Mazda 6. Manual - part 369

ON-BOARD DIAGNOSTIC [AIR BAG SYSTEM] 

T–223

T

End Of Sie

2

INSPECT WIRING HARNESS BETWEEN 
PASSENGER-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–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. (Vehicle 
with curtain air bag)

• Remove B-pillar lower trim.

• 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 passenger-side side air bag 

sensor connector.

• Connect negative battery cable.

• Inspect following wiring harnesses between 

SAS unit and passenger-side side air bag 
sensor terminals for short to ground, short to 
power supply, and open circuit:
— 2B—A
— 2C—B

• Is wiring harness okay?

Yes

Replace passenger-side side air bag sensor, then go to next 
step.
(See 

T–123 SIDE AIR BAG SENSOR REMOVAL/

INSTALLATION

)

No

Replace wiring harnesses.

3

INSPECT 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 passenger-side side air bag sensor 

connector.

• Are DTCs B2445 and/or U2018 indicated?

Yes

Present malfunction diagnosis:

• Replace SAS unit.

(See 

T–124 SAS UNIT REMOVAL/INSTALLATION

)

Past malfunction diagnosis:

• Troubleshooting completed.

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

T–224

ON-BOARD DIAGNOSTIC [AIR BAG SYSTEM] 

DTC B2477

A6E817401046W22

Diagnostic procedure

End Of Sie

DTC B2773, B2774, B2775, B2776

A6E817401046W23

Diagnostic procedure

DTC B2477

SAS unit configuration error

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.

• SAS unit configuration not set correctly

POSSIBLE 

CAUSE

• SAS unit configuration error

• SAS unit malfunction

INSPECTION

ACTION

CONFIGRATION

• Configurate SAS unit, using SST (WDS or equivalent).

• Is DTC B2477 indicated?

Yes

[Present malfunction diagnosis]
Replace SAS unit.
(See 

T–124 SAS UNIT REMOVAL/INSTALLATION

)

[Past malfunction diagnosis]
Troubleshooting completed.

No

Troubleshooting completed.

DTC

B2773

Driver-side curtain air bag module system resistance low

B2774

Driver-side curtain air bag module system resistance high

B2775

Driver-side curtain air bag module system circuit short to ground

B2776

Driver-side curtain air bag module system circuit short to power supply

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 1.4—3.2 ohm) detected in driver-side curtain air bag module circuit

• Malfunction in wiring harness between driver-side curtain air bag module and SAS unit

POSSIBLE 

CAUSE

• Open or short circuit in wiring harness between driver-side curtain air bag module and SAS unit

• Driver-side curtain air bag module malfunction

• SAS unit malfunction

STEP

INSPECTION

ACTION

1

INSPECT DRIVER-SIDE CURTAIN AIR BAG 
MODULE

• Check following PID/DATA monitor, using 

SST (WDS or equivalent).
(See 

T–195 PID/DATA MONITOR TABLE

)

— DR_CURTN

• Is resistant value of driver-side curtain air 

bag module normal?
— Resistance: 1.4—3.2 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.

ON-BOARD DIAGNOSTIC [AIR BAG SYSTEM] 

T–225

T

End Of Sie

2

INSPECT DRIVER-SIDE CURTAIN AIR BAG 
MODULE 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.

• Disconnect driver-side curtain air bag 

module connector.

• Is there cracking or chipping in driver-side 

curtain air bag module connector?

Yes

Replace wiring harness.

No

Go to next step.

3

VERIFY WHETHER MALFUNCTION IS IN 
DRIVER-SIDE CURTAIN AIR BAG MODULE 
OR RELATED WIRING HARNESS

• Connect leads of SST (Fuel and 

thermometer checker) or apply 2 ohm 
resistor to driver-side curtain air bag module 
connector terminal A and B.

• Set resistance of SST (Fuel and 

thermometer checker) to 2 ohm.

• Connect negative battery cable.

• Turn ignition switch to ON position.

• Check following PID/DATA monitor, using 

SST (WDS or equivalent).
(See 

T–195 PID/DATA MONITOR TABLE

)

— DO_D_CURT

• Is related wiring harness normal?

Yes

Replace driver-side curtain air bag module.
(See 

T–122 CURTAIN AIR BAG MODULE REMOVAL/

INSTALLATION

)

No

Replace wiring harness, then go to next step.

4

INSPECT SAS UNIT

• Turn ignition switch to LOCK position.

• Disconnect negative battery cable and wait 

for more than 1 minute.

• Connect driver-side curtain air bag module 

connector.

• Are DTCs B2773, B2774, B2775 and/or 

B2776 indicated?

Yes

Present malfunction diagnosis:

• Replace SAS unit.

(See 

T–124 SAS UNIT REMOVAL/INSTALLATION

)

Past malfunction diagnosis:

• Troubleshooting completed.

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

T–226

ON-BOARD DIAGNOSTIC [AIR BAG SYSTEM] 

DTC B2777, B2778, B2779, B2780

A6E817401046W24

Diagnostic procedure

DTC

B2777

Passenger-side curtain air bag module system resistance low

B2778

Passenger-side curtain air bag module system resistance high

B2779

Passenger-side curtain air bag module system circuit short to ground

B2780

Passenger-side curtain air bag module system circuit short to power supply

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 1.4—3.2 ohm) detected in passenger-side curtain air bag module 

circuit

• Malfunction in wiring harness between passenger-side curtain air bag module and SAS unit

POSSIBLE 

CAUSE

• Open or short circuit in wiring harness between passenger-side curtain air bag module and SAS unit

• Passenger-side curtain air bag module malfunction

• SAS unit malfunction

STEP

INSPECTION

ACTION

1

INSPECT PASSENGER-SIDE CURTAIN AIR 
BAG MODULE

• Check following PID/DATA monitor, using 

SST (WDS or equivalent).
(See 

T–195 PID/DATA MONITOR TABLE

)

— PC_CURTN

• Is resistant value of passenger-side curtain 

air bag module normal?
— Resistance: 1.4—3.2 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 PASSENGER-SIDE CURTAIN AIR 
BAG MODULE 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.

• Disconnect passenger-side curtain air bag 

module connector.

• Is there cracking or chipping in passenger-

side curtain air bag module connector?

Yes

Replace wiring harness.

No

Go to next step.