Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 667

SB-13

Inspection Locations after a Collision

SEAT BELT SYSTEM

3. Inspection Locations after a

Collision

A: INSPECTION

Refer to “Inspection Locations after a Collision” of

Airbag section. <Ref. to AB-12, Inspection Loca-

tions after a Collision.>

SB-14

Seat Belt Warning System

SEAT BELT SYSTEM

4. Seat Belt Warning System

A: WIRING DIAGRAM

Refer to “Seat Belt Warning System” in the wiring diagram. <Ref. to WI-86, WIRING DIAGRAM, Seat Belt

Warning System.>

B: INSPECTION

CAUTION:

• Before diagnosing the airbag system, be sure to turn the ignition switch to OFF, disconnect the

ground cable from battery, and wait 60 seconds or more before starting to work.

• When replacing the airbag module, seat belt pretensioner, roll connector, control module and sen-

sor, reconnect each part and check that the warning light operates properly.

• When inspecting the airbag main harness, disconnect the airbag module connectors of the driver’s

and passenger’s seats for safety.

• When inspecting the airbag rear harness, disconnect the side airbag module connector, curtain

airbag module connector and seat belt pretensioner connector for safety reasons.

TROUBLE SYMPTOM:

• Driver’s side seat belt warning light does not illuminate or it remains illuminating.

• Warning buzzer does not beep.

Step

Check

Yes

No

1

CHECK CURRENT SETTINGS.
1) Prepare the Subaru Select Monitor.
2) Turn the ignition switch to ON (engine OFF)
and run the “PC application for Subaru Select
Monitor”.
3) Select the “current data display” and read
the data of the “Belt Warning Switch”.

Is the belt warning display ON? Go to step

2.

Turn the belt warn-
ing ON with unit
customization.

2

CHECK CURRENT DATA.
1) Select the “current data display” and read
the data of the “IG power supply voltage”.
2) Turn the ignition switch ON ←→ OFF.

Does the voltage change
between 9 V or higher ←→ less
than 1.5 V, according to the
ignition switch ON ←→ OFF
operation?

Go to step

3.

Check the ignition
switch circuit.

3

CHECK FUNCTION.
1) Sit on the driver’s seat and passenger’s seat
and disconnect the seat belts of the both.
2) Turn the ignition switch to ON (engine OFF).
3) Check if the driver’s seat belt warning light in
the combination meter and the passenger’s
seat belt warning light in the clock unit illumi-
nate, and if the warning buzzer sounds.

Do the driver’s warning light
and passenger’s warning light
blink and the buzzer sound
while blinking?

Go to step

4.

• Malfunction of
the driver’s seat
belt warning light

→Go to step 10.
• Malfunction of
the passenger’s
seat belt warning
light →Go to step
16.
• The buzzer does
not sound →Go to
step

6.

4

CHECK FUNCTION.
1) Wait until the buzzer stops sounding in step
3. (for approximately six seconds after starting
sounding)
2) Connect and disconnect the seat belts of
the driver’s and passenger’s.
3) Check if the driver’s seat belt warning light in
the combination meter and the passenger’s
seat belt warning light in the clock unit illumi-
nate, and if the warning buzzer sounds.

Do the seat belts warning light
illuminate ←→ go off according
to the operation?

Go to step

5.

• Malfunction of
the driver’s seat
belt warning light

→Go to step 6.
• Malfunction of
the passenger’s
seat belt warning
light →Go to step
12.

SB-15

Seat Belt Warning System

SEAT BELT SYSTEM

5

CHECK FUNCTION.
1) Wait until the buzzer stops sounding in step
3. (for approximately six seconds after starting
sounding)
2) Start the engine, and set the vehicle speed
at 15 km/h (9 MPH) or more.
3) Check the seat belt warning lights of the
driver’s and the passenger’s, and if the warning
buzzer sounds.

Do the driver’s warning light
and passenger’s warning light
blink and the buzzer sound
while blinking?

Seat belt warning
system is normal.

Go to step

19.

6

CHECK CURRENT DATA.
1) Select the “current data display” and read
the data of the seat belt switch of the driver’s.
2) Fasten and detach the driver’s side seat belt
buckle, and read the data of the seat belt switch.
<Ref. to LAN(diag)-30, OPERATION, Read
Current Data.>

Does the seat belt switch dis-
play turn ON ←→ OFF accord-
ing to the operation of the seat
belt buckle?

Go to step

10.

Go to step

7.

7

CHECK HARNESS.
1) Disconnect the negative terminal from the
battery, and wait for 60 seconds or more.
2) Disconnect the connector of body inte-
grated unit and the seat belt buckle switch.
3) Check for a short circuit to battery, open cir-
cuit or short circuit to ground between the body
integrated unit and the driver’s seat belt buckle
switch.

Connector & terminal

(B281) No. 16 — (R107) No. 3:

Is the harness normal?

Go to step

8.

Repair or replace
the harness.

8

CHECK HARNESS.
Measure the resistance between the driver’s
seat belt buckle switch and chassis ground.

