Subaru IMPREZA 2004 Service Manual page 41

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
6 CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connectors from throttle posi-
tion sensor.
3)Turn the ignition switch to ON.
4)Measure the voltage between throttle posi-
tion sensor connector and engine ground.
Connector & terminal
(E13) No. 4 (+) — Engine ground ( − − − − ):
7 CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
1)Turn the ignition switch to OFF.
2)Measure the resistance of harness between
ECM connector and throttle position sensor
connector.
Connector & terminal
(B135) No. 13 — (E13) No. 3:
8 CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
Measure the resistance of harness between
throttle position sensor connector and engine
ground.
Connector & terminal
(E13) No. 3 — Engine ground:
9 CHECK POOR CONTACT.
Check poor contact in throttle position sensor
connector.
Check
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?
Is there poor contact in throttle
position sensor connector?
EN(H4SO)(diag)-118
Yes
Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
throttle position
sensor and ECM
connector
• Poor contact in
throttle position
sensor connector
• Poor contact in
ECM connector
• Poor contact in
coupling connector
• Poor contact in
joint connector
Go to step 8. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
throttle position
sensor and ECM
connector
• Poor contact in
ECM connector
• Poor contact in
throttle position
sensor connector
• Poor contact in
coupling connector
Go to step 9. Repair ground
short circuit in har-
ness between
throttle position
sensor and ECM
connector.
Repair poor con- Replace the throt-
tact in throttle posi- tle position sen-
tion sensor sor. <Ref. to
connector. FU(H4SO)-31,
Throttle Position
Sensor.>
No