Subaru Legacy (2005 year). Service manual - part 922

SB-9

SEAT BELT SYSTEM

Inspection Locations After a Collision

3. Inspection Locations After a 

Collision

A: INSPECTION

Check for the following, and replace with new parts
if necessary.
• Center pillar lower garnish is discolored or
cracked.
• Wire harness and connector are damaged.

SB-10

SEAT BELT SYSTEM

Seat Belt Warning System

4. Seat Belt Warning System

A: WIRING DIAGRAM

1. LHD MODEL

<Ref. to WI-240, LHD MODEL, WIRING DIAGRAM, Seat Belt Warning System.>

2. RHD MODEL

<Ref. to WI-241, RHD MODEL, WIRING DIAGRAM, Seat Belt Warning System.>

B: INSPECTION

TROUBLE SYMPTOM:
• Seat belt warning light does not come on or go off.
• Warning buzzer does not beep.

1. DRIVER’S SEAT

Step

Check

Yes

No

1

CHECK BODY INTEGRATED MODULE.
Check DTC of body integrated module using 
Subaru Select Monitor. <Ref. to LAN(diag)-14, 
OPERATION, Subaru Select Monitor.>

Is DTC displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 2.

2

CHECK VEHICLE SPEED SIGNAL.
Check DTC of ABS or vehicle dynamics control 
(VDC) using Subaru Select Monitor. <Ref. to 
ABS(diag)-15, OPERATION, Subaru Select 
Monitor.> or <Ref. to VDC(diag)-16, OPERA-
TION, Subaru Select Monitor.> 

Is DTC displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 3.

3

CHECK BODY INTEGRATED MODULE.
1) Connect the Subaru Select Monitor to data 
link connector.
2) Turn the ignition switch to ON (engine 
OFF).
3) Turn the Subaru Select Monitor power 
switch to ON.
4) Read the data of “Driver’s Seat SW input” 
using Subaru Select Monitor. <Ref. to 
LAN(diag)-14, OPERATION, Subaru Select 
Monitor.>

Is the data of “Driver’s Seat 
SW input” “OFF”?

Go to step 4.

Check the harness 
between body inte-
grated module and 
chassis ground.

4

CHECK SEAT BELT WARNING LIGHT.
Read the data of “D-belt warning light O/P” 
using Subaru Select Monitor. <Ref. to 
LAN(diag)-14, OPERATION, Subaru Select 
Monitor.>

Is the data of “D-belt warning 
light O/P” “ON”? Or does the 
seat belt warning light on com-
bination meter illuminate?

Go to step 5.

Check the harness 
between ignition 
switch and body 
integrated module.

5

CHECK BODY INTEGRATED MODULE.
1) Insert the tongue plate to driver’s seat belt 
buckle.
2) Read the data of “Driver’s Seat SW input” 
using Subaru Select Monitor. <Ref. to 
LAN(diag)-14, OPERATION, Subaru Select 
Monitor.>

Is the data of “Driver’s Seat 
SW input” “ON”?

Go to step 6.

Check the body 
integrated module.

6

CHECK SEAT BELT WARNING LIGHT.
Read the data of “D-belt warning light O/P” 
using Subaru Select Monitor. <Ref. to 
LAN(diag)-14, OPERATION, Subaru Select 
Monitor.>

Is the data of “D-belt warning 
light O/P” “OFF”? Or is the seat 
belt warning light on combina-
tion meter off?

Go to step 7.

Check the harness 
between ignition 
switch and body 
integrated module.

SB-11

SEAT BELT SYSTEM

Seat Belt Warning System

7

CHECK VEHICLE MODEL.

Is the vehicle EC, EK or KA 
model?

Go to step 8.

The seat belt 
warning light sys-
tem is normal at 
this time.
A temporary poor 
contact of har-
ness connector 
may be the cause. 
Check the poor 
contact.

8

CHECK SEAT BELT WARNING SYSTEM.
1) Hold the tang plate disconnected from seat 
belt buckle.
2) Turn the ignition switch to ON.

Does the seat belt warning 
light illuminate?

Go to step 9.

Replace the body 
integrated module.

9

CHECK SEAT BELT WARNING SYSTEM.
1) Lift-up the vehicle.

NOTE:

Raise all wheels off floor.

2) Hold the tang plate disconnected from seat 
belt buckle.
3) Start the engine, and set the vehicle speed 
to more than 24 km/h (15 MPH).

NOTE:

The speed difference between front and rear
wheels may light the ABS or VDC warning light,
but this indicates no malfunction. When diagno-
sis is finished, perform the clear memory mode
for ABS or VDC. <Ref. to ABS(diag)-15, OPER-
ATION, Subaru Select Monitor.> or <Ref. to
VDC(diag)-16, OPERATION, Subaru Select
Monitor.> 

Does the seat belt warning 
light blink and the buzzer 
beep?

