engine SUBARU LEGACY 1997 Service Repair Manual

5. Control Module I/O Signal
G6M0015
ContentTerminal
No.Measuring conditions and I/O signals (ignition switch ON and engine idling)
Main power supply 2
Battery voltage is present when main power is turned ON.

“0”volt is present when main power is turned OFF.
Inhibitor switch (AT) (U.S.A.)
N position switch (AT) (CANADA)4
“0”volt is present when selector lever is set to P or N position (CANADA: N position only).

Battery voltage is present when selector lever is other than P or N position (CANADA: N
position only).
Air valve 5
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
GND 6—
Vacuum pump motor 7
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
Data link connector 8—
RESUME/ACCEL switch 9
Battery voltage is present when switch is turned ON.

“0”volt is present when switch is turned OFF.
SET/COAST switch 10
Battery voltage is present when switch is turned ON.

“0”volt is present when switch is turned OFF.
Ignition switch 12
Battery voltage is present when ignition switch is turned ON.

“0”volt is present when ignition switch is turned OFF.
Release valve 13
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
Power supply to vacuum pump
motor, air valve, release valve14
“0”volt is present when vehicle is stopped.

Battery voltage is present while cruise control is operating.
Cruise main switch 15
Battery voltage is present during pressing the main switch, and then approx. 12 V is
present while switch is turned ON.

“0”volt is present when switch is turned OFF.
Brake switch 16Turn the cruise main switch to ON and leave clutch pedal released (MT).
Then check that;

“0”volt is present when brake pedal is depressed.

Battery voltage is present when brake pedal is released.
Additionally only in MT vehicle, keep the cruise main switch to ON and leave brake pedal
released.
Then check that;

“0”volt is present when clutch pedal is depressed.

Battery voltage is present when clutch pedal is released.
Data link connector 17—
Data link connector 18—
Vehicle speed sensor 2 19Lift-up the vehicle until all four wheels are raised off ground, and then rotate any wheel manu-
ally.
Approx. 5 and 0 volt pulse signals are alternately input to cruise control module.
Stop light switch 20Turn ignition switch to OFF.
Then check that;

Battery voltage is present when brake pedal is depressed.

“0”volt is present when brake pedal is released.
NOTE:
Voltage at terminals 5, 7, 13 and 14 cannot be checked unless vehicle is driving by cruise control operation.
7
6-2BODY ELECTRICAL SYSTEM
5. Control Module I/O Signal

2. CRUISE CANCEL CONDITIONS DIAGNOSIS
1) Connect select monitor.
2) Start the engine and turn cruise control main switch to
ON.
3) Set select monitor in“FB0”mode.
4) Drive vehicle at least 40 km/h (25 MPH) with cruise
speed set.
5) If cruise speed is canceled itself (without doing any
cancel operations), a trouble code will appear on select
monitor display.
CAUTION:

A trouble code will also appear when cruise cancel
is effected by driver. Do not confuse.

Have a co-worker ride in vehicle to assist in diagno-
sis during driving.
NOTE:
Trouble code will be cleared by turning ignition switch or
cruise control main switch to OFF.
3. REAL-TIME DIAGNOSIS
1) Connect select monitor.
2) Turn ignition switch and cruise control main switch to
ON.
3) Set select monitor in“FA 0”mode.
4) Ensure that normal indication is displayed when con-
trols are operated as indicated below:

When SET/COAST switch is pressed.

When RESUME/ACCEL switch is pressed.

When brake pedal is depressed. (Stop and brake switch
turns ON.)

When clutch pedal is depressed. (MT model)

When select lever is set to N position. (AT model)
10
6-2BODY ELECTRICAL SYSTEM
6. Diagnostics Chart for On-board Diagnosis System

G2M0931
B6M0287
3) Start the engine.
4) Shift on the gear position, and keep the vehicle speed
at constant.
5) Measure signal voltage.
Specified voltage (V): 2 V, or more
NOTE:

If the vehicle speed increases, the width of amplitude
(W) decreases.

If oscilloscope is not available, check input signal
(vehicle speed signal) by using a select monitor. (Refer to
the procedure as described below.)

Using the select monitor:
(1) Set the vehicle on free roller, or lift-up the vehicle and
support with safety stands.
(2) Turn ignition switch to OFF and set select monitor.
(3) Turn ignition switch to ON.
(4) Turn cruise control main switch to ON.
(5) Set select monitor in“F01”or“F02”mode.
(6) Drive the vehicle at speed greater than 40 km/h (25
MPH).
(7) Check that vehicle speed indication on select moni-
tor and speedometer are equal.
NOTE:

When there is a disconnection or short circuit in the har-
ness between the meter and the cruise control module, the
indicated value will be 0 to 1.0 km/h (0 to 0.6 MPH).

