Subaru 2002 IMPREZA Service Manual page 693

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK ANY OTHER DIAGNOSTIC TROU-
BLE CODE (DTC) ON DISPLAY.
2 CHECK GROUND CIRCUIT FOR ECM.
1)Turn the ignition switch to OFF.
2)Measure the resistance between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 21 — Chassis ground:
(B136) No. 22 — Chassis ground:
3 CHECK HARNESS BETWEEN ECM AND
IDLE AIR CONTROL SOLENOID VALVE
CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from idle air con-
trol solenoid valve.
3)Turn the ignition switch to ON.
4)Measure the voltage between ECM connec-
tor and chassis ground.
Connector & terminal
DTC P1511; (B134) No. 5 (+) — Chassis
ground (–):
DTC P1513; (B134) No. 6 (+) — Chassis
ground (–):
DTC P1515; (B134) No. 19 (+) — Chassis
ground (–):
DTC P1517; (B134) No. 20 (+) — Chassis
ground (–):
Check
Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC P1511, P1513,
P1515 and P1517 at same
time?
Is the resistance less than 5
Ω?
Is the voltage more than 10 V? Repair the battery
EN-261
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Go to step 3.
Go to step 3. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM connector
and engine ground
terminal
• Poor contact in
ECM connector
• Poor contact in
coupling connector
(B22)
Replace the ECM.
short circuit in har- <Ref. to FU-51,
ness between Engine Control
ECM and idle air Module.>
control solenoid
valve connector.
After repair,
replace the ECM.
<Ref. to FU-51,
Engine Control
Module.>
No