Subaru Forester 2004 Service Manual page 253

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTIC)
Step
14 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Measure the voltage between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 4 (+) — Engine ground (
(E57) No. 6 (+) — Engine ground (
2) Check the voltage change by shaking the
harness and connector of ECM and engine
harness connector while monitoring the value
with voltage meter.
15 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the ECM connector.
3) Measure the resistance between ECM con-
nectors.
Connector & terminal
(B136) No. 18 — (B136) No. 35:
(B136) No. 29 — (B136) No. 35:
16 CHECK ELECTRONIC THROTTLE CON-
TROL HARNESS.
1) Disconnect the connector from ECM.
2) Disconnect the connectors from the elec-
tronic throttle control.
3) Measure the resistance between electronic
throttle control connector terminals.
Connector & terminal
(E57) No. 6 — (E57) No. 4:
Check
Is the voltage less than 10 V?
−
):
−
):
Is the resistance more than 1
MΩ?
Is the resistance more than 1
MΩ?
EN(H4DOTC 2.5)-252
Yes
Go to step 15. Repair short circuit
in harness between
ECM connector and
electronic throttle
control connector.
Go to step 16. Repair short circuit
to sensor power
supply.
Repair the poor Repair the short
contact in ECM con- circuit of harness.
nector. Replace the
ECM if defective.
No