Subaru 2002 IMPREZA Service Manual page 1267

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
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
(B135) No. 9 (+) — Chassis ground ( − − − − ):
4 CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 9 (+) — Chassis ground ( − − − − ):
5 CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 8 (+) — Chassis ground ( − − − − ):
6 CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from pressure
sensor.
3)Turn the ignition switch to ON.
4)Measure the voltage between pressure sen-
sor connector and engine ground.
Connector & terminal
(E21) No. 3 (+) — Engine ground ( − − − − ):
7 CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ECM.
3)Measure the resistance of harness between
ECM and intake manifold pressure sensor con-
nector.
Connector & terminal
(B135) No. 19 — (E21) No. 2:
8 CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
Measure the resistance of harness between
intake manifold pressure sensor connector and
engine ground.
Connector & terminal
(E21) No. 1 — Engine ground:
Check
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 0.7 V? Go to step 6.
Is the voltage more than 4.5 V? Go to step 7.
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
EN(TURBO)-107
ENGINE (DIAGNOSTICS)
Yes
Repair the poor Even if MIL lights
contact in ECM or up, the circuit has
pressure sensor returned to a nor-
connector. mal condition at
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.
Contact with your
Subaru distributor
service.
NOTE:
Inspection by DTM
is required,
cause
cause is deteriora-
tion of
parts.
Repair the open
circuit in harness
between ECM and
intake manifold
pressure sensor
connector.
Go to step 8. Repair the open
circuit in harness
between ECM and
intake manifold
pressure sensor
connector.
Go to step 9. Repair the ground
short circuit in har-
ness between
ECM and intake
manifold pressure
sensor connector.
No
be-
probable
multiple
be-
probable
multiple