Subaru Legacy 2005 Service Manual page 1428

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
20 CHECK SENSOR OUTPUT.
1) Turn the ignition switch to OFF.
2) Connect the connectors except for electric
throttle control relay.
3) Turn the ignition switch to ON.
4) Read the data of main throttle sensor signal
using Subaru Select Monitor.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-24, Subaru Select Mon-
itor.>
21 CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal
using Subaru Select Monitor.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-24, Subaru Select Mon-
itor.>
22 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL MO-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from electronic
throttle control.
4) Measure the resistance between ECM con-
nector and electronic throttle control connector.
Connector & terminal
(B137) No. 5 — (E57) No. 2:
(B137) No. 4 — (E57) No. 1:
23 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL MO-
TOR.
1) Connect the connector to ECM.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 2 (+) — Engine ground (
(E57) No. 1 (+) — Engine ground (
24 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL MO-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 2 — Engine ground:
(E57) No. 1 — Engine ground:
25 CHECK ELECTRONIC THROTTLE CON-
TROL MOTOR HARNESS.
Measure the resistance between electronic
throttle control connector terminals.
Connector & terminal
(E57) No. 2 — (E57) No. 1:
Check
Is the voltage 0.81 — 0.87 V? Go to step 21.
Is the voltage 1.64 — 1.70 V? Go to step 22.
Is the resistance less than 1
Ω?
Is the voltage less than 5 V?
−
):
−
):
Is the resistance more than 1
MΩ?
Is the resistance more than 1
MΩ?
EN(H4DOTC)(diag)-188
Yes
Repair the poor
contact of elec-
tronic throttle con-
trol connector.
Replace the elec-
tronic throttle con-
trol if defective.
Repair the poor
contact in ECM
connector.
Replace the elec-
tronic throttle con-
trol if defective.
Go to step 23. Repair the open
circuit of harness
connector.
Go to step 24. Repair the power
supply short cir-
cuit of harness
between ECM and
electronic throttle
control.
Go to step 25. Repair the short
circuit of harness.
Go to step 26. Repair the short
circuit of harness.
No