Subaru Legacy 2002 Service Manual page 652

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK CURRENT DATA.
1) Start engine.
2) Read data of throttle position sensor signal
using Subaru Select Monitor or OBD-II gen-
eral 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 HARNESS BETWEEN THROTTLE
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from throttle position
sensor.
3) Measure resistance of harness between
throttle position sensor connector and engine
ground.
Connector & terminal
(E13) No. 2 — Engine ground:
3 CHECK HARNESS BETWEEN THROTTLE
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn ignition switch to ON.
2) Measure voltage between throttle position
sensor connector and engine ground.
Connector & terminal
(E13) No. 3 (+) — Engine ground (−):
Step
Is the value more than 4.9
V?
Is the resistance less than
5 Ω?
Is the voltage more than
4.9 V?
EN-135
Check Yes
Go to step 2.
Go to step 3.
Repair battery
short circuit in
harness between
throttle position
sensor and ECM
connector. After
repair, replace
ECM. <Ref. to
FU-51, Engine
Control Module.>
Engine (Diagnostics)
No
Even if MIL lights
up, the circuit has
returned to a nor-
mal condition at
this time. A tem-
porary poor con-
tact of the con-
nector may be the
cause.
NOTE:
In this case,
repair the follow-
ing:
¼ Poor contact in
throttle position
sensor connector
¼ Poor contact in
ECM connector
¼ Poor contact in
coupling connec-
tor (B21)
Repair harness
and connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
throttle position
sensor and ECM
connector
¼ Poor contact in
coupling connec-
tor (B21)
¼ Poor contact in
joint connector
(B83)
Replace throttle
position sensor.
<Ref. to FU-34,
Throttle Position
Sensor.>