SUBARU LEGACY 1995 Service Repair Manual

B6M0446A
Trunk lid (SEDAN)
Connector & terminal / Specified voltage:
(B93) No. 15—Body/1V,max.
(UNLOCK position)
/ 10 V, or more (other than
UNLOCK position)
B6M0409A
3) Measure voltage between security control module con-
nector and body while removing/installing key cylinder
switch from/to door outer handle.
Connector & terminal / Specified voltage:
(B93) No. 3—Body / 10 V, or more
(Switch is installed.)
/ 1 V, max.
(Switch is removed.)
NOTE:
For SEDAN vehicles, remove key cylinder switch from
trunk lid key cylinder to perform the above inspection.
2. CHECK KEY CYLINDER SWITCH.
Refer to 6-2 [W22B4] for inspection of key cylinder lock/
unlock switch and tamper switch.
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6-2DIAGNOSTICS
6. Security System

L: DIAGNOSTICS PROCEDURE FOR
STARTER INTERRUPT SIGNAL
1. Check starter interrupt output signal for security
control module.
Not OK
OK
5. Check starter interrupt relay.
OK Not OK
Repair or replace
wiring harness of
starter motor circuit.
Replace starter
interrupt relay.
2. Check power supply for starter interrupt relay.
OK
Not OK
Repair or replace wiring harness between starter
interrupt relay and battery.
3. Check continuity of starter interrupt relay.
OK
Not OK
Replace starter interrupt relay.
4. Check harness connector between starter
interrupt relay and security control module.
OK
Not OK
Repair or replace wiring harness between starter
interrupt relay and security control module.
Replace security control module.
B6M0445A
1. CHECK STARTER INTERRUPT OUTPUT SIGNAL
FOR SECURITY CONTROL MODULE.
1) Remove security control module without disconnecting
connector.
2) Measure voltage between security control module con-
nector and body.
Connector & terminal / Specified voltage:
(B93) No. 5—Body / 10 V, or more
3) Set security system in armed state.
4) Open the door without ignition key to operate the secu-
rity system (alarm state).
5) Measure voltage between security control module and
body during alarm state.
Connector & terminal / Specified voltage:
(B93) No. 5—Body/1V,max.





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6-2DIAGNOSTICS
6. Security System

B6M0506A
2. CHECK POWER SUPPLY FOR STARTER
INTERRUPT RELAY.
1) Remove starter interrupt relay without disconnecting
connector.
2) Measure voltage between starter interrupt relay con-
nector and body.
Connector & terminal / Specified voltage:
(B59) No. 1—Body / 10 V, or more
B6M0455
3. CHECK CONTINUITY OF STARTER INTERRUPT
RELAY.
1) Remove starter interrupt relay.
2) Check continuity between terminals No. 1 and No. 2 of
starter interrupt relay.
B6M0500A
4. CHECK HARNESS CONNECTOR BETWEEN
STARTER INTERRUPT RELAY AND SECURITY
CONTROL MODULE.
1) Disconnect connectors of starter interrupt relay and
security control module.
2) Measure resistance of harness connector between
starter interrupt relay and security control module.
Connector & terminal / Specified resistance:
(B59) No. 2—(B93) No.5/10Ω, max.
5. CHECK STARTER INTERRUPT RELAY.
Refer to 6-2 [W22B1] for inspection of starter interrupt
relay.
99
6-2DIAGNOSTICS
6. Security System

M: DIAGNOSTICS PROCEDURE FOR HORN
ALARM SIGNAL
1. Check horn alarm output signal for security
control module.
Not OK
OK
5. Check horn relay.
OK Not OK
Repair or replace
wiring harness of horn
circuit.
Replace horn relay.
2. Check power supply for horn relay.
OK
Not OK
Repair or replace wiring harness between horn
relay and battery.
3. Check continuity of horn relay.
OK
Not OK
Replace horn relay.
4. Check harness connector between horn relay
and security control module.
OK
Not OK
Repair or replace wiring harness between horn
relay and security control module.
Replace security control module.
B6M0461A
1. CHECK HORN ALARM OUTPUT SIGNAL FOR
SECURITY CONTROL MODULE.
1) Remove security control module without disconnecting
connector.
2) Measure voltage between security control module con-
nector and body.
Connector & terminal / Specified voltage:
(B93) No. 13—Body / 10 V, or more
3) Set security system in armed state.
4) Open the door without ignition key to operate the secu-
rity system (alarm state).
5) Measure voltage between security control module and
body during alarm state.
Connector & terminal / Specified voltage:
(B93) No. 13—Body / repeats 1 V, max. (0.2 sec.)
and 10 V, or more (0.6 sec.)
intervals





100
6-2DIAGNOSTICS
6. Security System

B6M0507A
2. CHECK POWER SUPPLY FOR HORN RELAY.
1) Check fuse No. 12.
2) Remove horn relay without disconnecting connector.
3) Measure voltage between horn relay connector and
body.
Connector & terminal / Specified voltage:
(B49) No. 2—Body / 10 V, or more
B6M0459
3. CHECK CONTINUITY OF HORN RELAY.
1) Remove horn relay.
2) Check continuity between terminals No. 1 and No. 2 of
horn relay.
B6M0501A
4. CHECK HARNESS CONNECTOR BETWEEN HORN
RELAY AND SECURITY CONTROL MODULE.
1) Disconnect connectors of horn relay and security con-
trol module.
2) Measure resistance of harness connector between horn
relay and security control module.
Connector & terminal / Specified resistance:
(B49) No. 1—(B93) No. 13 / 10Ω, max.
5. CHECK HORN RELAY.
Refer to 6-2 [W15B2] for inspection of horn relay.
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6-2DIAGNOSTICS
6. Security System

