1995 SUBARU LEGACY air condition

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

3. READ DATA LIST

MODE $01
—Current powertrain diagnostic data—
Refers to data denoting the current operating condition of
analog input/output, digital input/output and/or the power-
train system.
A list of the support data and PID (Parameter Identification)
codes are shown in the following table.
PID DataUnit of measure
01 Number of emission-related powertrain trouble codes and MIL status ON/OFF
03 Fuel system control status—
04 Calculated engine load value%
05 Engine coolant temperature°C
06 Short term fuel trim%
07 Long term fuel trim%
0B Intake manifold absolute pressurekPa
0C Engine revolutionrpm
0D Vehicle speedkm/h
0E Ignition timing advance°
10 Air flow rate from mass air flow sensor g/sec
11 Throttle valve opening angle%
13 Check whether oxygen sensor is installed.—
14 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor—bank 1 V and %
15 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor—bank 2 V and %
1C On-board diagnosis system—
NOTE:
Refer to OBD-II general scan tool manufacturer’s instruc-
tion manual to access generic OBD-II PIDs (MODE $01).
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

3. FA MODE FOR ENGINE
Function
modeLED No. Contents Display LED“ON”requirements
FA 01 Ignition switch IG When ignition switch is turned ON.
2 AT/MT identification signal AT When AT identification signal is entered.
3 Test mode connector UD When test mode connector is connected.
5 Idle speed control identification signal ICWhen engine rpm is less than the established
value.
7 Neutral switch NT When neutral position signal is entered.
FA 12 Air conditioner switch AC When air conditioner switch is turned ON.
3 Air conditioner relay AR When air conditioner relay is in function.
4 Radiator fan relay 1 R1 When radiator fan relay 1 is in function.
5 Radiator fan relay 2 R2 When radiator fan relay 2 is in function.
6 Fuel pump relay FP When fuel pump relay is in function.
7 Purge control solenoid valve CP When purge control solenoid valve is in function.
9 Pressure sources switching solenoid valve BRWhen pressure sources switching solenoid valve
is in function.
FA 23 EGR solenoid valve EG When EGR solenoid valve is in function.
4 Engine torque control signal TR When engine torque control signal is entered.
5 Engine torque control cut signal TC When engine torque control cut signal is got out.
9 Front oxygen sensor signal FO When front oxygen sensor mixture ratio is rich.
10 Rear oxygen sensor signal RO When rear oxygen sensor mixture ratio is rich.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

G3M0151
6) After the display is gone, turn Subaru select monitor
switch and ignition switch to OFF.
NOTE:
When the ECM, battery terminals, etc. are disconnected
after memory is cleared, idling speed may increase. This is
not considered a problem because the ISC valve duty con-
trolled learning value has been cleared. To return the
engine to idling speed, idle for approximately 2 minutes
with air conditioner off.
2. OBD-II GENERAL SCAN TOOL
For clear memory procedures using the OBD-II general
scan tool, refer to the OBD-II General Scan Tool Instruction
Manual.
OBD0072A
E: INSPECTION MODE
1. PREPARATIONS FOR THE INSPECTION MODE
Raise the vehicle using a garage jack and place on safety
stands or drive the vehicle onto free rollers.

FULL-TIME AWD MODELS
WARNING:

Before raising the vehicle, ensure parking brakes
are applied.

Do not use a pantograph jack in place of a safety
stand.

Secure a rope or wire to the front and rear towing or
tie-down hooks to prevent the lateral runout of front
wheels.

Do not abruptly depress/release clutch pedal or
accelerator pedal during works even when engine is
operating at low speeds since this may cause vehicle
to jump off free rollers.

In order to prevent the vehicle from slipping due to
vibration, do not place any wooden blocks or similar
items between the safety stands and the vehicle.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

ContentConnector
No.Terminal
No.Signal (V)
Note Ignition SW
Engine ON (Idling)
ON (Engine OFF)
GND (injectors) B8471
00—
72
GND (ignition system) B84 69 0 0—
GND (power supply) B8495
00—
96
GND (control systems) B8445
00—
46
GND (oxygen sensor
heater)B84 70 0 0—
2. ENGINE CONDITION DATA
Content Specified data
Mass air flow1.9—3.6 (g/sec): Idling
7.0—14.8 (g/sec): 2,500 rpm racing
Engine load1.9—3.6 (%): Idling
7.0—14.8 (%): 2,500 rpm racing
Measuring condition:

Engine is warmed up.

Gear position is in“N”or“P”position.

A/C is turned OFF.