Connector & terminal

(R107) No. 1 — Chassis ground:

Is the resistance less than 10

Ω?

Go to step

9.

Repair or replace
the harness.

9

CHECK DRIVER’S SEAT BELT BUCKLE
SWITCH LH.
Measure the resistance between the connector
terminals of the driver’s seat belt switch when
the driver’s seat belt is fastened and detached.

Connector & terminal

(R107) No. 1 — (R107) No. 3:

Is the resistance when the belt
is fastened 1 MΩ or more, and
less than 10 Ω when the belt is
detached?

Replace the body
integrated unit.
<Ref. to SL-48,
REMOVAL, Body
Integrated Unit.>

Replace the
driver’s side inner
belt assembly.
<Ref. to SB-18,
INNER SEAT BELT
ASSEMBLY,
REMOVAL, Front
Seat Belt.>

10

CHECK DTC.
Read the DTC using Subaru Select Monitor.

Is any CAN-related body sys-
tem DTC detected?

Check the CAN
system according
to the DTC.

Go to step

11.

11

CHECK COMBINATION METER.
Perform the self-diagnosis of combination
meter. <Ref. to IDI-5, SELF-DIAGNOSIS,
INSPECTION, Combination Meter System.>

At the start of combination
meter self diagnosis, did the
buzzer sound and the seat belt
warning light illuminate?

Replace the body
integrated unit or
the combination
meter. Or replace
both. It may be due
to the transmis-
sion failure of the
body integrated
unit or the recep-
tion failure of the
combination meter.

Replace the com-
bination meter.
<Ref. to IDI-16,
REMOVAL, Com-
bination Meter.>

Step

Check

Yes

No

SB-16

Seat Belt Warning System

SEAT BELT SYSTEM

12

CHECK CURRENT DATA.
1) Sit in the passenger’s seat.
2) Select “Current Data Display” and display
the data of “P seatbelt SW input”.
3) Fasten and detach the passenger’s side
seat belt buckle, and read the data of the seat
belt switch. <Ref. to LAN(diag)-30, OPERA-
TION, Read Current Data.>

Does the seat belt switch dis-
play turn ON ←→ OFF accord-
ing to the operation of the seat
belt buckle?

Go to step

16.

Go to step

13.

13

CHECK AIRBAG SYSTEM AND OCCUPANT
DETECTION SYSTEM.
Perform the check in accordance with the diag-
nostic procedure DTC 27 of the airbag system.
<Ref. to AB(diag)-69, DTC 27 ODS COMMUNI-
CATION ERROR, Diagnostic Chart with Trouble
Code.>

Is there any problem on the
inspection result?

Go to step

14.

Replace with new
parts according to
DTC 27.

14

CHECK BUCKLE SWITCH RH.
Perform the check in accordance with the diag-
nostic procedure DTC 37 of the occupant
detection system. <Ref. to OD(diag)-27, DTC
37 BUCKLE SWITCH RH FAILURE, Diagnostic
Procedure with Diagnostic Trouble Code
(DTC).>

Is there any problem on the
inspection result?

Go to step

15.

Replace with new
parts according to
DTC 37.

15

CHECK AIRBAG CONTROL MODULE AND
BODY INTEGRATED UNIT.
Check the airbag control module, occupant
detection sensor and seat belt buckle switch
RH.
Perform the check in accordance with the diag-
nostic procedure DTC 39 of the airbag system.
<Ref. to AB(diag)-72, DTC 39 SEAT BELT
WARNING FAILURE, Diagnostic Chart with
Trouble Code.>

Is there any problem on the
inspection result?

Replace the body
integrated unit.
<Ref. to SL-48,
REMOVAL, Body
Integrated Unit.>

Replace with new
parts according to
DTC 39.

16

CHECK HARNESS.
1) Disconnect the clock connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between body inte-
grated unit and clock.

Connector & terminal

(i59) No. 8 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step

17.

Repair or replace
the harness.

17

CHECK HARNESS.
1) Turn the ignition switch to ON.
2) Disconnect the connector of body inte-
grated unit.
3) Check for battery short and open circuits,
and short to ground between the body inte-
grated unit and clock.

Connector & terminal

(i84) No. 25 — (i59) No. 2:

Is the harness normal?

Go to step

18.

Repair or replace
the harness.

18

CHECK CLOCK.
1) Connect the clock connector.
2) Turn the ignition switch to ON.
3) Use an appropriate wiring harness to create
a short between the body integrated unit and
clock.

Connector & terminal

(i84) No. 25 — Chassis ground:
(i59) No. 2 — Chassis ground:

Does passenger’s seat belt
warning light in the clock illumi-
nate?

Replace the body
integrated unit.
<Ref. to SL-48,
REMOVAL, Body
Integrated Unit.>

Replace the clock.
<Ref. to IDI-21,
REMOVAL,
Clock.>

19

CHECK DTC.
Read the DTCs for all systems using the Sub-
aru Select Monitor.

Is a DTC detected?

Perform a check
according to the
DTC.

Go to step

20.

Step

Check

Yes

No