Subaru Legacy 2003 Service Manual page 604

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK SPEEDOMETER AND TACHOME-
TER OPERATION IN COMBINATION
METER.
Does speedometer and tachometer operate
normally?
2 CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to ON. (Engine OFF)
2) Measure voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 27 (+) — Chassis ground ( − − − − ):
Is the measured value less than the speci-
fied value?
3 CHECK INPUT SIGNAL FOR ECM. (USING
SUBARU SELECT MONITOR.)
Read data of fuel level sensor signal using
Subaru Select Monitor.
Is the measured value less than the specified
value by shaking harness and connector of
ECM while monitoring the value with Subaru
Select Monitor?
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN(H4SO)-32, Subaru Select Moni-
tor.>
4 CHECK INPUT VOLTAGE OF ECM.
1) Turn ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Turn ignition switch to ON.
4) Measure voltage of harness between ECM
connector and chassis ground.
Connector & terminal
(B136) No. 27 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
5 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
1) Turn ignition switch to OFF.
2) Disconnect connector from connector (i10)
and ECM connector.
3) Measure resistance between ECM and
chassis ground.
Connector & terminal
(B136) No. 27 — Chassis ground:
Does the measured value exceed the spec-
ified value?
Value
Operates normally.
0.12 V
0.12 V
0.12 V
1 MΩ
EN(H4SO)-207
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair or replace
combination
meter. <Ref. to
IDI-4, Combina-
tion Meter Sys-
tem.>
Go to step 6. Go to step 3.
Repair poor con- Even if MI lights
tact in ECM con- up, the circuit has
nector. returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector
may be the cause.
NOTE:
In this case, repair
the following:
• Poor contact in
combination meter
connector
• Poor contact in
ECM connector
• Poor contact in
coupling connec-
tors
Go to step 4. Go to step 7.
Go to step 6. Repair ground
short circuit in har-
ness between
ECM and combi-
nation meter con-
nector.
No