Vacuum SUBARU LEGACY 1995 Service Owner's Manual

G4M0596
7. Evacuating and Charging
The following points should be kept in mind when evacu-
ating and charging with a manifold gauge set.
1) Be certain that goggles and gloves are worn.
2) If bulk refrigerant [13.6 kg (30 lb) canister] is used, be
certain to weigh the charge amount carefully, using the
correct equipment, to avoid overcharging the system.
3) The charging procedure described in this section
begins by chargingliquidrefrigerant into the high- pres-
sure side of the systemwith the engine off.The proce-
dure is completed by charging refrigerantvaporinto the
low-pressure side of the system with the engine running.
CAUTION:
Never open the high-pressure manifold valve when the
engine is running.
G4M0597
1. CONNECT THE GAUGE SET
1) Close the high- and low-pressure manifold valves.
2) Attach the low-pressure manifold hose to the low- pres-
sure service port on the vehicle. Check the low- pressure
gauge. If more than 68.6 kPa (0.70 kg/cm
2, 10 psi) is
indicated, discharge the system prior to charging.
3) Attach the high-pressure manifold hose to the high-
pressure service port on the vehicle.
4) Connect the center hose from the manifold to the
vacuum pump.
5) Turn on the vacuum pump.
6) Slowly open the low-pressure manifold valve.
7) When the low-pressure gauge reaches approximately
66.43 kPa (498.3 mmHg, 19.62 inHg), slowly open the
high-pressure manifold valve.
G4M0598
8) Maintain a minimum vacuum level of 100.56 kPa (754.4
mmHg, 29.70 inHg) for a minimum of 15 minutes on a new
system or 30 minutes for an in-service system.
NOTE:
The gauge will read 4 kPa (25 mmHg, 1 inHg) less for
every 304.8 m (1,000 ft) above sea level.
19
4-7SERVICE PROCEDURE
7. Evacuating and Charging

G4M0599
2. PERFORM A VACUUM LEAK TEST
1) After 15 minutes (or more) of evacuation, close the
high-pressure manifold valve.
2) Close the low-pressure manifold valve.
3) Turn off the vacuum pump.
G4M0600
4) Note the low side gauge reading.
5) After 5 minutes, re-check the low-pressure gauge read-
ing.
If the vacuum level has changed more than 4 kPa (25
mmHg, 1 inHg), perform an HFC-134a leak test.
If the vacuum reading is about the same as noted in step
2-4), continue on to step 2-6).
G4M0980
6) Carefully attach the can tap to the refrigerant can by
following the can tap manufacturer’s instructions.
7) Disconnect the center manifold hose from the vacuum
pump and connect the hose to the tap valve.
G4M0981
8) If a 13.6 kg (30 lb) container of refrigerant is used a
weight scale will be needed. This scale is to determine the
amount of refrigerant that is used.
Connect the center hose from the manifold to the valve.
Place the 13.6 kg (30 lb) container on the scale, valve end
down.
G4M0603
3. PURGE THE CENTER HOSE
1) Verify that all three hose connections are tight at the
manifold gauge set.
2) Open the valve on the HFC-134a source.
3)With safety equipment in place (goggles and
gloves), use extreme cautionand loosen the center hose
connection at the manifold and allow the HFC-134a to
escape for no more than two or three seconds, then quickly
retighten the hose fitting at the manifold.
20
4-7SERVICE PROCEDURE
7. Evacuating and Charging

Condition Probable cause Corrective action
G4M0676
G4M0677
Insufficient cooling;
Sweated suction line.
No cooling;
Sweating or frosted suc-
tion line.Expansion valve allows
too much refrigerant
through evaporator.
Faulty seal of O-ring in
expansion valve.Check valve for opera-
tion. If suction side does
not show a pressure
decrease, replace valve.
1. Discharge system.
2. Remove expansion
valve and replace
O-ring.
3. Evacuate and
replace system.
AIR IN SYSTEM
G4M0678
Insufficient cooling Air mixed with refriger-
ant in system.1. Discharge system.
2. Replace receiver
drier.
3. Evacuate and charge
system.
MOISTURE IN SYSTEM
G4M0679
After operation for a
while, pressure on suc-
tion side may show
vacuum pressure read-
ing. During this
condition, discharge air
will be warm. As warn-
ing of this, reading
shows 39 kPa (0.4
kg/cm
2, 6 psi) vibration.Drier is saturated with
moisture. Moisture has
frozen at expansion
valve. Refrigerant flow
is restricted.1. Discharge system.
2. Replace receiver
drier (twice if neces-
sary).
3. Evacuate system
completely. (repeat
30-minute evacuating
three times.)
4. Recharge system.
45
4-7DIAGNOSTICS
2. Performance Test Diagnosis

