Subaru Legacy 2004 Service Manual page 651

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
10 CHECK POOR CONTACT.
Check poor contact in connector between
ECM and electronic throttle control.
11 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
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 & terminals
(B137) No. 23 — (E78) No. 5:
(B137) No. 24 — (E78) No. 2:
(B136) No. 17 — (E78) No. 4:
12 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Connect the ECM connector.
2) Measure the resistance between electronic
throttle control connector and engine ground.
Connector & terminal
(E78) No. 1 — Engine ground:
13 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Connect the ECM connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic
throttle control connector and engine ground.
Connector & terminal
(E78) No. 4 (+) — Engine ground (
14 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
Measure the voltage between electronic throt-
tle control connector and engine ground.
Connector & terminal
(E78) No. 5 (+) — Engine ground (
(E78) No. 2 (+) — Engine ground (
15 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between ECM con-
nectors.
Connector & terminal
(B137) No. 23 — (B136) No. 17:
(B137) No. 24 — (B136) No. 17:
16 CHECK ELECTRONIC THROTTLE CON-
TROL HARNESS.
1) Disconnect the connector from ECM.
2) Disconnect the connectors from electronic
throttle control.
3) Measure the resistance between electronic
throttle control connector terminals.
Connector & terminal
(E78) No. 5 — (E78) No. 2:
Check
Is there poor contact?
Is the resistance less than 1
&?
Is the resistance less than 5
&?
Is the voltage less than 10 V?
"
):
Is the voltage less than 10 V?
"
):
"
):
Is the resistance more than 1
M&?
Is the resistance more than 1
M&?
EN(H4SO 2.0)(diag)-219
ENGINE (DIAGNOSTICS)
Yes
Repair the poor Temporary poor
contact. contact occurred,
but it is normal at
present.
Go to step 12. Repair the open
circuit of harness
connector.
Go to step 13. Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.0)-
34, Engine Con-
trol Module
(ECM).>
Go to step 14. Repair the battery
short circuit in har-
ness between
ECM connector
and electronic
throttle control
connector.
Go to step 15. Repair the short
circuit in harness
between ECM
connector and
electronic throttle
control connector.
Go to step 16. Repair the short
circuit to sensor
power supply.
Repair the poor Repair the short
contact in ECM circuit of harness.
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.0)-
34, Engine Con-
trol Module
(ECM).>
No