engine SUBARU LEGACY 1996 Service Repair Manual

5. Specified Data
1. ENGINE CONTROL MODULE (ECM) I/O SIGNAL
OBD0092A
ContentConnector
No.Terminal
No.Signal (V)
Note
Ignition SW ON
(Engine OFF)Engine ON (Idling)
Crankshaft
position
sensorSignal (+) B84 8 07—+7 Sensor output waveform
Signal () B84 29 0 0—
Shield B84 54 0 0—
Camshaft
position
sensorSignal (+) B84 7 07—+7 Sensor output waveform
Signal () B84 28 0 0—
Shield B84 54 0 0—
Mass air
flow sensorSignal B84 5 0—0.3 0.8—1.2—
Shield B84 57 0 0—
GND B84 20 0 0—
Throttle
position
sensorSignal B84 6Fully closed: 0.2—1.0
Fully opened: 4.2—4.7—
Power
supplyB84 21 5 5—
GND B84 20 0 0—
Front
oxygen
sensorSignal B84 23 0 0—0.9—
Shield B84 56 0 0—
Rear
oxygen
sensorSignal B84 24 0 0—0.9—
Shield B84 56 0 0—
Engine coolant
temperature sensorB84 22 1.0—1.4 1.0—1.4 After warm-up
Vehicle speed sensor 2 B84 83 0 or 5 0 or 5“5”and“0”are repeatedly
displayed when vehicle is
driven.
Starter switch B84 86 0 0 Cranking: 8 to 14
A/C switch B84 60ON: 10—13
OFF: 0ON: 13—14
OFF: 0—
Ignition switch B84 85 10—13 13—14—
Neutral position switch
(MT)
B84 82ON: 5.0±0.5
OFF: 0
On MT model; switch is ON
when gear is in neutral position.
Neutral position switch
(AT)ON: 0
OFF: 5.0±0.5
On AT model; switch is ON when
shift is in“N”or“P”position.
Test mode connector B84 84 5 5 When connected: 0
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
5. Specified Data

ContentConnector
No.Terminal
No.Signal (V)
Note
Ignition SW ON
(Engine OFF)Engine ON (Idling)
Knock
sensorSignal B84 3 2.8 2.8—
Shield B84 56 0 0—
AT/MT identification B84 81(AT) 5
(MT) 0(AT) 5
(MT) 0When measuring voltage between
ECM and body.
Back-up power supply B84 39 10—13 13—14 Ignition switch“OFF”:10—13
Control unit power supply B841
10—13 13—14—
2
Ignition
control#1,#2 B84 41 0 1—3.4—
#3,#4 B84 40 0 1—3.4—
Fuel
injector# 1 B84 96 10—13 1—14 Waveform
# 2 B84 70 10—13 1—14 Waveform
# 3 B84 44 10—13 1—14 Waveform
# 4 B84 16 10—13 1—14 Waveform
Idle air
control
solenoid
valveOPEN end B84 14—1—13 Waveform
CLOSE end B84 13—13—1 Waveform
Fuel pump relay control B84 32ON: 0.5, or less
OFF: 10—130.5, or less—
A/C relay control B84 31ON: 0.5, or less
OFF: 10—13ON: 0.5, or less
OFF: 13—14—
Radiator fan relay 1
controlB84 74ON: 0.5, or less
OFF: 10—13ON: 0.5, or less
OFF: 13—14—
Radiator fan relay 2
controlB84 73ON: 0.5, or less
OFF: 10—13ON: 0.5, or less
OFF: 13—14With A/C vehicles only
Self-shutoff control B84 63 10—13 13—14—
Malfunction indicator lamp B84 58——Light“ON”:1,orless
Light“OFF”:10—14
Engine speed output B84 64—0—13, or more Waveform
Torque control signal B84 79 5 5—
Mass air flow signal for
ATB84 47 0—0.3 0.8—1.2—
Purge control solenoid
valveB84 72ON: 1, or less
OFF: 10—13ON: 1, or less
OFF: 13—14—
Atmospheric pressure
sensorB84 26 3.9—4.1 2.0—2.3—
Pressure sources
switching solenoid valveB84 15ON: 1, or less
OFF: 10—13ON: 1, or less
OFF: 13—14—
EGR solenoid valve B84 71ON: 1, or less
OFF: 10—13ON: 1, or less
OFF: 13—14—
Front oxygen sensor
heater signalB84 38 0—1.0 0—1.0—
Rear oxygen sensor
heater signalB84 37 0—1.0 0—1.0—
Fuel temperature sensor B84 25 2.5—3.8 2.5—3.8
2200 cc AWD except Taiwan
model