In“F01”mode, vehicle speed is indicated in mile per
hour (MPH).
In“F02”mode, vehicle speed is indicated in kilometer per
hour (km/h).
B3M0250
3. PERFORM A CIRCUIT TEST BETWEEN
COMBINATION METER AND CRUISE CONTROL
MODULE.
1) Turn ignition switch to OFF.
2) Remove combination meter.
B6M0194B
3) Disconnect connector from cruise control module.
4) Measure resistance of harness connector between
combination meter and cruise control module.
Connector & terminal / Specified resistance:
(i10) No. 10—(B94) No. 19 / 10Ω, max.
24
6-2BODY ELECTRICAL SYSTEM
8. Diagnostics Chart with Trouble Code

8) The table below lists the nominal sectional areas and
allowable currents of the wires.
Nominal
sectional area
mm
2
No. of strands/
strand diameterOutside
diameter of
finished wiring
mmAllowable
current
Amps/40°C
0.3 7/0.26 1.8 7
0.5 7/0.32 2.2 (or 2.0) 12
0.75 30/0.18 2.6 (or 2.4) 16
0.85 11/0.32 2.4 (or 2.2) 16
1.25 16/0.32 2.7 (or 2.5) 21
2 26/0.32 3.1 (or 2.9) 28
3 41/0.32 3.8 (or 3.6) 38
5 65/0.32 4.6 (or 4.4) 51
8 50/0.45 5.5 67
CAUTION:
When replacing or repairing a wire, be sure to use the
same size and type of the wire which was originally
used.
NOTE:

The allowable current in the above table indicates the
tolerable amperage of each wire at an ambient tempera-
ture of 40°C (104°F).

The allowable current changes with ambient tempera-
ture. Also, it changes if a bundle of more than two wires is
used.
G6M0203
9) Each unit is directly grounded to the body or indirectly
grounds through a harness ground terminal. Different sym-
bols are used in the wiring diagram to identify the two
grounding systems.
The ground points shown in the wiring diagram refer to the
following:
GBBody ground
GEEngine ground
GRRadio ground
GDRear defogger ground
All wiring harnesses are provided with a ground point which
should be securely connected.
5
6-3WIRING DIAGRAM
1. General Description

G6M0205
11) Each connector number shown in the wiring diagram
corresponds to that in the wiring harness. The location of
each connector in the actual vehicle is determined by read-
ing the first character of the connector (for example, a“F”
for F8,“i”for i16, etc.) and the type of wiring harness.
The first character of each connector number refers to the
area or system of the vehicle, as indicated in table below.
Symbol Wiring harness and Cord
F Front wiring harness
B Bulkhead wiring harness
E Engine wiring harness
T Transmission cord
D Door cord LH & RH, Rear gate cord
I Instrument panel wiring harness
RRear wiring harness, Rear defogger cord
Room light cord,
Fuel tank cord,
Sunroof cord,
Trunk lid cord
P Floor wiring harness
7
6-3WIRING DIAGRAM
1. General Description

3. Working Precautions
1. PRECAUTIONS WHEN WORKING WITH THE
PARTS MOUNTED ON THE VEHICLE
1) When working under a vehicle which is jacked-up,
always be sure to use safety stands.
2) The parking brake must always be applied during work-
ing. Also, in automatic transmission vehicles, keep the
select lever set to the P (Parking) range.
3) Be sure the workshop is properly ventilated when run-
ning the engine. Further, be careful not to touch the belt or
fan while the engine is operating.
4) Be careful not to touch hot metal parts, especially the
radiator and exhaust system immediately after the engine
has been shut off.
2. PRECAUTIONS IN TROUBLE DIAGNOSIS AND
REPAIR OF ELECTRIC PARTS
1) The battery cable must be disconnected from the bat-
tery’s () terminal, and the ignition switch must be set to the
OFF position, unless otherwise required by the diagnos-
tics.
2) Securely fasten the wiring harness with clamps and
slips so that the harness does not interfere with the body
end parts or edges and bolts or screws.
3) When installing parts, be careful not to catch them on
the wiring harness.
G6M0212
4) When disconnecting a connector, do not pull the wires,
but pull while holding the connector body.
11
6-3WIRING DIAGRAM
3. Working Precautions

