Subaru Legacy 2003 Service Manual page 678

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK POWER SUPPLY TO EGR SOLE-
NOID VALVE.
1) Turn ignition switch to OFF.
2) Disconnect connector from EGR solenoid
valve.
3) Turn ignition switch to ON.
4) Measure voltage between EGR solenoid
valve connector and engine ground.
Connector & terminal
(E18) No. 2 (+) - Engine ground (-):
(E18) No. 5 (+) - Engine ground (-):
Does the measured value exceed the spec-
ified value?
2 CHECK HARNESS BETWEEN ECM AND
EGR SOLENOID VALVE CONNECTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between ECM and
EGR solenoid valve connector.
Connector & terminal
DTC P1492; (B134) No. 18 - (E18) No. 6:
DTC P1494; (B134) No. 17 - (E18) No. 1:
DTC P1496; (B134) No. 16 - (E18) No. 4:
DTC P1498; (B134) No. 15 - (E18) No. 3:
Is the measured value less than the speci-
fied value?
3 CHECK HARNESS BETWEEN ECM AND
EGR SOLENOID VALVE CONNECTOR.
1) Disconnect connector from ECM.
2) Measure resistance between ECM connec-
tor and chassis ground.
Connector & terminal
DTC P1492; (B134) No. 18 - Chassis
ground:
DTC P1494; (B134) No. 17 - Chassis
ground:
DTC P1496; (B134) No. 16 - Chassis
ground:
DTC P1498; (B134) No. 15 - Chassis
ground:
Does the measured value exceed the spec-
ified value?
4 CHECK POOR CONTACT.
Check poor contact between ECM connector
and EGR solenoid valve connector.
Is there poor contact of ECM connector or
EGR solenoid valve connector?
Value
10 V
1 Ω
1 MΩ
There is poor contact.
EN(H4SO)-281
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
EGR solenoid
valve and main
relay connector
• Poor contact in
coupling connector
Go to step 3. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and EGR
solenoid valve
connector
• Poor contact in
coupling connector
Go to step 4. Repair ground
short circuit
between ECM and
EGR solenoid
valve connector.
Repair poor con- Replace EGR
tact of ECM con- solenoid valve.
nector or EGR <Ref. to
solenoid valve FU(H4SO)-35,
connector. EGR Valve.>
No