B6M0358
3) Remove nuts which secure actuator.
4) Remove actuator while disconnecting vacuum hose.
Tightening torque:
7.4±1.5 N⋅m (0.75±0.15 kg-m, 5.4±1.1 ft-lb)
B6M0359A
4. VACUUM PUMP AND VALVES
1) Disconnect connector from vacuum pump.
2) Remove bolts which secure vacuum pump.
3) Remove A/C receiver/drier bracket.
4) Remove vacuum pump while disconnecting vacuum
hose.
Tightening torque:
7.4±1.5 N⋅m (0.75±0.15 kg-m, 5.4±1.1 ft-lb)
5. STOP AND BRAKE SWITCH
Refer to 4-5 [C101 (MT) or C201 (AT)] as for removal and
installation of stop and brake switch.
6. CLUTCH SWITCH (MT)
Refer to 4-5 [C101] as for removal and installation of clutch
switch.
7. INHIBITOR SWITCH (AT)
Refer to 3-2 [W4A4] as for removal and installation of
inhibitor switch.
B6M0360A
8. CRUISE CONTROL MODULE
1) Follow the same preparatory procedures when remov-
ing door lock timer.
2) Remove nuts which secure cruise control module, and
remove cruise control module from bracket while pulling
right side lower end of instrument panel.
CAUTION:
Be careful not to damage instrument panel while pull-
ing its right side lower end.
3) Disconnect connector from cruise control module.
4) Installation is the reverse order of removal.
49
6-2SERVICE PROCEDURE
21. Cruise Control

OBD0170
E: DTC P0106
—PRESSURE SENSOR CIRCUIT
RANGE/PERFORMANCE PROBLEM (P
—R)—
DESCRIPTION:
Refer to“D: DTC P0105—PRESSURE SENSOR CIR-
CUIT MALFUNCTION—[T11D0]”.
DTC DETECTING CONDITION:

Two consecutive trips with fault
1.Check transmission type.
AT
MT
Check AT/MT identification circuit.
2.Check DTC P0105 or P1102 on display.
No
Ye s

Inspect DTC P0105 or P1102 using“11. Diagnostics
Chart with Trouble Code [T1100]”.

In this case, it is unnecessary to inspect DTC
P0106.
3.Check data for control.
4.Check vacuum hose.
5.Check pressure sources of switching solenoid
valve.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES. [T3D0] and [T3E0].>




151
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

4
CHECK VACUUM HOSE.
: Check for disconnection, holes, or clogging
of the vacuum hoses.
NOTE:
Check the hoses;

From pressure sources switching solenoid valve to
intake manifold.

From pressure sensor to pressure sources switching
solenoid valve.
: Repair hoses.
: Go to step 5.
5CHECK PRESSURE SOURCES OF SWITCH-
ING SOLENOID VALVE.
1) Turn ignition switch to OFF.
2) Connect test mode connector.
3) Turn ignition switch to ON.
: Is operation sound of the pressure sources
solenoid valve heard? (ON↔OFF each 1.5
sec.)
: Replace pressure sensor.
: Replace pressure sources switching solenoid
valve.
155
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0711
3) Disconnect fuel delivery hose from fuel filter, and con-
nect fuel pressure gauge.
G2M0348
4) Start the engine and idle while gear position is neutral.
5) Measure fuel pressure while disconnecting pressure
regulator vacuum hose from intake manifold.
: Fuel pressure:
226—275 kPa (2.3—2.8 kg/cm2,
33—40 psi)
: Go to next step.
: Repair the following items.
Fuel pressure too high
Clogged fuel return line or bent
hose
Fuel pressure too low
Improper fuel pump discharge

