Main Relay SUBARU FORESTER 1999 Service Repair Manual

3. CHECK CRUISE CONTROL MAIN SWITCH
DIAGNOSIS:
IFaulty cruise control main switch, or open harness.
TROUBLE SYMPTOM:
ICruise control main switch is not turned ON and cruise control cannot be set.
NOTE:
When the main relay (built-in cruise control module) operates, the main switch circuit is in normal condi-
tion.
The main relay operation can be checked by hearing the operation sounds.
This operation sounds will be heard when ignition switch and cruise control main switch is turned to ON.
WIRING DIAGRAM:
S6M0108
26
6-2[T3G3]DIAGNOSTICS
3. Cruise Control System

3G31 : CHECK FUSE.
Check fuse No. 18.
S6M0110A
:Is fuse No. 18 blown?
: Replace fuse No. 18. Go to step3G32.
: Go to step3G32.
3G32 : CHECK POWER SUPPLY.
1) Turn ignition switch to ON.
2) Measure voltage between fuse & relay box con-
nector and chassis ground.
Connector & terminal
(B152) No. 5 (+) Ð Chassis ground (þ):
:Is voltage more than 10 V?
: Go to step3G33.
: Replace fuse No. 18. When fuse No. 18
is blown again, repair shorted parts of
circuit.3G33 : CHECK CRUISE CONTROL MAIN
SWITCH.
1) Turn ignition switch to OFF.
2) Remove cruise control main switch and discon-
nect connector.
3) Turn ignition switch to ON.
4) Measure voltage between cruise control main
switch connector and chassis ground.
Connector & terminal
(B161) No. 3 (+) Ð Chassis ground (þ):
B6M0183C
:Is voltage more than 10 V?
: Go to step3G34.
: Replace cruise control main switch.

3G34 : CHECK CRUISE CONTROL MAIN
SWITCH.
Measure resistance between cruise control main
switch terminals.
Terminals
No. 3 Ð No. 5:
G6M0244
:Is resistance less than 10W? (When
switch is ON.)
: Go to step3G35.
: Replace cruise control main switch.

27
[T3G3]6-2DIAGNOSTICS
3. Cruise Control System

3H51 : CHECK POWER SUPPLY.
1) Turn ignition switch to ON.
2) Turn cruise control main switch to ON.
3) Set select monitor in ªCurrent Data Display &
Saveº mode.
4) Check signals for proper operation.
(1) When pushing the SET/COAST switch:
The SET/COAST switch shown on the display
turns from ªOFFº to ªONº.
(2) When pushing the RESUME/ACCEL
switch:
The RESUME/ACCEL switch shown on the dis-
play turns from ªOFFº to ªONº.
5) Turn ignition switch to OFF.
6) Disconnect connector from cruise control com-
mand switch.
7) Turn ignition switch to ON.
8) Measure voltage between cruise control com-
mand switch connector and chassis ground.
Terminals
No. 1 (+) Ð Chassis ground (þ):
S6M0124
:Is voltage more than 10 V?
: Go to step3H52.
: Repair or replace wiring harness
between fuse & relay box and cruise
control command switch. [W12B3].>3H52 : CHECK CRUISE CONTROL COM-
MAND SWITCH.
1) Turn ignition switch to OFF.
2) Connect connector of cruise control command
switch.
3) Turn ignition switch to ON.
4) Measure voltage between cruise control com-
mand switch connector and chassis ground.
Terminals
No. 2 (+) Ð Chassis ground (þ):
S6M0124
:Is voltage more than 10 V? (When
SET/COAST switch is ON.)
: Go to step3H53.
: Replace cruise control command
switch.
3H53 : CHECK CRUISE CONTROL COM-
MAND SWITCH.
Measure voltage between cruise control command
switch connector and chassis ground.
Terminals
No. 3 (+) Ð Chassis ground (þ):
S6M0124
:Is voltage more than 10 V? (When
RESUME/ACCEL switch is ON.)
: Go to step3H54.
: Replace cruise control command
switch.
43
[T3H5]6-2DIAGNOSTICS
3. Cruise Control System

