Subaru Legacy 2003 Service Manual page 505

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
7 CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from pressure sen-
sor.
3) Turn ignition switch to ON.
4) Measure voltage between intake air tem-
perature sensor and pressure sensor con-
nector and engine ground.
Connector & terminal
(E21) No. 3 (+) — Engine ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
8 CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between
ECM and pressure sensor connector.
Connector & terminal
(B135) No. 19 — (E21) No. 1:
Is the measured value less than the speci-
fied value?
9 CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
Measure resistance of harness between pres-
sure sensor connector and engine ground.
Connector & terminal
(E21) No. 2 — Engine ground:
Does the measured value exceed the specified
value?
10 CHECK POOR CONTACT.
Check poor contact in intake manifold pressure
sensor connector.
Is there poor contact in intake manifold pres-
sure sensor connector?
Step
EN(H4SO)-108
Value
4.5 V
1 Ω
500 kΩ
There is poor contact.
Yes
Go to step 8. Repair open circuit
in harness
between ECM and
pressure sensor
connector.
Go to step 9. Repair open circuit
in harness
between ECM and
pressure sensor
connector.
Go to step 10. Repair ground
short circuit in har-
ness between
ECM and intake
air temperature
and pressure sen-
sor connector.
Repair poor con- Replace pressure
tact in pressure sensor. <Ref. to
sensor connector. FU(H4SO)-32,
Pressure Sensor.>
No