Subaru Legacy 2002 Service Manual page 746

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK CURRENT DATA.
1) Start engine.
2) Read the data of intake manifold absolute
pressure signal using Subaru Select Monitor
or OBD-II general scan tool.
NOTE:
¼ Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
¼ 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
sensor connector.
3 CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground
(−):
4 CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground
(−):
5 CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM and chassis
ground.
Connector & terminal
(B136) No. 29 (+) — Chassis ground
(−):
6 CHECK INPUT SIGNAL FOR ECM. (USING
SUBARU SELECT MONITOR.)
Read data of atmospheric absolute pressure
signal using Subaru Select Monitor.
NOTE:
¼ Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
Step
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?
Does the voltage change
more than 4.5 V by shaking
harness and connector of
ECM while monitoring the
value with voltage meter?
Is the voltage less than 0.2
V?
Does the value change
more than 0 kPa (0 mmHg,
0 inHg) by shaking harness
and connector of ECM
while monitoring the value
with Subaru select moni-
tor?
EN-229
Check Yes
Go to step 3.
Repair poor con-
tact in ECM or
atmospheric pres-
sure sensor con-
nector.
Go to step 5.
Repair poor con-
tact in ECM con-
nector.
Go to step 7.
Repair poor con-
tact in ECM con-
nector.
Engine (Diagnostics)
No
Go to step 2.
Even if MIL lights
up, the circuit has
returned to a nor-
mal condition at
this time.
Go to step 4.
Contact with your
Subaru distributor.
NOTE:
Inspection by
DTM is required,
because probable
cause is deterio-
ration of multiple
parts.
Go to step 6.
Go to step 7.