N: DIAGNOSTICS PROCEDURE FOR
HEADLIGHT ALARM SIGNAL
1. Check headlight alarm output signal for security
control module.
Not OK
OK
5. Check headlight alarm relay.
OK Not OK
Repair or replace
wiring harness of
headlight circuit.
Replace headlight
alarm relay.
2. Check power supply for headlight alarm relay.
OK
Not OK
Repair or replace wiring harness between
headlight alarm relay and battery.
3. Check continuity of headlight alarm relay.
OK
Not OK
Replace headlight alarm relay.
4. Check harness connector between headlight
alarm relay and security control module.
OK
Not OK
Repair or replace wiring harness between
headlight alarm relay and security control
module.
Replace security control module.
B6M0457A
1. CHECK HEADLIGHT ALARM OUTPUT SIGNAL
FOR SECURITY CONTROL MODULE.
1) Remove security control module without disconnecting
connector.
2) Measure voltage between security control module con-
nector and body.
Connector & terminal / Specified voltage:
(B93) No. 12—Body / 10 V, or more
3) Set security system in armed state.
4) Open the door without ignition key to operate the secu-
rity system (alarm state).
5) Measure voltage between security control module and
body during alarm state.
Connector & terminal / Specified voltage:
(B93) No. 12—Body / repeats 1 V, max. (0.2 sec.)
and 10 V, or more (0.6 sec.)
intervals





102
6-2DIAGNOSTICS
6. Security System

B6M0508A
2. CHECK POWER SUPPLY FOR HEADLIGHT ALARM
RELAY.
1) Remove headlight alarm relay without disconnecting
connector.
2) Measure voltage between headlight alarm relay con-
nector and body.
Connector & terminal / Specified voltage:
(B58) No. 1—Body / 10 V, or more
B6M0455A
3. CHECK CONTINUITY OF HEADLIGHT ALARM
RELAY.
1) Remove headlight alarm relay.
2) Check continuity between terminals No. 1 and No. 2 of
headlight alarm relay.
B6M0502A
4. CHECK HARNESS CONNECTOR BETWEEN
HEADLIGHT ALARM RELAY AND SECURITY
CONTROL MODULE.
1) Disconnect connectors of headlight alarm relay and
security control module.
2) Measure resistance of harness connector between
headlight alarm relay and security control module.
Connector & terminal / Specified resistance:
(B58) No. 2—(B93) No. 12 / 10Ω, max.
5. CHECK HEADLIGHT ALARM RELAY.
Refer to 6-2 [W22B2] for inspection of headlight alarm
relay.
103
6-2DIAGNOSTICS
6. Security System

1. General
1. GENERAL DESCRIPTION

The on-board diagnostics (OBD) system detects and
indicates a fault in various inputs and outputs of the com-
plex electronic control. CHECK ENGINE malfunction indi-
cator lamp (MIL) in the combination meter indicates occur-
rence of a fault or trouble.

Further, against such a failure or sensors as may disable
the drive, the fail-safe function is provided to ensure the
minimal driveability.

The OBD system incorporated with the vehicles within
this engine family complies with Section 1968.1, California
Code of Regulations (OBD-II regulation). The OBD system
monitors the components and the system malfunction
listed in Engine Section which affects on emissions.

When the system decides that a malfunction occurs, MIL
illuminates. At the same time of the MIL illumination or
blinking, a diagnostic trouble code (DTC) and a freeze
frame engine conditions are stored into on-board com-
puter.

The OBD system stores freeze frame engine condition
data (engine load, engine coolant temperature, fuel trim,
engine speed and vehicle speed, etc.) into on-board com-
puter when it detects a malfunction first.

If the OBD system detects the various malfunctions
including the fault of fuel trim or misfire, the OBD system
first stores freeze frame engine conditions about the fuel
trim or misfire.

When the malfunction does not occur again for three
trips, MIL is turned off, but DTC remains at on-board com-
puter.

The OBD-II system is capable of communication with a
general scan tool (OBD-II general scan tool) formed by ISO
9141 CARB.

The OBD-II diagnostics procedure is different from the
usual diagnostics procedure. When troubleshooting OBD-II
vehicles, connect Subaru select monitor or the OBD-II gen-
eral scan tool to the vehicle.
A: ENGINE
1. ENGINE AND EMISSION CONTROL SYSTEM

The Multipoint Fuel Injection (MFI) system is a system
that supplies the optimum air-fuel mixture to the engine for
all the various operating conditions through the use of the
latest electronic technology.
With this system fuel, which is pressurized at a constant
pressure, is injected into the intake air passage of the cyl-
inder head. The injection quantity of fuel is controlled by an
intermittent injection system where the electro-magnetic
injection valve (fuel injector) opens only for a short period
of time, depending on the quantity of air required for one
cycle of operation. In actual operation, the injection quan-
2
2-7ON-BOARD DIAGNOSTICS II SYSTEM
1. General

tity is determined by the duration of an electric pulse
applied to the fuel injector and this permits simple, yet
highly precise metering of the fuel.

Further, all the operating conditions of the engine are
converted into electric signals, and this results in additional
features of the system, such as large improved
adaptability, easier addition of compensating element, etc.
The MFI system also has the following features:
1) Reduced emission of harmful exhaust gases.
2) Reduced in fuel consumption.
3) Increased engine output.
4) Superior acceleration and deceleration.
5) Superior startability and warm-up performance in cold
weather since compensation is made for coolant and
intake air temperature.
3
2-7ON-BOARD DIAGNOSTICS II SYSTEM
1. General

2. SCHEMATIC
OBD0001A
4
2-7ON-BOARD DIAGNOSTICS II SYSTEM
1. General