SUBARU LEGACY 1996 Service Repair Manual

Important safety notice

Providing appropriate service and repair is a matter of great importance in the serviceman’s safety maintenance
and safe operation, function and performance which the SUBARU vehicle possesses.

In case the replacement of parts or replenishment of consumables is required, genuine SUBARU parts whose
parts numbers are designated or their equivalents must be utilized.

It must be made well known that the safety of the serviceman and the safe operation of the vehicle would be
jeopardized if the used any service parts, consumables, special tools and work procedure manuals which are
not approved or designated by SUBARU.
All right reserved. This book may not be reproduced
or copied, in whole or in part, without the written
permission of FUJI HEAVY INDUSTRIES LTD.,
TOKYO JAPAN.
SUBARU,
andare trademarks of
FUJI HEAVY INDUSTRIES LTD.
© Copyright 1995 FUJI HEAVY INDUSTRIES LTD.
2

How to use this manual

This Service Manual is divided into four volumes by section so that it can be used with ease at work. Refer to
the Table of Contents, select and use the necessary section.

GENERAL INFORMATION SECTION

REPAIR SECTION

TROUBLESHOOTING SECTION

WIRING DIAGRAM SECTION

The description of each area is provided with four types of titles different in size as shown below. The Title No.
or Symbol prefixes each title in order that the construction of the article and the flow of explanation can be eas-
ily understood.
[Example of each title]

Area title: T. DIAGNOSTICS

Large title (Heading): 1. Diagnostics Chart with Select Monitor
(to denote the main item of explanation)

Medium title (Section): A: BASIC DIAGNOSTICS CHART
(to denote the type of work in principle)

Small title (Sub-section): 1. CHECK INPUT SIGNAL FOR ECM
(to denote a derivative item of explanation)
3

The Title Index No. is indicated on the top left (or right) side of the page as the book is opened. This is useful
for retrieving the necessary portion.
(Example of usage)
Refer to 3 - 2
[T5A0]
Small title (Sub-section)
Medium title (Section)
Large title (Heading)
DIAGNOSTICS
Chapter no.
4

In this manual, the following symbols are used.
Circuit tester
Voltage measurement
Circuit tester
Resistance measurement
The arrow indicates that insertion of the probe or numbering of the connector pins is
made from the side.
The arrow indicates that insertion of the probe or numbering of the connector pins is
made from the side.
Oscilloscope
Oscilloscope positive probe
Oscilloscope earth head

WARNING, CAUTION, NOTE

WARNING: Indicates the item which must be observed precisely during performance of maintenance ser-
vices in order to avoid injury to the mechanics and other persons.

CAUTION: Indicates that item which must be followed precisely during performance of maintenance ser-
vices so as to avoid damage and breakage to the vehicle and its parts and components.

NOTE: Indicates the hints, knacks, etc. which make the maintenance job easier.
5

Basic checks
DISCONNECTING CONNECTORS

Always hold the connector itself.
CAUTION:
Don’t pull the harness.

To disconnect a locking connector, first re-lease
the lock, then pull the connector off.


Insert a connector by pushing it all the way in. If
the connector is equipped with a locking device,
push it in until a clicking sound is heard.

INSERTING A PROBE

Generally, probes are inserted into connectors from the rear.

Connectors equipped with shock protectors must be checked
with a mini probe (thin), or it will be necessary to remove the shock
protector.

When removing the shock protector take care not to deform it;
this also applies to waterproof connectors, which cannot be tested
from the wire side.

When the connector has a back plate, remove the plate after
removing the projection of the plate first. (Be careful not to use
excessive force, since the terminals might brake off).
6

CHECKING FOR POOR CONTACT ON PLUG-IN CONNECTORS
Most intermittent problems are caused by poor contact of plug-in connectors.
Poor contact is frequently caused by corroded terminals, dirt, foreign substances, weak contact points between
male and female connectors, etc.
To help prevent the replacement of good component parts, sufficiently check the following points.

Quite often a plug with poor contact will work perfectly again
after it has been pulled off and reconnected.

Disconnect the two connector halves.

Check the connector pins for signs of corrosion or foreign
material.

Check the connector for loose and damaged terminals, and
make sure they are set correctly in the connector.
NOTE:
When the harness is pulled lightly, the terminals should not
come out.

Insert the male pin of the connector into the female pin, then
pull it out.
NOTE:
If one of the pins pulls out easily, it is a likely source of a mal-
function.

