ECU SUBARU FORESTER 2004 Service Repair Manual

EN(H4DOTC 2.5)-141
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AF:DTC P0458 EVAPORATIVE EMISSION CONTROL SYSTEM PURGE CON-
TROL VALVE CIRCUIT LOW
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Erroneous idling
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
WIRING DIAGRAM:
EN-02366
B47 1 2 3 5 4 6
E
B21
E2B47
B134
B134
E4 ECM
14 2 1
SBF-534 12
56
2 1
123
4
56
78
9
1011 12
1314 15 16
E4 B21
12
56 7
82 1
94 310
24 22 23 25 11 12 13 14 15
26 27
2816 17
18 19 20 21
33 34 29
32 30 31
MAIN RELAY
BATTERY
PURGE CONTROL
SOLENOID VALVE

EN(H4DOTC 2.5)-143
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AG:DTC P0459 EVAPORATIVE EMISSION CONTROL SYSTEM PURGE CON-
TROL VALVE CIRCUIT HIGH
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Erroneous idling
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
WIRING DIAGRAM:
EN-02366
B47 1 2 3 5 4 6
E
B21
E2B47
B134
B134
E4 ECM
14 2 1
SBF-534 12
56
2 1
123
4
56
78
9
1011 12
1314 15 16
E4 B21
12
56 7
82 1
94 310
24 22 23 25 11 12 13 14 15
26 27
2816 17
18 19 20 21
33 34 29
32 30 31
MAIN RELAY
BATTERY
PURGE CONTROL
SOLENOID VALVE

EN(H4DOTC 2.5)-144
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector at the lower
portion of instrument panel (on the driver’s side).
3) Turn the ignition switch to ON.
4) While operating the purge control solenoid
valve, measure voltage between ECM and
chassis ground.
N
OTE:
Purge control solenoid valve operation can be
executed using Subaru Select Monitor. For the
procedure, refer to “Compulsory Valve Opera-
tion Check Mode”. 43, Compulsory Valve Operation Check
Mode.>
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):Is the voltage 0 — 13 V? Go to step 2.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. In this
case, repair poor
contact in ECM
connector.
2 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 4.Go to step 3.
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Replace the ECM.
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
4 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from purge con-
trol solenoid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
After repair,
replace the ECM.
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Go to step 5.
5 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Turn the ignition switch to OFF.
2) Measure the resistance between purge
control solenoid valve terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance less than 1
Ω?Replace the purge
control solenoid
valve and ECM.
EC(H4DOTC)-7,
Purge Control
Solenoid Valve.>
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Go to step 6.
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Replace the ECM.
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>

EN(H4DOTC 2.5)-145
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AH:DTC P0462 FUEL LEVEL SENSOR CIRCUIT LOW INPUT
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
WIRING DIAGRAM:
EN-02367
B72
R59 R58B21
B136
i11
1
2345678910
R15 B136
ECM No.14
i10
B38
B21 E2
B98
R2 i3 B38
i3
E E E
FUEL
GAUGE
B:
i11 C: SBF-4 SBF-1
B721 4
B9 B10
C1
3
17
R15
R59R572 1
2
R583
53
16 20
12 1 3
4562123
4
56
78
9
1011 12
1314 15 16
C:
56
782 1
94 310
24 22 23 2511 12 13
1415
26 27
2816
17 18 19 20 21
33 34 29
32 30
31 35
2 20
16
BATTERY
IGNITION SWITCH
COMBINATION
METER
FUEL SUB
LEVEL SENSORFUEL
LEVEL SENSOR
3412
123456789101112131415161718192021222324252627282930
i10 B:
B38i3
3412
B98
219
32
1234
5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25

EN(H4DOTC 2.5)-148
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AI: DTC P0463 FUEL LEVEL SENSOR CIRCUIT HIGH INPUT
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
WIRING DIAGRAM:
EN-02367
B72
R59 R58B21
B136
i11
1
2345678910
R15 B136
ECM No.14
i10
B38
B21 E2
B98
R2 i3 B38
i3
E E E
FUEL
GAUGE
B:
i11 C: SBF-4 SBF-1
B721 4
B9 B10
C1
3
17
R15
R59R572 1
2
R583
53
16 20
12 1 3
4562123
4
56
78
9
1011 12
1314 15 16
C:
56
782 1
94 310
24 22 23 2511 12 13
1415
26 27
2816
17 18 19 20 21
33 34 29
32 30
31 35
2 20
16
BATTERY
IGNITION SWITCH
COMBINATION
METER
FUEL SUB
LEVEL SENSORFUEL
LEVEL SENSOR
3412
123456789101112131415161718192021222324252627282930
i10 B:
B38i3
3412
B98
219
32
1234
5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25

EN(H4DOTC 2.5)-173
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AU:DTC P0691 COOLING FAN 1 CONTROL CIRCUIT LOW
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
 Radiator fan does not operate properly.
 Over-heating
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.

