Subaru Impreza 2004 Service Manual page 187

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
6 CHECK HARNESS BETWEEN ECM AND
TUMBLE GENERATOR VALVE POSITION
SENSOR CONNECTOR.
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
(E54) No. 1 (+) — Engine ground ( − − − − ):
7 CHECK HARNESS BETWEEN ECM AND
TUMBLE GENERATOR VALVE POSITION
SENSOR CONNECTOR.
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. 23 — (E54) No. 3:
8 CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
Measure the resistance of harness between
tumble generator valve position sensor con-
nector and engine ground.
Connector & terminal
(E54) No. 3 — Engine ground:
9 CHECK POOR CONTACT.
Check poor contact in tumble generator valve
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 tumble
generator valve position sensor
connector?
EN(H4DOTC)(diag)-266
Yes
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
tumble generator
valve position sen-
sor and ECM con-
nector
• 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 the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
tumble generator
valve position sen-
sor and ECM con-
nector
• Poor contact in
ECM connector
• Poor contact in
tumble generator
valve position sen-
sor connector
• Poor contact in
coupling connector
Go to step 9. Repair the ground
short circuit in har-
ness between tum-
ble generator valve
position sensor
and ECM connec-
tor.
Repair the poor Replace the tum-
contact in tumble ble generator valve
generator valve assembly. <Ref. to
position sensor FU(H4DOTC)-41,
connector. Tumble Generator
Valve Assembly.>
No