OBD SUBARU LEGACY 1995 Service Repair Manual

3. Engine Idle Speed
A: MEASUREMENT
1) Before checking idle speed, check the following:
(1) Ensure that air cleaner element is free from
clogging, ignition timing is correct, spark plugs are in
good condition, and that hoses are connected properly.
(2) Ensure that malfunction indicator light (CHECK
ENGINE light) does not illuminate.
2) Warm-up the engine.
G2M0096
3) Connect Subaru Select Monitor or the OBD-II general
scan tool to data link connector.
CAUTION:
When connecting Subaru Select Monitor, turn ignition
switch to OFF.
4) Start the engine and measure engine speed.
NOTE:
Engine speed is indicated on Subaru Select Monitor by
selecting “MODE F04”.
G2M0097
NOTE:

When using the OBD-II general scan tool, carefully read
its operation manual.

When Subaru Select Monitor is not used, attach the
pickup sensor on tachometer (Secondary pickup type) to
#1 cylinder spark plug cord.

This ignition system provides simultaneous ignition for
#1 and #2 plugs. It must be noted that some tachometers
may register twice that of actual engine speed.
3
2-2
3. Engine Idle Speed

G6M0095
17. Transmission Control Module
A: REMOVAL
1) Disconnect battery ground cable.
B3M0377A
2) Remove lower cover and then disconnect connector.
OBD0040
3) Remove TCM from steering support beam.
4) Disconnect connectors form TCM

1.
OBD0040
B: INSTALLATION
1) Connect connectors to TCM
1.
2) Install TCM to steering support beam.
Tightening torque:
7.4±2.0 N⋅m (0.75±0.2 kg-m, 5.4±1.4 ft-lb)
3) Installing procedure hereafter is in the reverse order of
removal.
11 3
3-2SERVICE PROCEDURE
17. Transmission Control Module

B4M0622A
D: AIR BLEEDING CONTROL WITH SELECT
MONITOR
1) Connect select monitor to data link connector beside
driver’s seat instrument panel lower.

1Data link connector (for Subaru select monitor and
OBD-II general scan tool)

2Data link connector (for Subaru select monitor)
NOTE:
When using data link connector
1above, use ST.
ST 498357200 ADAPTER CABLE
2) Start the engine.
3) Change select monitor to TCS mode by pressing the
function key.
B4M0623
4) Press FD3 ENT key.
B4M0624
5) When the message shown in the figure is displayed,
press ENT key.
B4M0625
6) Air bleeding control operation starts.
83
4-4SERVICE PROCEDURE
19. Air Bleeding (With TCS model)

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

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

1Engine control module (ECM)

2Ignition coil

3Ignitor

4Crankshaft position sensor

5Camshaft position sensor

6Throttle position sensor

7Fuel injectors

8Pressure regulator

9Engine coolant temperature sensor

10Mass air flow sensor

11Idle air control solenoid valve

12Purge control solenoid valve

13Fuel pump

14PCV valve

15Air cleaner

16Canister

17Main relay

18Fuel pump relay

19Fuel filter

20Front catalytic converter

21Rear catalytic converter

22EGR valve
23EGR control solenoid valve

24Radiator fan

25Radiator fan relay

26Pressure sources switching solenoid valve (AT vehicles only)

27Knock sensor

28Back-pressure transducer (AT vehicles only)

29Front oxygen sensor

30Rear oxygen sensor

31Pressure sensor (AT vehicles only)

32A/C compressor

33Inhibitor switch

34CHECK ENGINE malfunction indicator lamp (MIL)

35Tachometer

36A/C relay

37A/C control module

38Ignition switch

39Transmission control module (TCM) (AT vehicles only)

40ABS/TCS control module (TCS equipped models)

41Vehicle speed sensor

42Data link connector (Subaru select monitor)

43Data link connector (OBD-II general scan tool)

44Two way valve
5
2-7ON-BOARD DIAGNOSTICS II SYSTEM
1. General

2. Electrical Components Location
A: ENGINE
1. MODULE (LHD MODEL)
OBD0003A
1Engine control module (ECM)

2Data link connector (for Subaru select monitor only)

3Data link connector (for Subaru select monitor and OBD-II
general scan tool)
4Test mode connector

5CHECK ENGINE malfunction indicator lamp (MIL)
OBD0004AOBD0005D
OBD0006BOBD0008A
8
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location

2. MODULE (RHD MODEL)
B2M0430A
1Engine control module (ECM)

2Data link connector (for Subaru select monitor only)

3Data link connector (for Subaru select monitor and OBD-II
general scan tool)
4Test mode connector

5CHECK ENGINE malfunction indicator lamp (MIL)
B2M0431AB2M0432A
B2M0433AOBD0008A
9
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location

3. SENSOR
OBD0009A
1Pressure sensor (AT vehicles only)

2Mass air flow sensor

3Engine coolant temperature sensor

4Throttle position sensor
5Knock sensor

6Camshaft position sensor

7Crankshaft position sensor
OBD0010AOBD0011A
10
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location

OBD0012AOBD0013A
OBD0014AOBD0015A
B2M0213B
11
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location