Mazda 6. Manual — part 363

ON-BOARD DIAGNOSTIC [AIR BAG SYSTEM]

T–199

T

Diagnostic procedure

STEP

INSPECTION

ACTION

1

INSPECT METER IG 15 A FUSE

• Turn ignition switch to LOCK position.

• Disconnect negative battery cable.

• Remove METER IG 15 A fuse.

• Is fuse okay?

Yes

Reinstall METER IG 15 A fuse, then go to next step.

No

Replace METER IG 15 A fuse.

2

INSPECT FOR CONTINUITY BETWEEN
METER IG 15 A FUSE AND INSTRUMENT
CLUSTER

• Connect negative battery cable.

• Turn ignition switch to ON position.

• Measure voltage at instrument cluster

connector terminal 2V.

• Is voltage more than 9 V?

Yes

Go to next step.

No

Repair wiring harness.

3

INSPECT WIRING HARNESS BETWEEN
INSTRUMENT CLUSTER 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–117 SERVICE WARNINGS

)

• Turn ignition switch to LOCK position.

• Disconnect negative battery cable and wait

for more than 1 minute.

• Remove column cover.

• Disconnect clock spring connector.

• Remove glove compartment.

• Disconnect passenger-side air bag module

connector.

• Disconnect driver and passenger-side

curtain air bag module connectors. (Vehicles
with curtain air bag)

• Disconnect driver and passenger-side side

air bag module connectors. (Vehicles with
side air bag)

• Remove B-pillar lower trims. (Vehicle with

pre-tensioner seat belt)

• Disconnect driver and passenger-side pre-

tensioner seat belt connectors. (Vehicle with
pre-tensioner seat belt)

• Turn up floor covering.

• Disconnect all SAS unit connectors.

• Disconnect instrument cluster.

• Inspect following wiring harness between

SAS unit and instrument cluster terminals for
short to ground, short to power supply, and
open circuit:
— 1T—1O

• Is wiring harness okay?

Yes

Go to next step.

No

Replace wiring harness.

4

INSPECT AIR BAG SYSTEM WARNING
LIGHT

• Connect instrument cluster.

• Turn ignition switch to ON position.

• Is air bag system warning light illuminated?

Yes

Go to next step.

No

Replace instrument cluster.
(See

T–72 INSTRUMENT CLUSTER REMOVAL/

INSTALLATION

)

5

INSPECT AIR BAG SYSTEM WARNING
LIGHT

• Using a jumper wire, cause a short circuit

between instrument cluster terminal 1O and
ground.

• Does air bag system warning light go out?

Yes

[Present malfunction diagnosis]
Replace SAS unit.
(See

T–124 SAS UNIT REMOVAL/INSTALLATION

)

[Past malfunction diagnosis]
Troubleshooting completed.

No

Replace instrument cluster.
(See

T–72 INSTRUMENT CLUSTER REMOVAL/

INSTALLATION

)

T–200

ON-BOARD DIAGNOSTIC [AIR BAG SYSTEM]

End Of Sie

DTC B1871

A6E817401046W08

Diagnostic procedure

DTC B1871

Occupancy sensor system (communication error, sensor internal circuit abnomal)

DETECTION

CONDITION

Warning
• Detection conditions are for understanding DTC outline before performing inspection.

Performing inspection with only detection conditions may cause injury due to operating error
or damage the system. When performing inspection, always follow inspection procedure.

• Malfunction in wiring harness between SAS unit and occupancy sensor

• Malfunction in occupancy sensor circuit

POSSIBLE

CAUSE

• Open or short circuit in wiring harness between METER IG 15 A fuse and occupancy sensor

• Open or short circuit in wiring harness between SAS unit and occupancy sensor

• Open circuit in wiring harness between occupancy sensor and ground

• Occupancy sensor malfunction

• SAS unit malfunction

STEP

INSPECTION

ACTION

1

• Is vehicle equipped with passenger-side air bag

cut-off function?

Yes

Go to next step.

No

[Present malfunction diagnosis]
Replace SAS unit.
(See

T–124 SAS UNIT REMOVAL/INSTALLATION

)

[Past malfunction diagnosis]
Troubleshooting completed.

ON-BOARD DIAGNOSTIC [AIR BAG SYSTEM]

T–201

T

End Of Sie

2

INSPECT WIRING HARNESS BETWEEN
OCCUPANCY 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–117 SERVICE WARNINGS

)

• Turn ignition switch to LOCK position.

• Disconnect negative battery cable and wait for

more than 1 minute.

• Remove column cover.

• Disconnect clock spring connector.

• Remove glove compartment.

• Disconnect passenger-side air bag module

connector.

