Subaru 2002 IMPREZA Service Manual page 663

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK CURRENT DATA.
1)Start the engine.
2)Read the data of intake manifold absolute
pressure signal using Subaru Select Monitor or
OBD-II general scan tool.
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
•OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.
2 CHECK POOR CONTACT.
Check poor contact in ECM and pressure sen-
sor connector.
3 CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground ( − − − − ):
4 CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground ( − − − − ):
5 CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B136) No. 29 (+) — Chassis ground ( − − − − ):
6 CHECK INPUT SIGNAL FOR ECM. (USING
SUBARU SELECT MONITOR.)
Read the data of atmospheric absolute pres-
sure signal using Subaru Select Monitor.
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
Check
Is the value less than 0 kPa
(0 mmHg, 0 inHg)?
Is there poor contact in ECM or
pressure sensor connector?
Is the voltage more than 4.5 V? Go to step 5.
Does the voltage change more
than 4.5 V by shaking harness
and connector of ECM while
monitoring the value with volt-
age meter?
Is the voltage less than 0.2 V? Go to step 7.
Does the value change more
than 0 kPa (0 mmHg, 0 inHg)
by shaking harness and con-
nector of ECM while monitor-
ing the value with Subaru
select monitor?
EN-231
ENGINE (DIAGNOSTICS)
Yes
Go to step 3. Go to step 2.
Repair the poor Even if MIL lights
contact in ECM or up, the circuit has
atmospheric pres- returned to a nor-
sure sensor con- mal condition at
nector. this time.
Go to step 4.
Repair the poor Contact with your
contact in ECM Subaru distributor
connector. service.
NOTE:
Inspection by DTM
is required,
cause
cause is deteriora-
tion of
parts.
Go to step 6.
Repair the poor Go to step 7.
contact in ECM
connector.
No
be-
probable
multiple