1997 SUBARU LEGACY check engine

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

6. Basic Diagnostic 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”. [T800].>
Malfunction indicator lamp (MIL) illu-
minates.
Ye sNoInspection using“9. General Diag-
nostics Table”.
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 for LHD
Vehicles”.
“11. Diagnostics Chart with Trouble
Code for RHD Vehicles”. [T1100].>
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. [T700].>

*2: Carry out the basic check, only when trouble code
about automatic transmission is shown on display. 2-7 [T6A0].>






84
2-7ON-BOARD DIAGNOSTICS II SYSTEM
6. Basic Diagnostic Procedure

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
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
6. Basic Diagnostic 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.
WIRING DIAGRAM:
B2M0507
88
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.
89
2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

B2M0510A
7A3CHECK HARNESS BETWEEN COMBINA-
TION METER AND IGNITION SWITCH
CONNECTOR.
1) Turn ignition switch to ON.
2) Measure voltage between combination meter connector
and chassis ground.
: Connector & terminal
(i14) No. 11 (+)—Chassis ground ():
Is voltage more than 10 V?
: Go to next.
: Check the following and repair if necessary.

Blown out fuse (No. 15).
NOTE:
If replaced fuse (No. 15) blows easily, check the harness
for short circuit of harness between fuse (No. 15) and com-
bination meter connector.

Open or short circuit in harness between fuse (No. 15)
and combination meter connector

Open or short circuit in harness between fuse (No. 15)
and ignition switch connector

Poor contact in ignition switch connector
: Is there poor contact in combination meter
connector?
: Repair poor contact in combination meter connec-
tor.
: Replace bulb or combination meter.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

B: CHECK ENGINE MALFUNCTION
INDICATOR LAMP (MIL) DOES NOT GO OFF.
DIAGNOSIS:

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

Although MIL comes on when engine runs, trouble code
is not shown on Subaru select monitor or OBD-II general
scan tool display.
WIRING DIAGRAM:
B2M0507
91
2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)