1997 SUBARU LEGACY fuel

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
spec. vehicles

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
spec. vehicles

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 spec.
vehicles
Vent control solenoid
valveB84 35ON: 1, or less
OFF: 10—13ON: 1, or less
OFF: 13—142200 cc AWD except Taiwan spec.
vehicles
TCS signal B84 61 0—70—7 Waveform
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
5. Specified Data

B: CHECK LIST FOR INTERVIEW
1. CHECK LIST NO. 1
Check the following items when problem has occurred.
NOTE:
Use copies of this page for interviewing customers.
Customer’s name Engine no.
Date of sale Fuel brand
Date of repair Odometer reading km
Vin no.miles
WeatherFine
Cloudy
Rainy
Snowy
Various/Others:
Outdoor temperature F(°C)
Hot
Warm
Cool
Cold
PlaceHighway
Suburbs
Inner city
Uphill
Downhill
Rough road
Others:
Engine temperatureCold
Warming-up
After warming-up
Any temperature
Others:
Engine speed rpm
Vehicle speed MPH
Driving conditionsNot affected
At starting
While idling
At racing
While accelerating
While cruising
While decelerating
While turning (RH/LH)
HeadlightON/OFF Rear defoggerON/OFF
BlowerON/OFF RadioON/OFF
A/C compressorON/OFF CD/CassetteON/OFF
Cooling fanON/OFF Car phoneON/OFF
Front wiperON/OFF CBON/OFF
Rear wiperON/OFF
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
6. Basic Diagnostic Procedure

2. CHECK LIST NO. 2
Check the following items about the vehicle’s state when
MIL turns on.
NOTE:
Use copies of this page for interviewing customers.
a) Other warning lights or indicators turn on.Yes/No
Low fuel warning light
Charge indicator light
AT diagnostics indicator light
ABS warning light
TCS warning light
Engine oil pressure warning light
b) Fuel level

Lack of gasoline:Yes/No

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

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

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

What:

Where:
f) Occurrence of noise:Yes/No

From where:

What kind:
g) Occurrence of smell:Yes/No

From where:

What kind:
h) Intrusion of water into engine compartment or passenger compartment:Yes/No
i) Troubles occurred
Engine does not start.
Engine stalls during idling.
Engine stalls while driving.
Engine speed decreases.
Engine speed does not decrease.
Rough idling
Poor acceleration
Back fire
After fire
No shift
Excessive shift shock
87
2-7ON-BOARD DIAGNOSTICS II SYSTEM
6. Basic Diagnostic Procedure

8. Diagnostics for Engine Starting
Failure
A: BASIC DIAGNOSTICS CHART
Inspection of starter motor circuit.
Inspection of ECM power supply and ground line.
Inspection of ignition control system.
Inspection of fuel pump circuit.
Inspection of fuel injector circuit.
Inspection of crankshaft position sensor circuit.
Inspection of camshaft position sensor circuit.
Inspection using Subaru select monitor or OBD-II
general scan tool or inspection using“9. General
Diagnostics Table.







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2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

D: IGNITION CONTROL SYSTEM
WIRING DIAGRAM:
B2M0522
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

OBD0727B
B2M0644B
8D1
CHECK IGNITION SYSTEM FOR SPARKS.
1) Remove plug cord cap from each spark plug.
2) Install new spark plug on plug cord cap.
CAUTION:
Do not remove spark plug from engine.
3) Contact spark plug’s thread portion on engine.
4) While opening throttle valve fully, crank engine to check
that spark occurs at each cylinder.
: Does spark occur at each cylinder?
: Check fuel pump system. [T8F0].>
: Go to step8D2.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B2M0523A
8D7CHECK HARNESS BETWEEN ECM AND
IGNITOR CONNECTOR.
1) Disconnect connector from ECM.
2) Measure resistance of harness connector between
ECM and ignitor.
: Connector & terminal
(B84) No. 41—(B13) No. 1:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between ECM and
ignitor connector.
: Connector & terminal
(B84) No. 40—(B13) No. 2:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between ECM and
ignitor connector.
: Connector & terminal
(B84) No. 94—(B13) No. 3:
Is the resistance less than 1Ω?
: Repair open circuit in harness between ECM and
ignitor connector.
: Go to next step 3).
B2M0524A
3) Measure resistance of harness connector between
ECM and chassis ground.
: Connector & terminal
(B84) No. 41—Chassis ground:
Is the resistance more than 1 MΩ?
: Go to next.
: Repair ground short circuit in harness between
ECM and ignitor connector.
: Connector & terminal
(B84) No. 40—Chassis ground:
Is the resistance more than 1 MΩ?
: Go to next.
: Repair ground short circuit in harness between
ECM and ignitor connector.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Check fuel pump circuit. [T8F0].>
111
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

E: FUEL PUMP CIRCUIT (2200 cc FWD, 2500
cc AWD TAIWAN SPEC. VEHICLES)
WIRING DIAGRAM:
B2M1052
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

11 2
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

8E1CHECK OPERATING SOUND OF FUEL
PUMP.
Make sure that fuel pump is in operation for two seconds
when turning ignition switch to ON.
: Does fuel pump produce operating sound?
NOTE:
Fuel pump operation check can also be executed using
Subaru Select Monitor (Function mode: FD01).
For the procedure, refer to“COMPULSORY VALVE
OPERATION CHECK MODE”.
: Check fuel injector circuit.
: Go to step8E2.
OBD0132A
8E2CHECK GROUND CIRCUIT OF FUEL
PUMP.
1) Turn ignition switch to OFF.
2) Disconnect connector from fuel pump.
3) Measure resistance of harness connector between fuel
pump and chassis ground.
: Connector & terminal
(R58) No. 4—Chassis ground:
Is the resistance less than 5Ω?
: Go to step8E3.
: Repair open circuit in fuel pump ground circuit.
OBD0133A
8E3
CHECK POWER SUPPLY TO FUEL PUMP.
1) Turn ignition switch to ON.
2) Measure voltage of power supply circuit between fuel
pump connector and chassis ground.
: Connector & terminal
(R58) No. 1 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Replace fuel pump.
: Go to step8E4.
11 3
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure