1991 MAZDA MIATA Factory Service Manual

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
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ACTIVATING AIR BAG SYSTEM. Check AIR BAG indicator light to ensure system is functioning properly.
See SYSTEM OPERATION CHECK.
AIR BAG MODULE
Removal & Installation
1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM.
2. Air bag module is located on center of steering wheel. See Fig. 4
or Fig. 5 . Remove air bag module nuts
and remove module from steering wheel. To install, reverse removal procedure. Tighten air bag module
mounting nuts 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.
Fig. 4: Identifying Air Bag System Components (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. 5: Identifying Air Bag System Components (RX7 Convertible)
Courtesy of MAZDA MOTORS CORP.
STEERING WHEEL
Removal & Installation
Remove air bag module. See AIR BAG MODULE. Remove steering wheel nut. DO NOT strike steering shaft
with a hammer, or steering shaft may collapse. Remove steering wheel with steering wheel puller. To install,
reverse removal procedure. Tighten steering wheel nut to specification. See TORQUE SPECIFICATIONS
table.
CLOCKSPRING CONNECTOR ASSEMBLY
Installation
1. To install, reverse removal procedure. Before installing steering wheel, center clockspring. See
CLOCKSPRING CENTERING under ADJUSTMENTS. Tighten steering wheel nut to specification. See
TORQUE SPECIFICATIONS table.
2. After installing clockspring connector and combination switch assembly, reactivate air bag system. See
DISABLING & ACTIVATING AIR BAG SYSTEM. Check AIR BAG indicator light to ensure system is
functionin
g properly. See SYSTEM OPERATION CHECK.
NOTE: Clockspring connector assembly is part of the combination switch. When
replacing clockspring, replace clockspring and combination switch as an
assembly.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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Removal
1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM.
2. Clockspring connector assembly is located under steering wheel, in steering column. See Fig. 4
or Fig. 5.
Remove air bag module. See AIR BAG MODULE. Remove steering wheel nut and remove steering
wheel with steering wheel puller. Remove column covers. Remove screws. Remove clockspring
connector and combination switch as an assembly.
DIAGNOSTIC MODULE & BACK-UP BATTERY
Removal & Installation
1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM.
2. Diagnostic module and back-up battery is located under left side of instrument panel. See Fig. 4
or Fig.
5 . Disconnect diagnostic module and back-up battery connectors. Remove nuts. Remove diagnostic
module and back-up battery as an assembly. To install, reverse removal procedure. After diagnostic
module and back-up battery are installed, 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.
SYSTEM OPERATION CHECK
Turn ignition switch to the ON or START position. AIR BAG warning light in instrument cluster should
illuminate for approximately 6 seconds then go out. This indicates that the air bag system is functioning
properly. If any of the following conditions exists, air bag system is malfunctioning and needs repair.
AIR BAG warning light does not illuminate as described.
AIR BAG warning light stays on for more than 6 seconds.
AIR BAG warning light illuminates while driving.
If air bag system components are replaced for any reason, air bag system must be checked for proper function
after repair. Turn ignition on. AIR BAG warning light should illuminate for approximately 6 seconds then go
out. If AIR BAG warning light does not illuminate as described, air bag system is malfunctioning and needs
repair. If warning light functions as described, check horn operation. If horn does not sound, remove air bag
module and check air bag module and horn switch connections. Always follow service precautions and
deactivate air bag system before performing repairs. See DISABLING & ACTIVATING AIR BAG
SYSTEM .
WIRE REPAIR
DO NOT repair air bag system wiring. If air bag harness connectors are faulty, replace faulty wiring harness.
TORQUE SPECIFICATIONS

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