Subaru Legacy 2004 Service Manual page 857

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK OPTION CODE.
2 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of intake manifold absolute
pressure signal using Subaru Select Monitor.
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO 2.5)(diag)-26, Subaru Select Mon-
itor.>
3 CHECK POOR CONTACT.
Check the poor contact in ECM and manifold
pressure sensor connector.
4 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 16 (+) — Chassis ground (
5 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 16 (+) — Chassis ground (
6 CHECK INPUT SIGNAL TO ECM.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B136) No. 22 (+) — Chassis ground (
7 CHECK INPUT SIGNAL TO ECM (USING
SUBARU SELECT MONITOR).
Read the data of atmospheric absolute pres-
sure signal using Subaru Select Monitor.
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO 2.5)(diag)-26, Subaru Select Mon-
itor.>
Check
Is the option code EC, EK or
K4?
Is the value less than 13.3 kPa
(100 mmHg, 3.94 inHg)?
Is there poor contact in ECM or
manifold pressure sensor con-
nector?
Is the voltage more than 4.5 V? Go to step 6.
"
):
Does the voltage change when
shaking the ECM harness and
connector?
"
):
Is the voltage less than 0.2 V? Go to step 8.
"
):
Is the value more than 13.3
kPa (100 mmHg, 3.94 inHg)
when shaking the ECM har-
ness and connector?
EN(H4SO 2.5)(diag)-98
Yes
Go to step 2. Refer to EN(H4SO
2.0) section. <Ref.
to EN(H4SO
2.0)(diag)-66, List
of Diagnostic Trou-
ble Code (DTC).>
NOTE:
Fuel injection sys-
tem for KA and KS
model is the same
as 2.0 L model.
Go to step 4. Go to step 3.
Repair the poor Even if the mal-
contact in ECM or function indicator
manifold pressure light illuminates,
sensor connector. the circuit has
returned to a nor-
mal condition at
this time.
Go to step 5.
Repair the poor Replace the ECM.
contact in ECM <Ref. to FU(H4SO
connector. 2.5)-36, Engine
Control Module
(ECM).>
Go to step 7.
Repair the poor Go to step 8.
contact in ECM
connector.
No