Subaru 2009 IMPREZA Service Manual page 2937

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the occupant detection control module
and belt tension sensor.
2 CHECK BELT TENSION SENSOR.
1) Turn the ignition switch to OFF, disconnect
the ground cable from battery, and wait for 20
seconds or more.
2) Disconnect the belt tension sensor connec-
tor (AB56) from the airbag harness.
3) Connect the test harness AC to the connec-
tor (AB56).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
3 CHECK AIRBAG HARNESS.
1) Turn the ignition switch to OFF, disconnect
the ground cable from battery, and wait for 20
seconds or more.
2) Disconnect the test harness AC from the
belt tension sensor connector (AB56).
3) Connect the test harness AD (1AD) to the
connector (AB56).
4) Disconnect the airbag harness connector
(AB53), and connect connector (1AB) of test
harness AB.
5) Measure the resistance between test har-
ness terminals.
Connector & terminal
(2AB) No. 5 — (2AD) No. 1:
(2AB) No. 4 — (2AD) No. 3:
(2AB) No. 6 — (2AD) No. 2:
4 CHECK AIRBAG HARNESS.
Measure the resistance between test harness
terminals, and between test harness terminal
and chassis ground.
Connector & terminal
(2AB) No. 4 — (2AD) No. 1:
(2AB) No. 4 — (2AD) No. 2:
(2AB) No. 4 — chassis ground:
(2AB) No. 5 — (2AD) No. 2:
(2AB) No. 5 — chassis ground:
5 CHECK AIRBAG HARNESS.
1) Connect the battery ground terminal and
turn the ignition switch to ON.
2) Measure the voltage between test harness
and chassis ground.
Connector & terminal
(2AD) No. 1 (+) — Chassis ground (–):
(2AD) No. 3 (+) — Chassis ground (–):
D: DTC 27 ODS COMMUNICATION ERROR
Perform the diagnosis following diagnostic procedures for the airbag system. <Ref. to AB(diag)-60, DTC 27
ODS COMMUNICATION ERROR, Diagnostic Chart with Trouble Code.>
OCCUPANT DETECTION SYSTEM (DIAGNOSTICS)
Check
Is there poor contact?
Does the airbag warning light
illuminate for approximately 6
seconds and go off?
Is the resistance less than 10 ? Go to step 4.
Is the resistance 1 M or
more?
Is the voltage 1 V or less?
OD(diag)-25
Yes No
Reconnect the Go to step 2.
connector. If the
fault is not fixed,
replace the airbag
harness.
Replace the seat Go to step 3.
belt outer. <Ref. to
SB-17, OUTER
SEAT BELT
ASSEMBLY,
REMOVAL, Front
Seat Belt.>
Replace the airbag
harness along with
chassis harness.
Go to step 5.
Replace the airbag
harness along with
chassis harness.
Replace the airbag Check the seat
harness along with harness, and if any
chassis harness. fault is found,
replace the seat
harness. If no fault
is found in the seat
harness, replace
the seat cushion
frame assembly.
<Ref. to SE-8,
PASSENGER'S
SEAT, DISASSEM-
BLY, Front Seat.>