Subaru Legacy 2005 Service Manual page 1399

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK TRANSMISSION TYPE.
2 CHECK DTC.
Check the DTC of AT.
3 CHECK HARNESS BETWEEN ECM AND
TCM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
TCM.
3) Measure the resistance of harness
between ECM and TCM.
Connector & terminal
(B137) No. 9 — (B55) No. 19:
4 CHECK HARNESS BETWEEN ECM AND
TCM.
Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B137) No. 9 — Chassis ground:
5 CHECK INPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Place the shift lever in neutral.
3) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 9 (+) — Chassis ground (
6 CHECK INPUT SIGNAL OF ECM.
1) Place the shift lever except in neutral.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 9 (+) — Chassis ground (
7 CHECK NEUTRAL POSITION SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion harness.
3) Place the shift lever in neutral.
4) Measure the resistance between transmis-
sion harness and connector terminals.
Connector & terminal
(T2) No. 1 — No. 3:
8 CHECK NEUTRAL POSITION SWITCH.
1) Place the shift lever except in neutral.
2) Measure the resistance between transmis-
sion harness connector terminals.
9 CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B137) No. 9 — Chassis ground:
Check
Is the transmission type AT?
Is DTC of AT displayed?
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the voltage more than 10 V? Go to step 6.
−
):
Is the voltage less than 1 V?
−
):
Is the resistance more than 1
MΩ?
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
EN(H4DOTC)(diag)-159
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Go to step 5.
Perform the diag- Go to step 3.
nosis for AT. <Ref.
to 5AT(diag)-35,
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>
Go to step 4. Repair the open
circuit of harness
between ECM and
TCM.
Repair the poor Repair the ground
contact in ECM short circuit of har-
and TCM connec- ness between
tor. ECM and TCM.
Go to step 7.
Repair the poor Go to step 7.
contact in ECM
connector.
Go to step 8. Repair the short
circuit in transmis-
sion harness, or
replace the neu-
tral position switch.
Go to step 9. Repair the short
circuit in transmis-
sion harness, or
replace the neu-
tral position switch.
Go to step 10. Repair the ground
short circuit of har-
ness between
ECM and trans-
mission harness
connector.
No