EN(H6DO)-286
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
Value
Yes
No
1
CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to OFF.
2) Connect test mode connector.
3) Turn ignition switch to ON.
4) While operating radiator fan relay, measure
voltage between ECM and chassis ground.
NOTE:
Radiator fan relay operation can be executed
using Subaru Select Monitor. For procedure,
refer to “Compulsory Valve Operation Check
Mode”.<Ref. to EN(H6DO)-55, Compulsory
Valve Operation Check Mode.>
Connector & terminal
(B137) No. 28 (+) — Chassis ground (
−−−−
):
(B137) No. 17 (+) — Chassis ground (
−−−−
):
Does the measured value change within
the specified range?
0 — 10 V
Even if MI lights
up, the circuit has
returned to a nor-
mal condition at
this time. In this
case, repair poor
contact in ECM
connector.
Go to step 2.
2
CHECK SHORT CIRCUIT IN RADIATOR FAN
RELAY CONTROL CIRCUIT.
1) Turn ignition switch to OFF.
2) Remove main fan relay and sub fan relay.
(with A/C models)
3) Disconnect test mode connector.
4) Turn ignition switch to ON.
5) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B137) No. 28 (+) — Chassis ground (
−−−−
):
(B137) No. 17 (+) — Chassis ground (
−−−−
):
Does the measured value exceed the spec-
ified value?
10 V
Repair battery
short circuit in radi-
ator fan relay con-
trol circuit.
Go to step 3.
3
CHECK MAIN FAN RELAY.
1) Turn ignition switch to OFF.
2) Remove main fan relay.
3) Measure resistance between main fan relay
terminals.
Terminal
(F66) No. 5 — No. 7:
(F30) No. 22 — No. 24:
Is the measured value less than the speci-
fied value?
1
Ω
Replace main fan
relay.
Go to step 4.
4
CHECK SUB FAN RELAY.
1) Remove sub fan relay.
2) Measure resistance between sub fan relay
terminals.
Terminal
(F28) No. 25 — No. 27:
(F29) No. 32 — No. 34:
Is the measured value less than the speci-
fied value?
1
Ω
Replace sub fan
relay.
Go to step 5.
5
CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
There is poor contact.
Repair poor con-
tact in ECM con-
nector.
Replace ECM.
<Ref. to
FU(H6DO)-46,
Engine Control
Module.>