1. Measure battery voltage. If voltage is less than 9 volts, charge battery. If battery voltage is okay, check
fuses/relays in order given in FUSE/RELAY LOCATION table. See Fig. 6
or Fig. 7 .
2. If fuses and relays are okay, disable air bag system. See DISABLING & ACTIVATING AIR BAG
SYSTEM. Ensure back-up battery connector is properly connected. If connection is okay, disconnect
back-up battery connector.
Circuit (See DIAGNOSTIC TEST
NO. 2)
3Flashes 5 TimesFaulty Front Impact Sensor (See
DIAGNOSTIC TEST NO. 3)
4Flashes 10 TimesFaulty Diagnostic Module (System
Down-Fused Burned) (See
DIAGNOSTIC TEST NO. 4)
5Flashes 4 TimesFaulty Rear safing Sensor (See
DIAGNOSTIC TEST NO. 5)
6Flashes 6 TimesFaulty Air Bag Module
Poor Connection Of Clockspring
Connector (See DIAGNOSTIC
TEST NO. 6)
7 (1) Flashes 7 TimesPoor Wiring Harness Ground (See
DIAGNOSTIC TEST NO. 8)
8Flashes 8 TimesPoor Ground Of Front Impact
Sensor (See DIAGNOSTIC TEST
NO. 8)
9Flashes 9 TimesOpen Circuit Between Diagnostic
Module and Front Impact Sensor
(See DIAGNOSTIC TEST NO. 3)
10Flashes 2 TimesPoor Ground Of All Front Impact
Sensors (See DIAGNOSTIC TSET
NO. 7)
(1)Code 7 Does not apply to 1990 Miata

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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Fig. 11: Locating Diagnostic Module Black & Gray Connectors (RX7)
Courtesy of MAZDA MOTORS CORP.
DIAGNOSTIC TEST NO. 3
Warning Light Flashes 5 Or 9 Times
1. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Disconnect front
impact sensor connectors (center, left, and right), and measure resistance of each sensor. See Fig. 12
.
Resistance should be approximately 1.2 k/ohms. If resistance is not as specified, replace sensor.
2. If resistance is about 1.2 k/ohms, reconnect all front impact sensor connectors. Disconnect diagnostic
module Black and Gray connectors. See Fig. 10
or Fig. 11 . Measure resistance between diagnostic
module Gray connector Brown/Green wire and ground. If resistance is 1.2 k/ohms, go to next step. If
resistance is not 1.2 k/ohms, replace wire harness.
3. Measure resistance between diagnostic module Gray connector Brown/Red wire and ground. If resistance
is 1.2 k/ohms, go to next step. If resistance is not 1.2 k/ohms, replace wire harness.
4. Measure resistance between diagnostic module Black connector Brown/Black wire and ground. If
resistance is 1.2 k/ohms, replace dia
gnostic module. If resistance is not 1.2 k/ohms, replace wire harness.

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