Subaru Legacy 2002 Service Manual page 3362

DIAGNOSTICS CHART WITH TROUBLE CODE (DTC)
No.
7 CHECK HARNESS OF COMMUNICATION
LINE.
Measure voltage between ECM harness con-
nector terminal and engine ground.
Connector & terminal
4-cylinder engine model:
(B135) No. 22, No.23 (+) — Engine
ground (−):
6-cylinder engine model:
(B135) No. 5, No.14 (+) — Engine
ground (−):
8 CHECK ECM BY INTERFACE CHECK.
1) Connect harness connector to ECM.
2) Disconnect harness connector from IMM
ECM.
3) Perform interface check. <Ref. to IM-8,
INTERFACE CHECK, OPERATION, Subaru
Select Monitor.>
9 CHECK ECM BY INTERFACE CHECK.
Perform interface check.
10 CHECK ECM BY INTERFACE CHECK.
Perform interface check.
Step
Is the voltage 0 V?
Does "Commun. Line
Shorted to Ground" appear
on screen?
Does "Commun. Line
Shorted to Battery" appear
on screen?
Does "Communication Line
not Shorted" appear on
screen?
IM-17
Check Yes
Go to step 8.
Replace ECM.
<Ref. to FU-51,
Engine Control
Module.> or <Ref.
to FU(w/oOBD)-
45, Engine Con-
trol Module.> or
<Ref. to FU(H6)-
47, Engine Con-
trol Module.>
Then perform
teaching opera-
tion. Refer to
teaching operation
manual (Pub. No.
S0820GZ).
Replace ECM.
<Ref. to FU-51,
Engine Control
Module.> or <Ref.
to FU(w/oOBD)-
45, Engine Con-
trol Module.> or
<Ref. to FU(H6)-
47, Engine Con-
trol Module.>
Then perform
teaching opera-
tion. Refer to
teaching operation
manual (Pub. No.
S0820GZ).
Replace IMM
ECM <Ref. to
SL-35, Immobi-
lizer Control Mod-
ule.> and then
replace all ignition
keys (including
the transponder).
Then perform
teaching opera-
tion. Refer to
teaching operation
manual (Pub. No.
S0820GZ).
Immobilizer (Diagnostics)
No
Repair harness
between IMM
ECM and ECM,
because there is
short circuit in
battery voltage
line or ignition
switch "ON" line.
Go to step 9.
Go to step 10.
When "Check
(Time Out)"
appears on
screen, perform
interface check
again.