Subaru Legacy 2002 Service Manual page 1502

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 20 (+) — Chassis ground
(−):
2 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
Measure voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 20 (+) — Chassis ground
(−):
3 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
Measure voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 20 (+) — Chassis ground
(−):
4 CHECK OUTPUT SIGNAL FROM ECM.
Measure voltage between ECM and chassis
ground.
Connector & terminal
(B135) No. 20 (+) — Chassis ground
(−):
5 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
Measure voltage between TCM and chassis
ground.
Connector & terminal
(B54) No. 20 (+) — Chassis ground (−):
6 CHECK POOR CONTACT.
Check poor contact in TCM connector.
Step
Is the voltage more than 10
V?
Is the voltage more than 4
V?
Is the voltage less than 1
V?
Does the voltage change
from 1 V to 4 V while moni-
toring the value with volt-
age meter?
Is the voltage more than 4
V?
Is there poor contact in
TCM connector?
EN(H6)-295
Check Yes
Repair battery
short circuit in
harness between
ECM and TCM
connector.
Go to step 5.
Repair poor con-
tact in ECM con-
nector.
Even if MIL lights
up, the circuit has
returned to a nor-
mal condition at
this time.
NOTE:
In this case,
repair the follow-
ing:
¼ Poor contact in
ECM connector
¼ Poor contact in
TCM connector
Go to step 6.
Repair poor con-
tact in TCM con-
nector.
Engine (DIAGNOSTICS)
No
Go to step 2.
Go to step 3.
Go to step 4.
Contact with your
Subaru distributor
service.
NOTE:
Inspection by
DTM is required,
because probable
cause is deterio-
ration of multiple
parts.
Repair open cir-
cuit in harness
between ECM
and TCM connec-
tor.
Check TCM
power supply line
and grounding
line.