Subaru FORESTER 2001 Service Manual page 168

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B137) No. 24 (+) — Chassis ground
(−):
2 CHECK HARNESS BETWEEN WASTEGATE
CONTROL SOLENOID VALVE AND ECM
CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from wastegate
control solenoid valve and ECM.
3) Measure resistance of harness between
wastegate control solenoid valve connector
and engine ground.
Connector & terminal
(B127) No. 1 — Engine ground:
3 CHECK HARNESS BETWEEN WASTEGATE
CONTROL SOLENOID VALVE AND ECM
CONNECTOR.
Measure resistance of harness between ECM
and wastegate control solenoid valve of har-
ness connector.
Connector & terminal
(B137) No. 24 — (B127) No. 1:
4 CHECK WASTEGATE CONTROL SOLE-
NOID VALVE.
1) Remove wastegate control solenoid valve.
2) Measure resistance between purge control
solenoid valve terminals.
Terminals
No. 1 — No. 2:
5 CHECK POWER SUPPLY TO WASTEGATE
CONTROL SOLENOID VALVE.
1) Turn ignition switch to ON.
2) Measure voltage between wastegate con-
trol solenoid valve and engine ground.
Connector & terminal
(B127) No. 2 (+) — Engine ground (−):
Step
Is the voltage more than 10
V?
Is the resistance less than
10 Ω?
Is the resistance less than
1 Ω?
Is the resistance between
30 and 34 Ω?
Is the voltage more than 10
V?
EN(DOHC TURBO)-167
Check Yes
Even if MIL lights
up, the circuit has
returned to a nor-
mal condition at
this time. Contact
with your Subaru
distributor.
NOTE:
Inspection by
DTM is required,
because probable
cause is deterio-
ration of multiple
parts.
Repair ground
short circuit in
harness between
ECM and waste-
gate control sole-
noid valve con-
nector.
Go to step 4.
Go to step 5.
Go to step 6.
Engine (Diagnostics)
No
Go to step 2.
Go to step 3.
Repair open cir-
cuit in harness
between ECM
and wastegate
control solenoid
valve connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
ECM and waste-
gate control sole-
noid valve con-
nector
Replace waste-
gate control sole-
noid valve. <Ref.
to FU(DOHC
TURBO)-41,
Wastegate Control
Solenoid Valve.>
Repair open cir-
cuit in harness
between main
relay and waste-
gate control sole-
noid valve con-
nector.