Go to step 10.

Replace the body 
integrated module.

10

CHECK SEAT BELT WARNING SYSTEM.
While the seat belt warning light is blinking and 
the buzzer is beeping, decelerate the vehicle 
speed to less than 21 km/h (13 MPH).

Does the buzzer stop beeping 
and the seat belt warning light 
change from blinking to illumi-
nating?

Go to step 11.

Replace the body 
integrated module.

11

CHECK SEAT BELT WARNING SYSTEM.
1) Set the vehicle speed to more than 24 km/h 
(15 MPH).
2) Wait for approx. 108 seconds while the seat 
belt warning light is blinking and the buzzer is 
beeping.

NOTE:

The speed difference between front and rear
wheels may light the ABS or VDC warning light,
but this indicates no malfunction. When diagno-
sis is finished, perform the clear memory mode
for ABS or VDC. <Ref. to ABS(diag)-15, OPER-
ATION, Subaru Select Monitor.> or <Ref. to
VDC(diag)-16, OPERATION, Subaru Select
Monitor.> 

Does the buzzer stop beeping 
and the seat belt warning light 
change from blinking to illumi-
nating?

The seat belt 
warning light sys-
tem is normal.
A temporary poor 
contact of har-
ness connector 
may be the cause. 
Check the poor 
contact.

Replace the body 
integrated module.

Step

Check

Yes

No

SB-12

SEAT BELT SYSTEM

Seat Belt Warning System

2. PASSENGER’S SEAT

Step

Check

Yes

No

1

CHECK BODY INTEGRATED MODULE.
Check DTC of body integrated module using 
Subaru Select Monitor. <Ref. to LAN(diag)-14, 
OPERATION, Subaru Select Monitor.>

Is DTC displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 2.

2

CHECK VEHICLE SPEED SIGNAL.
Check DTC of ABS or vehicle dynamics control 
(VDC) using Subaru Select Monitor. <Ref. to 
ABS(diag)-15, OPERATION, Subaru Select 
Monitor.> or <Ref. to VDC(diag)-16, OPERA-
TION, Subaru Select Monitor.> 

Is DTC displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 3.

3

CHECK BODY INTEGRATED MODULE.
1) Connect the Subaru Select Monitor to data 
link connector.
2) Turn the ignition switch to ON (engine 
OFF).
3) Turn the Subaru Select Monitor power 
switch to ON.
4) Read the data of “P seatbelt SW input” 
using Subaru Select Monitor. <Ref. to 
LAN(diag)-14, OPERATION, Subaru Select 
Monitor.>

Is the data of “P seatbelt SW 
input” “OFF”?

Go to step 4.

Check the harness 
between body inte-
grated module and 
chassis ground.

4

CHECK SEAT BELT WARNING LIGHT.
Read the data of “P-belt warning light O/P” 
using Subaru Select Monitor. <Ref. to 
LAN(diag)-14, OPERATION, Subaru Select 
Monitor.>

Is the data of “P-belt warning 
light O/P” “ON”? Or does the 
passenger’s seat belt warning 
light illuminate?

Go to step 5.

Check the harness 
between ignition 
switch and body 
integrated module.

5

CHECK BODY INTEGRATED MODULE.
1) Insert the tongue plate into the passenger’s 
seat belt buckle.
2) Read the data of “P seatbelt SW input” 
using Subaru Select Monitor. <Ref. to 
LAN(diag)-14, OPERATION, Subaru Select 
Monitor.>

Is the data of “P seatbelt SW 
input” “ON”?

Go to step 6.

Check the body 
integrated module.

6

CHECK SEAT BELT WARNING LIGHT.
Read the data of “P-belt warning light O/P” 
using Subaru Select Monitor. <Ref. to 
LAN(diag)-14, OPERATION, Subaru Select 
Monitor.>

Is the data of “P-belt warning 
light O/P” “OFF”? Or is the 
passenger’s seat belt warning 
light off?

Go to step 7.

Check the harness 
between ignition 
switch and body 
integrated module.

7

CHECK VEHICLE MODEL.

Is the vehicle EC, EK or KA 
model?

Go to step 8.

The seat belt 
warning light sys-
tem is normal at 
this time.
A temporary poor 
contact of har-
ness connector 
may be the cause. 
Check the poor 
contact.

8

CHECK SEAT BELT WARNING SYSTEM.
1) Hold the tang plate disconnected from seat 
belt buckle.
2) Turn the ignition switch to ON.

Does the seat belt warning 
light illuminate?

Go to step 9.

Check the body 
integrated module.