Ambient temperature: 25°C
(77°F)
Fuel level sensor B84 27 0.12—4.75 0.12—4.75 2200 cc AWD except Taiwan model
Fuel tank
pressure
sensorSignal B84 4 2.3—2.7 2.3—2.7
2200 cc AWD except Taiwan
model

The value obtained after the fuel
filler cap was removed once and
recapped.
Power
supplyB84 21 5 5—
GND B84 20 0 0—
Fuel tank pressure control
solenoid valveB84 10ON: 1, or less
OFF: 10—13ON: 1, or less
OFF: 13—142200 cc AWD except Taiwan model
Vent control solenoid
valveB84 35ON: 1, or less
OFF: 10—13ON: 1, or less
OFF: 13—142200 cc AWD except Taiwan model
TCS signal B84 61 0—70—7 Waveform
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
5. Specified Data

ContentConnector
No.Terminal
No.Signal (V)
Note
Ignition SW ON
(Engine OFF)Engine ON (Idling)
AT diagnosis input signal B84 80Less than 1)More
than 4Less than 1)More
than 4Waveform
GND (sensors) B84 20 0 0—
GND (injectors) B8469
00—
95
GND (ignition system) B84 94 0 0—
GND (power supply) B8419
00—
46
GND (control systems) B8417
00—
18
GND (oxygen sensor
heater)B84 42 0 0—
2. ENGINE CONDITION DATA
Content Model Specified data
Mass air flow2200 cc1.7—3.3 (g/sec): Idling
7.1—14.2 (g/sec): 2,500 rpm racing
2500 cc2.2—4.2 (g/sec): Idling
8.6—14.5 (g/sec): 2,500 rpm racing
Engine load2200 cc1.6—2.9 (%): Idling
6.4—12.8 (%): 2,500 rpm racing
2500 cc1.9—3.5 (%): Idling
7.2—12.1 (%): 2,500 rpm racing
Measuring condition:

After warm-up the engine.

Gear position is in“N”or“P”position.

A/C is turned OFF.

All accessory switches are turned OFF.
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5. Specified Data

3. TRANSMISSION CONTROL MODULE (TCM) I/O
SIGNAL
OBD0093A
Check with ignition switch ON.
ContentConnector
No.Terminal
No.Measuring conditions Voltage (V)
Back-up power supply B56 14 Ignition switch OFF 10—16
Ignition power supplyB54 6
Ignition switch ON (with engine OFF) 10—16
B55 1
Inhibitor switch“P”range switch B56 9Selector lever in“P”range Less than 1
Selector lever in any other than“P”
rangeMore than 8
“N”range switch B56 8Selector lever in“N”range Less than 1
Selector lever in any other than“N”
rangeMore than 8
“R”range switch B56 10Selector lever in“R”range Less than 1
Selector lever in any other than“R”
rangeMore than 6
“D”range switch B54 1Selector lever in“D”range Less than 1
Selector lever in any other than“D”
rangeMore than 6
“3”range switch B54 2Selector lever in“3”range Less than 1
Selector lever in any other than“3”
rangeMore than 6
“2”range switch B54 3Selector lever in“2”range Less than 1
Selector lever in any other than“2”
rangeMore than 6
“1”range switch B54 4Selector lever in“1”range Less than 1
Selector lever in any other than“1”
rangeMore than 6
Brake switch B56 7Brake pedal depressed More than 10.5
Brake pedal released Less than 1
ABS signal B56 5ABS switch ON Less than 1
ABS switch OFF More than 6.5
AT diagnostics signal B55 12Ignition switch ON (with engine OFF) Less than 1
Ignition switch ON (with engine ON) More than 10
Diagnosis switch B56 6Diagnosis connector connected. Less than 1
Diagnosis connector disconnected. More than 6
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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—
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 1
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

