Subaru Legacy 2004 Service Manual page 982

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK POWER SUPPLY TO EGR SOLE-
NOID VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from EGR sole-
noid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between EGR sole-
noid valve connector and engine ground.
Connector & terminal
(E18) No. 2 (+) — Engine ground (
(E18) No. 5 (+) — Engine ground (
2 CHECK HARNESS BETWEEN ECM AND
EGR SOLENOID VALVE CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the voltage between ECM and
EGR solenoid valve connector.
Connector & terminal
DTC P1492; (B134) No. 11 — (E18) No. 3:
DTC P1494; (B134) No. 10 — (E18) No. 1:
DTC P1496; (B134) No. 9 — (E18) No. 4:
DTC P1498; (B134) No. 8 — (E18) No. 6:
3 CHECK HARNESS BETWEEN ECM AND
EGR SOLENOID VALVE CONNECTOR.
1) Disconnect the connector from ECM.
2) Measure the resistance between ECM con-
nector and chassis ground.
Connector & terminal
DTC P1492; (B134) No. 11 — Chassis
ground:
DTC P1494; (B134) No. 10 — Chassis
ground:
DTC P1496; (B134) No. 9 — Chassis
ground:
DTC P1498; (B134) No. 8 — Chassis
ground:
4 CHECK POOR CONTACT.
Check poor contact in ECM connector and
EGR solenoid valve connector.
Check
Is the voltage more than 10 V? Go to step 2.
"
):
"
):
Is the resistance less than 1
!?
Is the resistance more than 1
M!?
Is there poor contact in ECM
connector or EGR solenoid
valve connector?
EN(H4SO 2.5)(diag)-223
ENGINE (DIAGNOSTICS)
Yes
Repair the har-
ness and connec-
tor.
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 the har-
ness and connec-
tor.
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 the ground
short in harness
between ECM and
EGR solenoid
valve connector.
Repair the poor Replace the EGR
contact in ECM solenoid valve.
connector or EGR <Ref. to FU(H4SO
solenoid valve 2.5)-30, EGR
connector. Valve.>
No