EN(H4DOTC 2.5)-175
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector.
3) Turn the ignition switch to ON.
4) While operating the radiator fan relay, mea-
sure voltage between ECM terminal and ground.
N
OTE:
Radiator fan relay operation can be executed
using Subaru Select Monitor. For procedure,
refer to “Compulsory Valve Operation Check
Mode”. Select Monitor.>
Connector & terminal
(B135) No. 24 (+) — Chassis ground (
−):
(B135) No. 25 (+) — Chassis ground (
−):Does the voltage vary between
0 — 10 V?Repair the poor
contact in ECM
connector.Go to step 2.
2 CHECK GROUND SHORT CIRCUIT IN RADI-
ATOR FAN RELAY CONTROL CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B135) No. 24 — Chassis ground:
(B135) No. 25 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground
short circuit in
radiator fan relay
control circuit.
3 CHECK POWER SUPPLY FOR RELAY.
1) Remove the main fan relay and sub fan relay
from A/C relay holder.
2) Turn the ignition switch to ON.
3) Measure the voltage between fuse and
relay box (F/B) connector and chassis ground.
Connector & terminal
(F27) No. 27 (+) — Chassis ground (
−):
(F27) No. 32 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 4.Repair open circuit
in harness
between ignition
switch and fuse
and relay box (F/B)
connector.
4 CHECK FAN RELAY.
1) Turn the ignition switch to OFF.
2) Measure the resistance between fan relay
terminals.
Te r m i n a l s
No. 32 — No. 34 (Main fan relay)
No. 25 — No. 27 (Sub fan relay)Is the resistance 87 — 107 Ω? Go to step 5.Replace the fan
relay.
5 CHECK OPEN CIRCUIT IN FAN RELAY
CONTROL CIRCUIT.
Measure the resistance of harness between
ECM and fan relay connector.
Connector & terminal
(B135) No. 24 — (F27) No. 27:
(B135) No. 25 — (F27) No. 32:Is the resistance less than 1
Ω?Go to step 6.Repair harness
and connector.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and fan relay
connector
 Poor contact in
coupling connector
6 CHECK POOR CONTACT.
Check poor contact in ECM or fan relay connector.Is there poor contact in ECM or
fan relay connector?Repair the poor
contact in ECM or
fan relay connector.Contact the SUB-
ARU dealer.

EN(H4DOTC 2.5)-176
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AV:DTC P0692 COOLING FAN 1 CONTROL CIRCUIT HIGH
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
 Radiator fan does not operate properly.
 Over-heating
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.

EN(H4DOTC 2.5)-178
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AW:DTC P0700 TRANSMISSION CONTROL SYSTEM (MIL REQUEST)
NOTE:
For the diagnostic procedure, refer to AT section. Procedure.>
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector.
3) Turn the ignition switch to ON.
4) While operating the radiator fan relay, mea-
sure voltage between ECM and chassis ground.
N
OTE:
Radiator fan relay operation can be executed
using Subaru Select Monitor. For procedure,
refer to “Compulsory Valve Operation Check
Mode”. sory Valve Operation Check Mode.>
Connector & terminal
(B135) No. 24 (+) — Chassis ground (
−):
(B135) No. 25 (+) — Chassis ground (
−):Does the voltage vary between
0 — 10 V?Even if the mal-
function indicator
light illuminates,
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 the ignition switch to OFF.
2) Remove the main fan relay, sub fan relay
and fan mode relay.
3) Disconnect the test mode connectors
4) Turn the ignition switch to ON.
5) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B135) No. 24 (+) — Chassis ground (
−):
(B135) No. 25 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in radi-
ator fan relay con-
trol circuit. After
repair, replace the
ECM. FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Go to step 3.
3 CHECK FAN RELAY.
1) Turn the ignition switch to OFF.
2) Remove the fan relay.
3) Measure the resistance between fan relay
terminals.
Te r m i n a l s
No. 30 — No. 31 (Main fan relay)
No. 28 — No. 29 (Sub fan relay)Is the resistance less than 1
Ω?Replace the fan
relay and ECM.
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Go to step 4.
4 CHECK FAN MODE RELAY.
1) Remove the fan mode relay.
2) Measure the resistance between fan mode
relay terminals.
Te r m i n a l s
No. 8 — No. 9: (Fan mode relay)Is the resistance less than 1
Ω?Replace the fan
mode relay and
ECM. FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Go to step 5.
5 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Replace the ECM.
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>

EN(H4DOTC 2.5)-179
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AX:DTC P0851 NEUTRAL SWITCH INPUT CIRCUIT LOW (AT MODEL)
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Erroneous idling.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
WIRING DIAGRAM:
EN-02370
B12T3
B14
T7
PRND321
12
7
12
11
B12
T7
123456789101112
123
4
56
78
9
1011 12
B137
9
16
E2
E
B21
B21
12345678910111213141516
B128
T91
3B128
T9
B128
1
43 2
M
B137
MT
AT
567
82 1
94 310
22 23 11 12 13 14 15
24 25
2616 17
18 19 20 21
27 28 29 30 31
INHIBITOR SWITCH
STARTER MOTOR ECM
NEUTRAL
POSITION
SWITCH