• Disconnect driver and passenger-side side air

bag module connectors. (Vehicle with side air
bag)

• Disconnect driver and passenger-side curtain air

bag module connectors. (Vehicles with curtain
air bag)

• Remove B-pillar lower trim. (Vehicle with pre-

tensioner seat belt)

• Disconnect drive- and passenger-side pre-

tensioner seat belt connectors. (Vehicle with
pre-tensioner seat belt)

• Turn up floor covering.

• Disconnect all SAS unit connectors.

• Disconnect occupancy sensor connector.

• Connect negative battery cable.

• Inspect following wiring harness between SAS

unit and occupancy sensor terminals for short to
ground, short to power supply, and open circuit:
— 1I—B

• Is wiring harness okay?

Yes

Go to next step.

No

Replace wiring harness.

3

INSPECT WIRING HARNESS BETWEEN METER
IG 15 A FUSE AND OCCUPANCY SENSOR

• Connect negative battery cable.

• Turn ignition switch to ON position.

• Measure voltage at occupancy connector

terminal A.

• Is voltage more than 9V?

Yes

[Present malfunction diagnosis]Go to next step.
[Past malfunction diagnosis]
Troubleshooting completed.

No

Replace wiring harness.

4

VERIFY WHETHER MALFUNCTION IS IN
OCCUPANCY SENSOR OR SAS UNIT

• Turn ignition switch to LOCK position.

• Disconnect negative battery cable and wait for

more than 1 minute.

• Connect all SAS unit connectors.

• Connect drive- and passenger-side pre-

tensioner seat belt connectors. (Vehicle with
pre-tensioner seat belt)

• Connect driver and passenger-side curtain air

bag module connectors. (Vehicles with curtain
air bag)

• Connect driver and passenger-side side air bag

module connectors. (Vehicle with side air bag)

• Connect passenger-side air bag module

connector.

• Connect clock spring connector.

• Connect occupancy sensor connector.

• Short occupancy sensor connector terminal B to

ground.

• Connect negative battery cable.

• Turn ignition switch to ON position.

• Is DTC B1871 indicated?

Yes

Replace SAS unit.
(See

T–124 SAS UNIT REMOVAL/INSTALLATION

)

No

Replace seat cushion.
(See

S–106 FRONT SEAT DISASSEMBLY/ASSEMBLY

)

STEP

INSPECTION

ACTION

T–202

ON-BOARD DIAGNOSTIC [AIR BAG SYSTEM]

DTC B1877, B1878, B1879, B1885

A6E817401046W09

Diagnostic procedure

DTC

B1877

Driver-side pre-tensioner seat belt system resistance high

B1878

Driver-side pre-tensioner seat belt system circuit short to power supply

B1879

Driver-side pre-tensioner seat belt system circuit short to ground

B1885

Driver-side pre-tensioner seat belt system resistance low

DETECTION

CONDITION

Warning
• Detection conditions are for understanding DTC outline before performing inspection.

Performing inspection with only detection conditions may cause injury due to operating error
or damage the system. When performing inspection, always follow inspection procedure.

• Abnormal resistance (other than 1.5—3.1 ohm) detected in driver-side pre-tensioner seat belt circuit

• Malfunction in wiring harness between driver-side pre-tensioner seat belt and SAS unit

POSSIBLE

CAUSE

• Open or short circuit in wiring harness between driver-side pre-tensioner seat belt and SAS unit

• Driver-side pre-tensioner seat belt malfunction

• SAS unit malfunction

STEP

INSPECTION

ACTION

1

INSPECT DRIVER-SIDE PRE-TENSIONER
SEAT BELT

• Check following PID/DATA monitor, using

SST (WDS or equivalent).
(See

T–195 PID/DATA MONITOR TABLE

)

— DR_PTENS

• Is resistant value of driver-side pre-tensioner

seat belt normal?
— Resistance: 1.5—3.1 ohm

Yes

Present malfunction diagnosis:

• Replace SAS unit.

(See

T–124 SAS UNIT REMOVAL/INSTALLATION

)

Past malfunction diagnosis:

• Troubleshooting completed.

No

Go to next step.

2

INSPECT DRIVER-SIDE PRE-TENSIONER
SEAT BELT CONNECTOR

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–117 SERVICE WARNINGS

)

• Turn ignition switch to LOCK position.

• Disconnect negative battery cable and wait

for more than 1 minute.

• Remove driver’s side B-pillar lower trim.

• Disconnect driver-side pre-tensioner seat

belt connector.

• Is there cracking or chipping in driver-side

pre-tensioner seat belt connector?

Yes

Replace wiring harness.

No

Go to next step.