Subaru Forester 2004 Service Manual page 147

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTIC)
Step
1 CHECK SPEEDOMETER AND TACHOME-
TER OPERATION IN COMBINATION
METER.
2 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON. (engine
OFF)
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 20 (+) — Chassis ground (
3 CHECK INPUT SIGNAL FOR ECM WITH
SUBARU SELECT MONITOR.
Read the data of fuel level sensor signal using
Subaru Select Monitor.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE". <Ref. to EN(H4DOTC
2.5)-27, Subaru Select Monitor.>
4 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Turn the ignition switch to ON.
4) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B136) No. 20 (+) — Chassis ground (
5 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from connector
(i10), (i11) and ECM connector.
3) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B136) No. 20 — Chassis ground:
6 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
Measure the resistance between ECM and
combination meter connector.
Connector & terminal
(B136) No. 20 — (i11) No. 1:
Check
Does the speedometer and
tachometer operate normally?
Is the voltage less than 0.12
V?
−
):
Does the voltage change by
shaking the ECM harness and
connector?
Is the voltage more than 0.12
V?
−
):
Is the resistance
more than 1 MΩ?
Is the resistance less than 10
Ω?
EN(H4DOTC 2.5)-146
Yes
Go to step 2. Repair or replace
the combination
meter. <Ref. to IDI-
3, Combination
Meter System.>
Go to step 4. Go to step 3.
Repair the poor Even if the mal-
contact in ECM function indicator
connector. light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector
may be the cause.
NOTE:
In this case repair
the following:
• Poor contact in
combination meter
connector
• Poor contact in
ECM connector.
• Poor contact in
coupling connector
Go to step 5. Go to step 6.
Go to step 7. Repair the ground
short in harness
between ECM and
combination meter
connector.
Repair or replace Repair open circuit
the combination between ECM and
meter. <Ref. to IDI- combination meter
3, Combination connector.
Meter System.>
NOTE:
In this case repair
the following:
Poor contact in
coupling connector
No