Subaru 2004 LEGACY Service Manual page 175

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
17 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
(E57) No. 3 — Engine ground:
18 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to ON.
2) Measure the voltage between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 5 (+) — Engine ground (
19 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
Measure the voltage between electronic throt-
tle control connector and engine ground.
Connector & terminal
(E57) No. 6 (+) — Engine ground (
(E57) No. 4 (+) — Engine ground (
20 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Remove the ECM.
3) Measure the resistance between ECM con-
nectors.
Connector & terminal
(B136) No. 18 — (B136) No. 16:
(B136) No. 29 — (B136) No. 16:
21 CHECK SENSOR OUTPUT.
1) Turn the ignition switch to OFF.
2) Connect the connectors except of the elec-
tric throttle control relay.
3) Turn the ignition switch to ON.
4) Read the data of main throttle sensor signal
using Subaru Select Monitor.
22 CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal
using Subaru Select Monitor.
23 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 connector from the elec-
tronic 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:
Check
Is the resistance less than 5
Ω?
Is the voltage less than 10 V?
−
):
Is the voltage less than 10 V?
−
):
−
):
Is the resistance more than 1
MΩ?
Is the voltage 0.81 — 0.87 V? Go to step 22.
Is the voltage 1.64 — 1.70 V? Go to step 23.
Is the resistance less than 1
Ω?
EN(H6DO)(diag)-244
Yes
Go to step 18. Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H6DO)-34,
Engine Control
Module (ECM).>
Go to step 19. Repair the battery
short circuit in har-
ness between
ECM connector
and electronic
throttle control
connector.
Go to step 20. Repair the short
circuit in harness
between ECM
connector and
electronic throttle
control connector.
Go to step 21. Repair the short
circuit to sensor
power supply.
Repair the poor
contact in 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 24. Repair the open
circuit of harness
connector.
No