Subaru Legacy 2002 Service Manual page 774

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK POWER SUPPLY TO IDLE AIR
CONTROL SOLENOID VALVE.
1) Turn ignition switch to OFF.
2) Disconnect connector from idle air control
solenoid valve.
3) Turn ignition switch to ON.
4) Measure voltage between idle air control
solenoid valve connector and engine ground.
Connector & terminal
(E7) No. 2 (+) — Engine ground (−):
2 CHECK POWER SUPPLY TO IDLE AIR
CONTROL SOLENOID VALVE.
Measure voltage between idle air control sole-
noid valve connector and engine ground.
Connector & terminal
(E7) No. 5 (+) — Engine ground (−):
3 CHECK HARNESS BETWEEN ECM AND
IDLE AIR CONTROL SOLENOID VALVE
CONNECTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between ECM and idle
air control solenoid valve connector.
Connector & terminal
DTC P1510; (B134) No. 5 — (E7) No. 3:
DTC P1512; (B134) No. 6 — (E7) No. 1:
DTC P1514; (B134) No. 19 — (E7) No.
6:
DTC P1516; (B134) No. 20 — (E7) No.
4:
4 CHECK HARNESS BETWEEN ECM AND
IDLE AIR CONTROL SOLENOID VALVE
CONNECTOR.
1) Disconnect connector from ECM.
2) Measure resistance between ECM connec-
tor and chassis ground.
Connector & terminal
DTC P1510; (B134) No. 5 — Chassis
ground:
DTC P1512; (B134) No. 6 — Chassis
ground:
DTC P1514; (B134) No. 19 — Chassis
ground:
DTC P1516; (B134) No. 20 — Chassis
ground:
Step
Is the voltage more than 10
V?
Is the voltage more than 10
V?
Is the resistance less than
1 Ω?
Is the resistance less than
10 Ω?
EN-257
Check Yes
Go to step 2.
Go to step 3.
Go to step 4.
Repair ground
short circuit in
harness between
ECM and idle air
control solenoid
valve connector.
Engine (Diagnostics)
No
Repair harness
and connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
idle air control
solenoid valve
and main relay
connector
¼ Poor contact in
coupling connec-
tor (B22)
Repair harness
and connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
idle air control
solenoid valve
and main relay
connector
¼ Poor contact in
coupling connec-
tor (B22)
Repair harness
and connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
ECM and idle air
control solenoid
valve connector
¼ Poor contact in
coupling connec-
tor (B21)
Go to step 5.