Subaru Legacy 2003 Service Manual page 1948

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of throttle position sensor
signal using Subaru Select Monitor.
Does the measured value exceed the spec-
ified value?
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOSTC)-26, Subaru Select Monitor.>
2 CHECK HARNESS BETWEEN THROTTLE
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from throttle posi-
tion sensor.
3) Measure the resistance of harness
between throttle position sensor connector
and engine ground.
Connector & terminal
(E13) No. 2 — Engine ground:
Is the measured value less than the speci-
fied value?
3 CHECK HARNESS BETWEEN THROTTLE
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between throttle posi-
tion sensor connector and engine ground.
Connector & terminal
(E13) No. 3 (+) — Engine ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
Value
4.7 V
5 Ω
4.7 V
EN(H4DOSTC)-109
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Even if MI lights
up, the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector
may be the cause.
NOTE:
In this case, repair
the following:
• Poor contact in
throttle position
sensor connector
• Poor contact in
ECM connector
• Poor contact in
coupling connector
Go to step 3. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
throttle position
sensor and ECM
connector
• Poor contact in
coupling connector
• Poor contact in
joint connector
Repair the battery Replace the throt-
short circuit in har- tle position sensor.
ness between <Ref. to
throttle position FU(H4DOSTC)-
sensor and ECM 32, Throttle Posi-
connector. After tion Sensor.>
repair, replace the
ECM. <Ref. to
FU(H4DOSTC)-
40, Engine Con-
trol Module.>
No