Mazda 626 Station Wagon, Workshop Manual

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ON-BOARD DIAGNOSTIC
Diagnostic procedure
STEP INSPECTION ACTION
1
• Is vehicle equipped with side air bag? Yes Go to next step.
No Go to Step 6.
2 INSPECT WIRING HARNESS BETWEEN
DRIVER-SIDE SIDE AIR BAG SENSOR
AND SAS UNIT
Warning
• Handling air bag system components
improperly can accidentally deploy
air bag modules and pre-tensioner
seat belts, which may seriously injure
you. Read AIR BAG SYSTEM
SERVICE WARNINGS before handling
air bag system components. See
T-56 SERVICE WARNINGS
Yes Present malfunction diagnosis:
• Go to next step.
Past malfunction diagnosis:
• Replace driver-side side air bag sensor.
(See T-58 SIDE AIR BAG SENSOR
REMOVAL/INSTALLATION)
• Turn ignition switch to LOCK position.
• Disconnect negative battery cable and wait
for more than 1 minute.
• Remove clock spring.
(See Section T)
• Remove glove compartment.
• Disconnect passenger-side air bag module
connector.
• Disconnect driver and passenger-side side
air bag module connectors.
• Remove B-pillar lower trims.
• Disconnect driver and passenger-side pre-
tensioner seat belt connectors.
• Remove side walls.
• Disconnect all SAS unit connectors.
• Disconnect driver-side side air bag sensor
connector.
• Inspect following wiring harness between
SAS unit and driver-side side air bag
sensor terminals (harness side) for short to
ground, short to power supply, and open
circuit:
— 1B and A
— 1D and B
— 1F and C
— 1E and D
• Are wiring harnesses okay?
No
Replace wiring harnesses.
3 INSPECT GROUND CIRCUIT IN SAS UNIT Yes Go to next step.
• Is there continuity between SAS unit
terminals 1F and 2Q?
No Replace SAS unit.
(See T-59 SAS UNIT REMOVAL/INSTALLATION)
4
INSPECT POWER SUPPLY CIRCUIT OF
DRIVER-SIDE SIDE AIR BAG SENSOR
• Connect all SAS unit connectors.
• Connect clock spring connector.
• Connect passenger-side air bag module
connector.
• Connect driver and passenger-side side air
bag module connectors.
• Connect driver and passenger-side pre-
tensioner seat belt connectors.
• Connect negative battery cable.
• Turn ignition switch to ON position.
• Measure voltage at driver-side side air bag
sensor connector terminal A.
• Is voltage approximately 5 V?
Yes Replace driver-side side air bag sensor, then go to next
step.
(See T-58 SIDE AIR BAG SENSOR
REMOVAL/INSTALLATION)
No
Replace SAS unit.
(See T-59 SAS UNIT REMOVAL/INSTALLATION)
T -7 8