ECU SUBARU FORESTER 2004 Service Repair Manual

EN(H4SO)-189
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AY:DTC P0507 IDLE CONTROL SYSTEM RPM HIGHER THAN EXPECTED
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Engine keeps running at higher revolution than specified idling revolution.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
EN-02396
B137
B135
B134
B21
123
4
56
78
9
1011 12
1314 15 16
EE
B47
E7
2 5
1 4 3 6
B21B61F44
E2
B22
E3
B21
E2
6
4
5
3
2
1
1
2 A6 A20 A19A5
B21 D14A74
1 3
15
16
SBF-5BATTERY MEIN RELAY
IDLE
AIR CONTROL
SOLENOID
VALVE
A:
B134
B:
B135
D:
B137ECM
B47
F44
E7
3412
56
13
4562
B22
125678
131415169101112
34
17181920
7
12345678
4
1
53
2618 15 167891011
17 19
20121314
567
82 1
94
310
24 22 23 251112131415
26 27
281617181920 21
1234567891011121314151617181920212223242526272829303132333435
LHDLHD
RHDRHD
A: B:
D:

EN(H4SO)-191
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AZ:DTC P0512 STARTER REQUEST CIRCUIT
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Failure of engine to start
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.

EN(H4SO)-196
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BB:DTC P0565 CRUISE CONTROL ON SIGNAL
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
EN-02397
B55
22
TCM
B94CCM
3
B94
B55
123410
11 12
19
20 21135614 1578916 17 18
22 23 24
12345678910
11 12 13 14 15 16 17 18 19 20

EN(H4SO)-200
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BD: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 ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.

EN(H4SO)-202
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 radiator fan relay, mea-
sure the 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”. Monitor.>
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):Is the voltage 0 — 10 V? Repair the poor
contact in ECM
connector.Go to step 2.
2 CHECK GROUND SHORT CIRCUIT IN RADI-
ATOR MAIN FAN RELAY CONTROL CIR-
CUIT.
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
(B134) No. 14 — Chassis ground:Is the resistance less than 10
Ω?Repair the ground
short circuit in
radiator main fan
relay control cir-
cuit.Go to step 3.
3 CHECK POWER SUPPLY FOR RELAY.
1) Remove the main 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. 34 (+) — 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 MAIN FAN RELAY.
1) Turn the ignition switch to OFF.
2) Measure the resistance between main fan
relay terminals.
Te r m i n a l s
No. 32 — No. 34:Is the resistance 87 — 107 Ω? Go to step 5.Replace the main
fan relay.
5 CHECK OPEN CIRCUIT IN MAIN FAN RE-
LAY CONTROL CIRCUIT.
Measure the resistance of harness between
ECM and main fan relay connector.
Connector & terminal
(B134) No. 14 — (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 main fan
relay connector
 Poor contact in
coupling connector
6 CHECK POOR CONTACT.
Check poor contact in ECM or main fan relay
connector. Is there poor contact in ECM or
main fan relay connector?Repair the poor
contact in ECM or
main fan relay con-
nector.Contact the SUB-
ARU dealer.

EN(H4SO)-203
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BE: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 ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.

EN(H4SO)-205
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 radiator fan relay, mea-
sure the 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”. Valve Operation Check Mode.>
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):
(B134) No. 13 (+) — Chassis ground (
−):Is the voltage 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 and sub fan
relay. (model with A/C)
3) Disconnect the test mode connectors
4) Turn the ignition switch to ON.
5) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):
(B134) No. 13 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in
radiator fan relay
control circuit.
After repair,
replace the ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>Go to step 3.
3 CHECK MAIN FAN RELAY.
1) Turn the ignition switch to OFF.
2) Remove the main fan relay.
3) Measure the resistance between main fan
relay terminals.
Te r m i n a l s
No. 30 — No. 31:Is the resistance less than 1
Ω?Replace the main
fan relay and
ECM. FU(H4SO)-44,
Engine Control
Module (ECM).>Go to step 4.
4 CHECK SUB FAN RELAY.
1) Remove the sub fan relay.
2) Measure the resistance between sub fan
relay terminals.
Te r m i n a l s
No. 28 — No. 29:Is the resistance less than 1
Ω?Replace the sub
fan relay and
ECM. FU(H4SO)-44,
Engine Control
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(H4SO)-44,
Engine Control
Module (ECM).>

EN(H4SO)-206
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BF:DTC P0703 TORQUE CONVERTER/BRAKE SWITCH “B” CIRCUIT
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
EN-02398
BATTERY
B65
34
12
TO STOP LIGHTS
SBF-1SBF-2No.16
B65 BRAKE
LIGHT
SWITCH
2
3
B64 BRAKE
LIGHT
SWITCH
1
B64
12
B55
B55
12
TCM
2
1
2
2
1
2
1: WITH CRUISE CONTROL
: WITHOUT CRUISE CONTROL
12
789 56 3410 11 12
19 20 2113 14 15 16 17 18
22
23
24

