Subaru Legacy 2003 Service Manual page 589

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
5 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to OFF.
2) Connect connectors to ECM and EGR sole-
noid valve.
3) Turn ignition switch to ON.
4) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B134) No. 15 — Chassis ground:
(B134) No. 16 — Chassis ground:
(B134) No. 17 — Chassis ground:
(B134) No. 18 — Chassis ground:
Does the measured value change within
specified range?
6 CHECK HARNESS BETWEEN EGR SOLE-
NOID VALVE AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from EGR solenoid
valve and ECM.
3) Measure resistance of harness between
EGR solenoid valve and ECM connector.
Connector & terminal
(B134) No. 18 — (E18) No. 6:
(B134) No. 17 — (E18) No. 1:
(B134) No. 16 — (E18) No. 4:
(B134) No. 15 — (E18) No. 3:
Is the measured value less than the speci-
fied value?
7 CHECK HARNESS BETWEEN EGR SOLE-
NOID VALVE AND ECM CONNECTOR.
Measure resistance of harness between EGR
solenoid valve and chassis ground.
Connector & terminal
(B134) No. 18 — Chassis ground:
(B134) No. 17 — Chassis ground:
(B134) No. 16 — Chassis ground:
(B134) No. 15 — Chassis ground:
Does the measured value exceed the specified
value?
8 CHECK POOR CONTACT.
Check poor contact in ECM and EGR solenoid
valve connector.
Is there poor contact in ECM and EGR sole-
noid valve connector?
Step
EN(H4SO)-192
Value
0 — 10 V
1 Ω
1 MΩ
There is poor contact.
Yes
Repair poor con- Go to step 6.
tact in ECM con-
nector.
Go to step 7. Repair open circuit
in harness
between ECM and
EGR solenoid
valve connector.
Go to step 8. Repair short circuit
in harness
between main
relay and EGR
solenoid valve
connector.
Repair poor con- Even if MI lights
tact in ECM and up, the circuit has
EGR solenoid returned to a nor-
valve connector. mal condition at
this time.
No