No. Load
MB-1Fuse holder (Rear power supply & seat
heater)
MB-2 Power window circuit breaker
MB-3Engine control module
Fuel pump relay
Main relay
OBD-II service connector
MB-4 A/C relay holder
MB-5 Headlight alarm relay (with security)
MB-6 Headlight LH
MB-7Daytime running light control module
Diode (Lighting)
Diode (Security)
Lighting switch
MB-8Combination meter
Front fog light switch
Headlight RH
Front fog light relay
MB-9Door lock timer
Headlight alarm relay
Interrupt relay
Radio
Security control module
Security indicator light
Spot light
Room light
Step light
Combination meter
Luggage room light
Trailer connector
Trunk room light
MB-10 A/C relay holder
SBF-6ABS relay box
TCS motor relay
SBF-7 TCS valve relay
ALT-1Combination meter
Daytime running light control module
Diode (TCS)
IG Headlight alarm relay
STCruise control module
Engine control module
Inhibitor switch (AT)
Interrupt relay
Starter interlock relay (MT)
FB-1Front washer motor
Rear washer motor
FB-2Engine control module
Main fan relay 1
FB-3Sub fan relay 2
Sub fan motor
FB-4Engine control module
Fuel pump relay
Ignition coil
Transmission control moduleNo. Load
FB-5 ABS relay box
FB-6Side marker light LH
Side marker light RH
FB-7 Door lock timer
FB-9 Hazard switch
FB-10AT shift lock control module
Key warning switch
Power antenna
FB-11 Radio
FB-12 Front accessory power supply
FB-13Mirror heater
Rear power supply relay
Remote control rearview mirror switch
Security control module
Vanity mirror illumination light
FB-14AT shift lock control module
Combination switch
Front wiper motor
Rear wiper motor
Rear wiper relay
FB-15ABS/TCS control module
Transmission control module
FB-16Rear defogger
Rear defogger condenser
Rear defogger switch
FB-17 Rear defogger switch
FB-18AT shift lock control module
Back-up light switch (MT)
Inhibitor switch (AT)
FB-19 Hazard switch
FB-20A/C switch
Combination meter
Mode control panel
TCS off switch
FB-22Blower motor relay
Check connector
Daytime running light control module
Daytime running light relay
FRESH/RECIRC actuator
Hi-beam relay
Power window and sunroof relay
Seat belt timer
FB-23 Airbag control module
FB-24 Airbag control module
FB-25 Lighting switch
20
6-3WIRING DIAGRAM
6. Wiring Diagram

No. Load
MB-2 Power window circuit breaker
MB-3Engine control module
Fuel pump relay
Main relay
OBD-II service connector
MB-4 A/C relay holder
MB-6 Headlight LH
MB-7Diode (Lighting)
Lighting switch
MB-8Combination meter
Headlight RH
MB-9Combination meter
Door lock timer
Luggage room light
Radio
Room light
MB-10 A/C relay holder
ALT-1 Combination meter
IG A/C relay holder
STCruise control module
Engine control module
Inhibitor switch
FB-2Engine control module
Main fan relay 1
FB-3Sub fan motor
Sub fan relay-2
FB-4Engine control module
Fuel pump relay
Ignition coil
Transmission control module
FB-6Side marker light LH
Side marker light RH
FB-7 Door lock timer
FB-9 Hazard switch
FB-10AT shift lock control module
Key warning switch
Power antenna
FB-11 Radio
FB-12 Cigarette lighter
FB-13 Remote control rearview mirror switch
FB-14AT shift lock control module
Combination switch
Front washer motor
Front wiper motor
Rear washer motor
Rear wiper motor
Rear wiper relayNo. Load
FB-15 Transmission control module
FB-16Rear defogger
Rear defogger condenser
Rear defogger switch
FB-17 Rear defogger switch
FB-18AT shift lock control module
Inhibitor switch
FB-19 Hazard switch
FB-20Combination meter
Mode control panel
FB-22Blower motor relay
Check connector
FRESH/RECIRC actuator
Mode actuator
Power window relay
Seat belt timer
FB-23 Airbag control module
FB-24 Airbag control module
FB-25 Lighting switch
FB-26 Parking switch
FB-27 Parking switch
FB-28 Illumination light
FB-29 Illumination light
FB-30Stop light switch
Stop & brake switch
FB-31 Horn relay
FB-32 Blower motor relay
FB-33 Parking switch
FB-34License plate light LH
License plate light RH
Rear combination light LH
Rear combination light RH
Rear finisher light LH
Rear finisher light RH
FB-35Cruise control main switch
Cruise control module
FB-38 Main fan relay 1
24
6-3WIRING DIAGRAM
6. Wiring Diagram

13. ENGINE ELECTRICAL SYSTEM

LHD 2200 cc engine AWD model
BU10-05A
51
6-3WIRING DIAGRAM
6. Wiring Diagram

13. ENGINE ELECTRICAL SYSTEM

LHD other models
BU10-06A
55
6-3WIRING DIAGRAM
6. Wiring Diagram