6. Basic Diagnostics Procedure
Trouble occurs.
Ask the customer when and how the
trouble occurred using interview
check list.
Start the engine.
Ye sNoInspection using“8. Diagnostics for
Engine Start Failure 2-7 [T800]”.
Malfunction indicator lamp (MIL) illu-
minates.
Ye sNoInspection using“9. General Diag-
nostics Table 2-7 [T900]”.
Inspection using Subaru select moni-
tor or OBD-II general scan tool.
(Subaru select monitor: MODE FB1)
Trouble code
No trouble code designated.Repair.
See NOTE: *1
designated.
Inspection using“10. Diagnostics
Chart with Trouble Code 2-7
[T1000]”.
See NOTE: *2.
Trouble code
designated.

Repair.
Inspection mode
Inspection using Subaru select moni-
tor or OBD-II general scan tool.
(Subaru select monitor: MODE FB0)
No trouble code
Clear memory mode.
designated.
END
NOTE:
*1: If trouble code is not shown on display although the
MIL illuminates, perform diagnostics of the MIL (CHECK
ENGINE LIGHT) circuit or combination meter. Diagnostics for CHECK ENGINE Malfunction Indicator
Lamp (MIL) 2-7 [T700].”>
*2: Carry out the basic check, only when trouble code
about automatic transmission is shown on display. 2-7 [T601].>






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6. Basic Diagnostics Procedure

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 102030405060MPH
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
6. Basic Diagnostics Procedure

Check the following items about the vehicle’s state when
MIL turns on.
a) Other warning lights or indicators turn on.Ye s /No

1Low fuel warning light

2Charge indicator light

3AT diagnostics indicator light

4ABS warning light

5TCS warning light

6Engine oil pressure warning light
b) Fuel level

Lack of gasoline:Ye s /No

Indicator position of fuel gauge:
c) Intentional connecting or disconnecting of harness connectors or spark plug cords:Ye s /No

What:
d) Intentional connecting or disconnecting of hoses:Ye s /No

What:
e) Installing of parts other than genuine partsYe s /No

What:

Where:
f) Occurrence of noiseYe s /No

From where:

What kind:
g) Occurrence of smellYe s /No

From where:

What kind:
h) Intrusion of water into engine compartment or passenger compartmentYe s /No
i) Troubles occurred

1Engine does not start.

2Engine stalls during idling.

3Engine stalls while driving.

4Engine speed decreases.

5Engine speed does not decrease.

6Rough idling

7Poor acceleration

8Back fire

9After fire

10No shift

11Excessive shift shock
NOTE: Use copies of this page for interviewing customers.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
6. Basic Diagnostics Procedure

7. Diagnostics for CHECK ENGINE
Malfunction Indicator Lamp (MIL)
A: CHECK ENGINE MALFUNCTION
INDICATOR LAMP (MIL) DOES NOT COME
ON.
DIAGNOSIS:

The CHECK ENGINE malfunction indicator lamp (MIL)
circuit is open or shorted.
TROUBLE SYMPTOM:

When ignition switch is turned ON (engine OFF), MIL
does not come on.
7A1Check output signal from ECM.
7A2Check harness between combination meter
and ECM connector.
7A3Check harness between combination meter
and ignition switch connector.
WIRING DIAGRAM:
B2M0507


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2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

B2M0508A
7A1
CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM connector and chassis
ground.
: Connector & terminal
(B84) No. 58 (+) — Chassis ground ():
Is the voltage less than 1 V?
: Go to step7A2.
: Go to next.
: Does the MIL come on when shaking or
pulling ECM connector and harness?
: Repair poor contact in ECM connector.
: Go to next.
: Is ECM connector correctly connected?
: Replace ECM.
: Repair connection of ECM connector.
B2M0763A
7A2CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Remove combination meter.
3) Disconnect connector from ECM and combination
meter.
4) Measure resistance of harness between ECM and com-
bination meter connector.
: Connector & terminal
(B84) No. 58 — (i14) No. 2:
Is resistance less than 1Ω?
: Go to next.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and combination
meter connector

Poor contact in coupling connector (B37)
: Is there poor contact in combination meter
connector?
: Repair poor contact in combination meter connec-
tor.
: Go to step7A3.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)