SUBARU FORESTER 2004 Service Repair Manual

EN(H4DOTC 2.5)-167
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AQ:DTC P0604 INTERNAL CONTROL MODULE READ ACCESS MEMORY
(RAM) ERROR
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
 Engine does not start.
 Engine stalls.
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)-168
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
WIRING DIAGRAM:
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC P0604?Replace the ECM.
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Temporary poor
contact occurs.
EN-02356
B72
B135
3412
BATTERY MAIN RELAY
SBF-4 SBF-1SBF-5
B72
D16 D7
B12
A6
A7
B1
B4
D1
D2
A34B5
B6
B19
D14
No.11
B47
E2 B21 1 2 3 5 6 4
ECM
E
E
1 4
B134
B135
B137 A:
B:
D:
14133
15
16
34 12
56123
4
56
78
91011 12
1314 15 16
B134 B21 B47B137 A: D:
B: IGNITION
SWITCH
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
567
82 1
94 310
24 22 23 2511 12 13 14 15
26 27
2816 17 18 19
20 21
29 30 31 32 33 34 35
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

EN(H4DOTC 2.5)-169
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AR:DTC P0605 INTERNAL CONTROL MODULE READ ONLY MEMORY (ROM)
ERROR
NOTE:
For the diagnostic procedure, refer to DTC P0607. MODULE PERFORMANCE, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

EN(H4DOTC 2.5)-170
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AS:DTC P0607 CONTROL MODULE PERFORMANCE
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
 Erroneous idling
 Poor driving performance
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)-171
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
WIRING DIAGRAM:
EN-02356
B72
B135
3412
BATTERY MAIN RELAY
SBF-4 SBF-1SBF-5
B72
D16 D7
B12
A6
A7
B1
B4
D1
D2
A34B5
B6
B19
D14
No.11
B47
E2 B21 1 2 3 5 6 4
ECM
E
E
1 4
B134
B135
B137 A:
B:
D:
14133
15
16
34 12
56123
4
56
78
91011 12
1314 15 16
B134 B21 B47B137 A: D:
B: IGNITION
SWITCH
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
567
82 1
94 310
24 22 23 2511 12 13 14 15
26 27
2816 17 18 19
20 21
29 30 31 32 33 34 35
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

EN(H4DOTC 2.5)-172
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AT:DTC P0638 THROTTLE ACTUATOR CONTROL RANGE/PERFORMANCE
(BANK 1)
NOTE:
For diagnostic procedure, refer to DTC P2101. TUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
Step Check Yes No
1 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and ground.
Connector & terminal
(B135) No. 5 (+) — Chassis ground (
−):
(B135) No. 6 (+) — Chassis ground (
−):Is the voltage 10 — 13 V? Go to step 2.Repair open or
ground short cir-
cuit of power sup-
ply circuit.
2 CHECK INPUT VOLTAGE OF ECM.
1) Start the engine.
2) Measure the voltage between ECM con-
nector and ground.
Connector & terminal
(B135) No. 5 (+) — Chassis ground (
−):
(B135) No. 6 (+) — Chassis ground (
−):Is the voltage 13 — 15 V? Go to step 3.Repair open or
ground short cir-
cuit of power sup-
ply circuit.
3 CHECK ECM GROUND HARNESS.
Measure the voltage between ECM connector
and ground.
Connector & terminal
(B137) No. 1 (+) — Chassis ground (
−):
(B137) No. 2 (+) — Chassis ground (
−):Is the voltage less than 1 V? Repair the poor
contact in ECM
connector.
Replace the ECM
if defective.Further tighten the
engine ground ter-
minal.

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)-174
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
WIRING DIAGRAM:
EN-02410
No.18
No.17
EE
SBF-4
SBF-1
F17
B135 ECM
25
24F16
F16B72F27
F17
3412
1
2
SUB FAN
MOTOR
M
1
2
MAIN FAN
MOTOR
M
BATTERY
IGNITION
SWITCHB72
41
3132333435
36
56789
1011121314
1516171819
2021222324
2526272829
1230
34
20A
F27 FAN
MODE
RELAY
A/C RELAY HOLDER
MAIN
FAN
RELAY SUB
FAN
RELAY
20A
29
25
27
28
30
34
32
317
5
9
2
1
4
3 8 6
B100F2
12
B135
567
82 1
94 310
24 22 23 2511 12 13 14 15
26 27
2816 17 18 19
20 21
29 30 31 32 33 34 35
7
19
F2
12345 678910
11
1219 20 21
13 14 15 1617
18 22

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.>.