1991 MAZDA MIATA Factory Service Manual

3. Reconnect negative battery cable. Measure voltage between Green/Red wire of back-up battery connector
and ground. See Fig. 8
or Fig. 9 . If voltage is zero volt, replace wire harness assembly.
4. If battery voltage is present, disconnect negative battery cable and diagnostic module Black and Gray
connectors. See Fig. 10
or Fig. 11 . Reconnect negative battery cable. Measure voltage between
White/Green wire of Gray diagnostic module connector and ground. If voltage is zero volt, replace wire
harness assembly.
5. If battery voltage is present, measure voltage between Green/Yellow wire of Gray diagnostic module
connector and ground. If voltage is zero volt, replace wire harness assembly. If battery voltage is present,
replace diagnostic module.
FUSE/RELAY LOCATION
Fuse/RelayLocation
Miata
Air Bag (15 Amps)In Fuse Block
Air Bag (10 Amps)In Main Fuse Block
Engine (15 Amps)In Fuse Block
INJ (30 Amps)In Main Fuse Block
RX7
Air Bag (15 Amps)In Fuse Block
Air Bag (30 Amps)In Main Fuse Block
Engine (30 Amps)In Main Fuse Block
Wiper (15 Amps)In Fuse Block

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
Sunday, July 05, 2009 2:11:16 PMPage 12 © 2005 Mitchell Repair Information Company, LLC.

Fig. 6: Identifying Fuses & Relays (Miata)
Courtesy of MAZDA MOTORS CORP.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
Sunday, July 05, 2009 2:11:16 PMPage 13 © 2005 Mitchell Repair Information Company, LLC.

Fig. 7: Identifying Fuses & Relays (RX7)
Courtesy of MAZDA MOTORS CORP.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
Sunday, July 05, 2009 2:11:16 PMPage 14 © 2005 Mitchell Repair Information Company, LLC.

Fig. 8: Checking Back-Up Battery Connector (Miata)
Courtesy of MAZDA MOTORS CORP.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
Sunday, July 05, 2009 2:11:16 PMPage 15 © 2005 Mitchell Repair Information Company, LLC.

Fig. 9: Checking Back-Up Battery Connector (RX7)
Courtesy of MAZDA MOTORS CORP.

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

Fig. 10: Locating Diagnostic Module Black & Gray Connectors (Miata)
Courtesy of MAZDA MOTORS CORP.

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
Sunday, July 05, 2009 2:11:16 PMPage 17 © 2005 Mitchell Repair Information Company, LLC.

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
Sunday, July 05, 2009 2:11:16 PMPage 18 © 2005 Mitchell Repair Information Company, LLC.

Fig. 12: Checking Impact Sensor Resistance
Courtesy of MAZDA MOTORS CORP.
DIAGNOSTIC TEST NO. 4
Warning Light Flashes 10 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 and go to
step 5).
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, go to next step. If resistance is not 1.2 k/ohms, replace wire harness and go to
next step.
5. If disconnected, reconnect dia
gnostic module and clockspring connectors. Reconnect negative battery

1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
Microsoft
Sunday, July 05, 2009 2:11:16 PMPage 19 © 2005 Mitchell Repair Information Company, LLC.