7. DIAGNOSTIC CODE 25 (CRUISE
CONTROL MODULE BUILT-IN RELAY,
CPU RAM)
DIAGNOSIS:
IPoor welding of built-in relay of cruise control
module.
IFailure of built-in CPU RAM of cruise control
module.
TROUBLE SYMPTOM:
ICruise control is canceled and memorized
cruise speed is also canceled.
IOnce cruise control is canceled, cruise control
cannot be set until the ignition switch and cruise
control main switch turns OFF, and then turns ON
again.
NOTE:
Check input/output signal and vehicle speed signal
with select monitor. When signals are in good
condition, failure is in cruise control module.
(Check power supply and ground conditions of
cruise control module.)
I: DIAGNOSTICS CHART WITH
SELECT MONITOR
1. FUNCTION MODE
NOTE:
Select monitor part No.:

Select the ªCruise Controlº system using the select
monitor and set the ªCurrent Data Display & Saveº
mode. The following parameters will then appear
on the display.
IVehicle Speed
The current vehicle speed is shown on the display.
IStop Light Switch
When the brake pedal is depressed, the stop light
switch shown on the display turns from ªOFFº to
ªONº.
IBrake Switch
When the brake pedal is depressed, the brake
switch shown on the display turns from ªOFFº to
ªONº.
IªSET/COASTº Switch
When the cruise control command switch is placed
in the ªSET/COASTº position, the SET/COAST
switch shown on the display turns from ªOFFº to
ªONº.
IªRESUME/ACCELº Switch
When the cruise control command switch is placed
in the ªRESUME/ACCELº position, the RESUME/
ACCEL switch shown on the display turns from
ªOFFº to ªONº.
IClutch/Inhibitor SwitchWhen the clutch pedal is depressed, the clutch/
inhibitor switch shown on the display turns from
ªONº to ªOFFº. (MT)
When the select lever is moved from the ªNº or ªPº
position to any other position, the clutch/inhibitor
switch shown on the display turns from ªONº to
ªOFFº.
52
6-2[T3H7]DIAGNOSTICS
3. Cruise Control System

C: ELECTRICAL COMPONENTS LOCATION
S6M0450A
(1) Horn
(2) Keyless entry control module(3) Horn relay (in main fuse box)
(4) Rear gate latch switch(5) Door switch
57
[T4C0]6-2DIAGNOSTICS
4. Keyless Entry System

2. DIAGNOSTICS ITEM 1
4F21 : SELECT HORN SIGNAL OPERA-
TION.
Keep both LOCK/ARM and UNLOCK/DISARM
buttons pressed for more than 1.5 seconds.
:Does the horn chirp one time?
: Go to step4F22.
: Replace keyless entry control module.

4F22 : CHECK HORN SIGNAL OUTPUT
SIGNAL.
1) Disconnect connector from keyless entry con-
trol module.
2) Measure voltage between keyless entry control
module connector (B176) and chassis ground.
Connector & terminal
(B176) No. 12 (+) Ð Chassis ground (þ):
B6M0958A
:Is the voltage more than 10 V?
: Go to step4F23.
: Go to step4F26.4F23 : CHECK HORN RELAY.
1) Remove horn relay from main fuse box.
2) Check continuity between horn relay terminals.
Terminals
No. 1 Ð No. 2:
B6M1348B
:Does continuity exist?
: Replace horn relay.
: Go to step4F24.
4F24 : CHECK HORN RELAY.
Check continuity between horn relay terminals.
Terminals
No. 3 Ð No. 4:
B6M1349B
:Does continuity exist?
: Go to step4F25.
: Replace horn relay.
63
[T4F2]6-2DIAGNOSTICS
4. Keyless Entry System

