Subaru 2002 IMPREZA Service Manual page 626

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
3 CHECK INPUT SIGNAL FOR ECM. (USING
SUBARU SELECT MONITOR.)
Read the data of fuel level sensor signal using
Subaru Select Monitor.
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
4 CHECK INPUT VOLTAGE OF ECM.
1)Turn the ignition switch to OFF.
2)Separate the fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3)Turn the ignition switch to ON.
4)Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B136) No. 27 (+) — Chassis ground ( − − − − ):
5 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from connector
(i10) and ECM connector.
3)Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B136) No. 27 — Chassis ground:
6 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
Measure the resistance between ECM and
combination meter connector.
Connector & terminal
(B136) No. 27 — (i12) No. 2:
7 CHECK ENGINE DISPLACEMENT.
8 CHECK FUEL TANK CORD.
1)Disconnect the connector from fuel pump
assembly.
2)Measure the resistance between fuel pump
assembly and chassis ground.
Connector & terminal
(R58) No. 3 — Chassis ground:
Check
Does the value change less
than 0.12 V by shaking har-
ness and connector of ECM
while monitoring the value with
Subaru Select Monitor?
Is the voltage more than 0.12
V?
Is the resistance more than 1
MΩ?
Is the resistance less than 10
Ω?
Is the engine displacement 2.5
L?
Is the resistance more than 1
MΩ?
EN-194
Yes
Repair the poor Even if MIL lights
contact in ECM up, the circuit has
connector. 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 (B99)
Go to step 4. Go to step 8.
Go to step 6. Repair the ground
short circuit in har-
ness between
ECM and combi-
nation meter con-
nector.
Repair or replace Repair the open
the combination circuit between
meter. <Ref. to ECM and combi-
IDI-4, Combina- nation meter con-
tion Meter Sys- nector.
tem.>
NOTE:
In this case, repair
the following:
Poor contact in
coupling connector
(i2)
Go to step 10. Go to step 8.
Go to step 9. Repair the ground
short circuit in fuel
tank cord.
No