Subaru LEGACY 2004 Service Manual page 871

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
8 CHECK SHORT CIRCUIT IN ECM.
1) Turn the ignition switch to OFF.
2) Measure the resistance between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 6 — Engine ground:
(E57) No. 4 — Engine ground:
9 CHECK SENSOR OUTPUT.
1) Connect all the connectors.
2) Turn the ignition switch to ON.
3) Read the data of main throttle sensor signal
using Subaru Select Monitor.
10 CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal
using Subaru Select Monitor.
11 CHECK POOR CONTACT.
Check poor contact in connector between
ECM and electronic throttle control.
12 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 & terminal
(B136) No. 35 — (E57) No. 3:
(B136) No. 18 — (E57) No. 6:
(B136) No. 29 — (E57) No. 4:
13 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:
14 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
(E57) No. 5 (+) — Engine ground (
15 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 (
Check
Is the resistance more than 10
Ω?
Is the voltage less than 4.63
V?
Is the voltage less than 4.73
V?
Is there poor contact?
Is the resistance less than 1
Ω?
Is the resistance less than 5
Ω?
Is the voltage less than 10 V?
−
):
Is the voltage less than 10 V?
−
):
−
):
EN(H4SO 2.5)(diag)-255
ENGINE (DIAGNOSTICS)
Yes
Go to step 9. Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.5)-
36, Engine Con-
trol Module
(ECM).>
Go to step 10. Go to step 12.
Go to step 11. Go to step 12.
Repair the poor Temporary poor
contact. contact occurred,
but it is normal at
present.
Go to step 13. Repair the open
circuit of harness
connector.
Go to step 14. Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.5)-
36, Engine Con-
trol Module
(ECM).>
Go to step 15. Repair the battery
short circuit in har-
ness between
ECM connector
and electronic
throttle control
connector.
Go to step 16. Repair the short
circuit in harness
between ECM
connector and
electronic throttle
control connector.
No