4F25 : CHECK HORN RELAY.
1) Connect the battery to horn relay terminals No.
3 and No. 4.
2) Check continuity between horn relay terminals.
Terminals
No. 1 Ð No. 2:
B6M1350B
:Does continuity exist?
: Repair wiring harness of horn circuit.
: Replace horn relay.
4F26 : CHECK FUSE.
Remove and visually check the fuse No. 6 (in main
fuse box).
:Is the fuse No. 6 blown?
: Replace fuse (15 A).
: Go to step4F27.4F27 : CHECK POWER SUPPLY FOR
HORN RELAY.
1) Install horn relay to main fuse box.
2) Measure voltage between main fuse box con-
nector (F37) and chassis ground.
Connector & terminal
(F37) No. 4 (+) Ð Chassis ground (þ):
B6M1351A
:Is the voltage more than 10 V?
: Go to step4F28.
: Repair wiring harness between main
fuse box and battery.
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6-2[T4F2]DIAGNOSTICS
4. Keyless Entry System

4F28 : CHECK RESISTANCE BETWEEN
HORN RELAY AND KEYLESS
ENTRY CONTROL MODULE.
1) Disconnect connector from main fuse box and
keyless entry control module.
2) Measure resistance between keyless entry con-
trol module connector (B176) and main fuse box
connector (F37).
Connector & terminal
(B176) No. 12 Ð (F37) No. 4:
B6M1352A
:Is the resistance less than 10W?
: Replace keyless entry control module.

: Repair wiring harness between main
fuse box and keyless entry control mod-
ule.
3. DIAGNOSTICS ITEM 2
4F31 : CHECK FUSE.
Remove and visually check the fuse No. 2 (in main
fuse box).
:Is fuse No. 2 blown?
: Replace fuse (15 A).
: Go to step4F32.
4F32 : CHECK ROOM LIGHT BULB.
Remove and visually check the room light bulb.
:Is the bulb blown?
: Replace bulb.
: Go to step4F33.
4F33 : CHECK ROOM LIGHT SWITCH.
1) Remove room light.
2) Measure resistance of room light switch termi-
nal at the middle position.
Terminals
No. 2 Ð No. 3:
B6M0960A
:Is the resistance less than 1W?
: Repair or replace room light.
: Go to step4F34.
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[T4F3]6-2DIAGNOSTICS
4. Keyless Entry System

C: ELECTRICAL COMPONENTS LOCATION
S6M0454A
(1) Horn
(2) Keyless entry control module
(3) Security control module (under
console box)
(4) Security indicator light (in combi-
nation meter)(5) Horn relay (in main fuse box)
(6) Rear gate latch switch
(7) Interrupt relay (behind the fuse
box)
(8) Door switch(9) Passive arm connector (on driver
side front lower pillar)
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[T5C0]6-2DIAGNOSTICS
5. Security System

5. DIAGNOSTICS ITEM 4
5F51 : CHECK INPUT SIGNAL FOR
STARTER MOTOR.
1) Disconnect connector from starter motor.
2) Turn ignition switch to START.
3) Measure voltage between starter motor con-
nector (B14) and engine ground.
Connector & terminal
(B14) No. 1 (+) Ð Engine ground (þ):
OBD0100A
NOTE:
IOn AT vehicles, place the select lever in the P
or N position.
IOn MT vehicles, depress the clutch pedal.
:Is the voltage more than 10 V?
: Go to step5F52.
: Go to step5F53.
5F52 : CHECK GROUND CIRCUIT OF
STARTER MOTOR.
1) Turn ignition switch to OFF.
2) Disconnect terminal from starter motor.
3) Measure resistance between ground cable ter-
minal and engine ground.
:Is the resistance less than 5W?
: Check starter motor. [W100].>
: Repair or replace ground cable.
5F53 : CHECK FUSE.
Remove and visually check the fuse SBF-1 (in
main fuse box).
:Is fuse SBF-1 blown?
: Replace SBF fuse (80 A).
: Go to step5F54.5F54 : CHECK FUSE.
Remove and visually check the fuse SBF-4 (in
main fuse box).
:Is fuse SBF-4 blown?
: Replace SBF fuse (50 A).
: Go to step5F55.
5F55 : CHECK INTERRUPT RELAY.
1) Turn ignition switch to OFF.
2) Remove interrupt relay (behind the fuse box).
S6M0469
3) Check continuity between interrupt relay termi-
nals.
Terminals
No. 1 Ð No. 4:
B6M0992
:Does continuity exist?
: Go to step5F56.
: Replace interrupt relay.
84
6-2[T5F5]DIAGNOSTICS
5. Security System