Subaru Forester 2004 Service Manual page 230

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
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. 35:
(B136) No. 29 — (B136) No. 35:
21 CHECK SENSOR OUTPUT.
1) Turn the ignition switch to OFF.
2) Connect the connectors except of the elec-
tric control throttle 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 connectors from the elec-
tronic throttle control.
4) Measure the resistance between ECM con-
nector and electronic throttle control connector.
Connector & terminal
(B137) No. 4 — (E57) No. 1:
(B137) No. 5 — (E57) No. 2:
24 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. 1 (+) — Engine ground (
(E57) No. 2 (+) — Engine ground (
25 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. 1 — Engine ground:
(E57) No. 2 — Engine ground:
26 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 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?
Is the voltage less than 5 V?
−
):
−
):
Is the resistance more than 1
MΩ?
Is the resistance more than 1
MΩ?
EN(H4DOTC 2.5)-229
ENGINE (DIAGNOSTIC)
Yes
Go to step 21. Repair short circuit
to sensor power
supply.
Repair poor contact
of electronic throt-
tle control connec-
tor. Replace the
electronic throttle
control if defective.
Repair the poor
contact in ECM con-
nector. Replace the
electronic throttle
control if defective.
Go to step 24. Repair the open
circuit of harness
connector.
Go to step 25. Repair power sup-
ply short circuit in
harness between
ECM and electronic
throttle control.
Go to step 26. Repair the short
circuit of harness.
Go to step 27. Repair the short
circuit of harness.
No