Lightly shake the connector and the harness, and check for
sudden changes in voltage or resistance.
If harness and connector checks do not reveal any defect, it can be assumed that an intermittent contact in a
connector is the source of trouble.
7

Diagnosis and checking procedure using instruments
USING A CIRCUIT TESTER
J3-1012

Voltage check (range set to DC V)
Connect the positive probe to the terminal to be tested, and
the negative probe to body ground (or the ground terminal of
the ECM)
J3-830

Checking the connection (range set toΩ)
Measure the resistance and check for open or shorted wire in
the harness or the connector.
NOTE:
This check must be carried out with both connectors discon-
nected.
(This avoids by-passing the connection through other circuits).
1) Check for open circuit (range:Ωx 1K)
Measure the resistance between the respective pins in both
connectors.
Specified resistance:
1MΩ, or more (No continuity) Open circuit
10Ω, or less (Continuity) O.K.
2) Check for correct insulation value (range:Ωx 1K)
Measure the resistance between the pins in both connectors,
as well as between the suspected pin and the body (body
short).
Specified resistance:
1MΩ, or more (No continuity) O.K.
10Ω, or less (Continuity) Short circuit

Resistance measurement (range set toΩ)
Measuring the internal resistance of sensors, solenoid valves
etc. to check the operating condition of components.
NOTE:

Select the appropriate range for measuring the internal
resistance, or the measurement will result in an incorrect read-
ing.

Before changing the measurement range the gauge must be
reset to zero.
8

USING A SUBARU SELECT MONITOR
With this testing procedure the defective component can be determined by directly monitoring input/output signals
of the ECM or the trouble codes.
Features

A variety of data can be checked without movements from
the drivers seat, passenger’s seat or from outside the vehicle.

This unit allows the identification of the type of malfunction,
for example whether the cause is an open or shorted wire in
the input/output signal line, or whether the breakdown of a
component is caused by a lack of maintenance.
Diagnosis

Refer to the reference values for input/output and control
data to determine whether the malfunction is caused by a worn
out component, an open wire, a short etc.

Perform the diagnostics procedure as described in chapter
“Check based on trouble codes”by monitoring the trouble
codes.
NOTE:
It will be easier to determine a malfunction if the vehicle data
for normal conditions are available for comparison.
Use of select monitor
G2H0054
1. CONNECT SELECT MONITOR.
1) Connect select monitor to data link connector located under
instrument panel (on driver’s side).
G3M0150
2) Insert cartridge into select monitor.
9

G3M0151
3) Turn ignition switch and select monitor switch ON.
4) After display is shown, press slash“/”key.
5) After AT mode is displayed, press function“[0]”.
(Display returns to AT mode when slash“/”is pressed during
on-board diagnostic operation.)
G3M0152
2. READ TROUBLE CODE SHOWN ON DISPLAY.
1) Connect select monitor.
2) Designate mode using function key.
Press [F] [B] [0] [ENT] in that order.
3) Ensure trouble code(s) is shown.
G3M0152
3. PREVIOUS TROUBLE CODE READING
1) Connect select monitor.
2) Designate mode using function key.
Press [F] [B] [1] [ENT] in that order.
3) Ensure displayed trouble code(s).
USING AN OSCILLOSCOPEA malfunction can be determined by displaying the waveforms
of input/output signals on the oscilloscope.
Diagnosis
A simple comparison of the waveforms may lead to an incor-
rect diagnosis. To exactly determine the sources of the mal-
function it will be necessary to determine them under consider-
ation about information other than waveforms.
Applying input/output signals
Connect the probe directly with the terminal of the signal.
10

Important safety notice

Providing appropriate service and repair is a matter of great importance in the serviceman’s safety maintenance
and safe operation, function and performance which the SUBARU vehicle possesses.

In case the replacement of parts or replenishment of consumables is required, genuine SUBARU parts whose
parts numbers are designated or their equivalents must be utilized.

It must be made well known that the safety of the serviceman and the safe operation of the vehicle would be
jeopardized if he used any service parts, consumables, special tools and work procedure manuals which are
not approved or designated by SUBARU.
All right reserved. This book may not be reproduced
or copied, in whole or in part, without the written
permission of FUJI HEAVY INDUSTRIES LTD.,
TOKYO JAPAN.
SUBARU,
andare trademarks of
FUJI HEAVY INDUSTRIES LTD.
© Copyright 1995 FUJI HEAVY INDUSTRIES LTD.
2