Clogged fuel supply line
6) After connecting pressure regulator vacuum hose, mea-
sure fuel pressure.
: Fuel pressure:
157—206 kPa (1.6—2.1 kg/cm2,
23—30 psi)
: Go to step 4.
: Repair the following items.
Fuel pressure too high
Faulty pressure regulator

Clogged fuel return line or bent
hose
Fuel pressure too low
Faulty pressure regulator

Improper fuel pump discharge

Clogged fuel supply line
WARNING:
Before removing fuel pressure gauge, release fuel
pressure.
NOTE:

If fuel pressure does not increase, squeeze fuel return
hose 2 to 3 times, then measure fuel pressure again.

If out of specification as measured at step 6), check or
replace pressure regulator and pressure regulator vacuum
hose.
200
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0315
AB: DTC P0400
—EXHAUST GAS RECIRCULATION FLOW
MALFUNCTION (EGR)—
DESCRIPTION:

The EGR system aims at reduction of NOx by lowering
the combustion temperature through recirculation of a part
of exhaust gas into cylinders via the intake manifold.

This system consists of the EGR valve, the EGR sole-
noid valve and BPT (Back Pressure Transducer). The EGR
valve is operated by the vacuum pressure from throttle
body via BPT and controls the exhaust gas flow from the
exhaust manifold to the intake manifold by open/close
operation of the EGR valve.
The EGR solenoid valve is controlled by the ECM accord-
ing to the engine driving condition and opens/closes the
vacuum line from the BPT to the EGR valve diaphragm.
The BPT controls the vacuum pressure to control the
amount of EGR according to the engine load.
OBD0316A
229
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0317A

The EGR valve is situated between the exhaust manifold
and intake manifold. After opening EGR solenoid valve,
EGR valve is opened for receiving throttle port pressure on
diaphragm. Then, part of the exhaust gas is recirculated
into intake manifold.
DTC DETECTING CONDITION:

Two consecutive trips with fault
TROUBLE SYMPTOM:

Poor driving performance on low engine speed
1.Check transmission type.
AT
MT
Check AT/MT identification circuit. [T11BN0].>
2.Check DTC P0105, P0106, P0403, P1102 on
display.

3.Check vacuum hose.
4.Check operation of EGR system.
Confirmation of actual driving
pattern
CAUTION:
Before confirmation of actual driving pattern, conduct
CLEAR MEMORY and INSPECTION MODES. [T3D0] and [T3E0].>




230
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

3
CHECK VACUUM HOSE.
: Check vacuum hoses for disconnection,
leakage and clogging.
: Check and repair the following items.

Two lines of pipes and hoses running between
throttle body and BPT

Pipe and hose line connecting BPT and EGR
solenoid valve

Hose between EGR solenoid valve and EGR
valve

BPT pressure transmitting hose
: Go to step 4.
4
CHECK OPERATION OF EGR SYSTEM.
1) Turn ignition switch to OFF.
2) Connect the test mode connector.
3) Turn ignition switch to ON.
: Does EGR solenoid valve produce operating
sound?
: Replace EGR solenoid valve.
: Go to next step.
4) Turn ignition switch to OFF.
5) Disconnect connector from EGR solenoid valve.
6) Connect 12 V battery’s ground
terminal to one ter-
minal of the EGR solenoid valve. Then connect 12 V bat-
tery’sterminal to the other terminal of it.
CAUTION:
Do not use the 12 V battery installed in the vehicle,
because the electrical system may be damaged.
7) Start the engine.
: Open throttle valve by 5 to 10 degrees and
visually check EGR valve operation.
: Possibly EGR valve malfunction may be due to
freezing or clogging by foreign matter. At this point
in time do not replace EGR valve, since it is not
faulty. And after the checking, go to
CONFIR-
MATION OF ACTUAL DRIVING PATTERN.
NOTE:
If malfunction is detected again in the confirmation of actual
driving pattern, EGR valve is faulty. Go to next
.
: Go to next.
233
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code