check SUBARU LEGACY 1995 Service Repair Manual

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).
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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.
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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.
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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.
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