All accessory switches are turned OFF.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
5. Specified Data

ContentConnector
No.Terminal
No.Measuring conditionsVoltage
(V)Resistance to
body
(ohms)
Throttle position
sensorB54 8Throttle fully closed. 0.3—0.7
—
Throttle fully open. 4.3—4.9
Throttle position
sensor power
supplyB56 19Ignition switch ON (with engine
OFF)4.8—5.3—
ATF temperature
sensorB54 10ATF temperature 20°C(68°F) 2.9—4.0 2.1 k—2.9 k
ATF temperature 80°C (176°F) 1.0—1.4 275—375
Vehicle speed
sensor 1B54 12Vehicle stopped. 0
450—720
Vehicle speed at least 20 km/h (12
MPH)More than 1 (AC range)
Vehicle speed
sensor 2B56 11When vehicle is slowly moved at
least 2 meters (7ft).Less than 1)More than 9—
Engine speed
signalB54 5Ignition switch ON (with engine
OFF).More than 10.5
—
Ignition switch ON (with engine ON). 8—11
Cruise set signal B56 3When cruise control is set (SET
lamp ON).Less than 1
—
When cruise control is not set (SET
lamp OFF).More than 6.5
Torque control
signalB55 16 Ignition switch ON 4—6—
Torque control cut
signalB56 16 Ignition switch ON 6—9—
Mass air flow
signalB54 9 Engine idling after warm-up 0.5—1.2—
Shift solenoid 1 B55 141st or 4th gear More than 9
20—32
2nd or 3rd gear Less than 1
Shift solenoid 2 B55 131st or 2nd gear More than 9
20—32
3rd or 4th gear Less than 1
Shift solenoid 3 B55 15Selector lever in“N”range (with
throttle fully closed).Less than 1
20—32
Selector lever in“D”range (with
throttle fully closed).More than 9
Duty solenoid A B55 8Throttle fully closed (with engine
OFF) after warm-up.1.5—4.0
1.5—4.5
Throttle fully open (with engine
OFF) after warm-up.Less than 0.5
Dropping resistor B55 7Throttle fully closed (with engine
OFF) after warm-up.5—14
12—18
Throttle fully open (with engine
OFF) after warm-up.Less than 0.5
Duty solenoid B B55 5When lock up occurs. More than 8.5
9—17
When lock up is released. Less than 0.5
Duty solenoid C
(AWD model only)B55 3Fuse on FWD switch More than 8.5
9—17 Fuse removed from FWD switch
(with throttle fully open and with
select lever in 1st gear).Less than 0.5
Sensor ground
line 1B54 7—0 Less than 1
Sensor ground
line 2B56 20—0 Less than 1
System ground
lineB56 1—0 Less than 1
Power system
ground lineB55 10—0 Less than 1
FWD switch
(AWD model only)B56 2Fuse removed. 6—9.1
—
Fuse installed. Less than 1
Data link signal
(Subaru select
monitor)B5612——
—
13——
AT diagnosis
signalB56 11 Ignition switch ON Less than 1)More than 4—
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
5. Specified Data

2. CHECK LIST FOR INTERVIEW
Check the following items when problem occurred.
Customer’s name Engine no.
Date of sale Fuel brand
Date of repair Odometer readingkm
miles
Vin no.
WeatherFineCloudyRainySnowyVarious/Other
Outdoor TemperatureHotWarmCoolCold (approx.°F/°C)
PlaceHighwaySuburbsInner CityUphillDownhill
Rough roadOther
Engine Temp.ColdWarming-upAfter warming-upAny temp.Other
Engine speed
0 2,000 4,000 6,000 8,000 rpm
Driving conditionsNot affected
At startingWhile idlingAt racing
While acceleratingWhile cruising
While deceleratingWhile turning (RH/LH)
Vehicle speed
0 10203040 5060MPH
HeadlightON /OFF
BlowerON /OFF
A/C compressorON /OFF
Cooling fanON /OFF
Front wiperON /OFF
Rear wiperON /OFF
Rear defoggerON /OFF
RadioON /OFF
CD/CassetteON /OFF
Car phoneON /OFF
CB
NOTE: Use copies of this page for interviewing customers.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Basic Diagnostics Procedure

OBD0142
B: DTC P0100
—MASS AIR FLOW SENSOR CIRCUIT
MALFUNCTION (QA)—
OBD0143A
DESCRIPTION:

The MFI system employs a hot film type air flow sensor.
These mass air flow sensors convert the amount of air
taken into the engine into an electric signal by utilizing the
heat transfer phenomenon between the incoming air and a
heating resistor (hot film) located in the air intake.

The features of these flow sensor types are as follows:
1) High-altitude compensation is made automatically.
2) Quick response
3) These are no moving parts.
4) They are compact.
DTC DETECTING CONDITION:

Immediately at fault recognition
TROUBLE SYMPTOM:

Erroneous idling

Engine stalls.

Poor driving performance
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code