EN(H4SO)-209
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BJ:DTC P0734 GEAR 4 INCORRECT RATIO
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
 Shift point too high or too low.
 Engine brake not effected in 3rd range.
 Excessive shift shock.
 Excessive tight corner braking.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Inspect the rele-
vant DTC using
“List of Diagnostic
Trouble Code
(DTC)”. EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>Go to step 2.
2 CHECK THROTTLE POSITION SENSOR
CIRCUIT.
Check the throttle position sensor circuit. to 4AT(H4SO)-41, DTC 31 THROTTLE POSI-
TION SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>Is there any trouble in throttle
position sensor circuit?Repair or replace
the throttle posi-
tion sensor circuit.Go to step 3.
3 CHECK FRONT VEHICLE SPEED SENSOR
CIRCUIT.
Check front vehicle speed sensor circuit. to 4AT(H4SO)-45, DTC 33 FRONT VEHICLE
SPEED SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>Is there any trouble in front
vehicle speed sensor circuit?Repair or replace
the front vehicle
speed sensor cir-
cuit.Go to step 4.
4 CHECK TORQUE CONVERTER TURBINE
SPEED SENSOR CIRCUIT.
Check torque converter turbine speed sensor
circuit. TORQUE CONVERTER TURBINE SPEED
SENSOR, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>Is there any trouble in torque
converter turbine speed sensor
circuit?Repair or replace
the torque con-
ver ter turbine
speed sensor cir-
cuit.Go to step 5.
5 CHECK POOR CONTACT.
Check poor contact in TCM connector.Is there poor contact in TCM
connector?Repair poor con-
tact in TCM con-
nector.Go to step 6.
6 CHECK MECHANICAL TROUBLE.
Check mechanical trouble in automatic trans-
mission.Is there any mechanical trou-
ble in automatic transmission?Repair or replace
the automatic
transmission.
INSPECTION,
Road Test.>Replace the TCM.
Transmission Con-
trol Module
(TCM).>

EN(H4SO)-210
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BK:DTC P0741 TORQUE CONVERTER CLUTCH CIRCUIT PERFORMANCE OR
STUCK OFF
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
 No lock-up (after engine warm-up)
 No shift or excessive tight corner “braking”
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Inspect the rele-
vant DTC using
“List of Diagnostic
Trouble Code
(DTC)”. EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>Go to step 2.
2 CHECK LOCK-UP DUTY SOLENOID CIR-
CUIT.
Check lock-up duty solenoid circuit. 4AT(H4SO)-74, DTC 77 LOCK-UP DUTY
SOLENOID, Diagnostic Procedure with Diag-
nostic Trouble Code (DTC).>Is there any trouble in lock-up
duty solenoid circuit?Repair or replace
the lock-up duty
solenoid circuit.Go to step 3.
3 CHECK THROTTLE POSITION SENSOR
CIRCUIT.
Check the throttle position sensor circuit. to 4AT(H4SO)-41, DTC 31 THROTTLE POSI-
TION SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>Is there any trouble in throttle
position sensor circuit?Repair or replace
the throttle posi-
tion sensor circuit.Go to step 4.
4 CHECK TORQUE CONVERTER TURBINE
SPEED SENSOR CIRCUIT.
Check torque converter turbine speed sensor
circuit. TORQUE CONVERTER TURBINE SPEED
SENSOR, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>Is there any trouble in torque
converter turbine speed sensor
circuit?Repair or replace
the torque con-
ver ter turbine
speed sensor cir-
cuit.Go to step 5.
5 CHECK ENGINE SPEED INPUT CIRCUIT.
Check engine speed input circuit. 4AT(H4SO)-36, DTC 11 ENGINE SPEED SIG-
NAL, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>Is there any trouble in engine
speed input circuit?Repair or replace
the engine speed
input circuit.Go to step 6.
6 CHECK INHIBITOR SWITCH CIRCUIT.
Check inhibitor switch circuit. 4AT(H4SO)-95, CHECK INHIBITOR SWITCH,
Diagnostic Procedure without Diagnostic Trou-
ble Code (DTC).>Is there any trouble in inhibitor
switch circuit?Repair or replace
the inhibitor switch
circuit.Go to step 7.
7 CHECK BRAKE LIGHT SWITCH CIRCUIT.
Check brake light switch circuit. 4AT(H4SO)-88, CHECK BRAKE SWITCH,
Diagnostic Procedure without Diagnostic Trou-
ble Code (DTC).>Is there any trouble in brake
light switch circuit?Repair or replace
the brake light
switch circuit.Go to step 8.