2004 SUBARU FORESTER ignition

AC-30
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
Refrigerant Leak Check
5. Refrigerant Leak Check
A: INSPECTION
1) Operate the A/C system for approx. 10 minutes,
and confirm that the high-pressure side shows at
least 690 kPa (7.03 kg/cm
2, 100 psi). Then stop the
engine to start the leak test.
2) Starting from the connection between the high-
pressure pipe and evaporator, check the system for
leaks along the high-pressure side through the
compressor. The following items must be checked
thoroughly.
3) Check the joint and seam between the pressure
switch (triple pressure switch) and high-pressure
pipe.
4) Check the connections between the condenser
and pipes, and welded joints on the condenser.
The leak tester may detect the oil on the condenser
fins as a leak.
5) Check the joint between the compressor and
hoses.
6) Check the machined area of compressor and
other joints on the compressor.
7) Check the compressor shaft seal at the area
near the center of compressor clutch pulley.
Some shaft seals show a slight amount of leakage
about 28 g (1.0 oz) per year. This is not a problem.
8) Starting from the connection between the low-
pressure pipe and evaporator, check the system for
leakage along the low-pressure side through the
compressor. The following items must be checked
thoroughly.
 Connection between two parts
 Connection between the pipe and plate
9) Visually check the rubber area of the flexible
hose for cracks.
Check the entire length of the flexible hose, espe-
cially the connection with the metal hose end.CAUTION:
Carefully check the external surface of hoses
and tubes at approx. 25 mm (0.98 in) per sec-
ond.
10) Disconnect the drain hose from the heater
case, and check the hose end for at least 10 sec-
onds.
After the test is finished, reconnect the drain hose.
11) Turn the ignition switch to ON, and run the
blower at high speed for 1 minute. Stop the blower
to check the ventilation grille on the instrument pan-
el. While moving the tester closer to the grille, run
the blower for 1 or 2 seconds, then stop it. Check
the grille at that point for at least 10 seconds.
12) Check the valve in the service port.
13) Visually check the rubber seal in the service
port cap.
AC-00035
(A) Flexible hose
AC-00036
(A)
AC-00037
AC-00038

AC-3
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
General Description
2. General Description
A: CAUTION
1) Never connect the battery in reverse polarity.
Auto A/C control module may be destroyed instant-
ly.
2) Do not disconnect the battery terminals while the
engine is running.
A large counter electromotive force will be generat-
ed in the generator, and this voltage may damage
electronic parts such as auto A/C control module,
etc.
3) Before disconnecting the connectors of each
sensor and the auto A/C control module, be sure to
turn off the ignition switch.
Auto A/C control module may be damaged.
4) Every A/C-related part is a precision part. Do not
drop them.
5) Airbag system wiring harness is routed near the
A/C control panel (auto A/C control module) and
junction box.
CAUTION:
 For airbag system, yellow-colored wiring har-
ness and connectors are all used. Do not use
the electrical test equipment on these circuits.
 Be careful not to damage the airbag system
wiring harness when servicing the A/C control
panel (auto A/C control module) and junction
box.
B: INSPECTION
Before performing the diagnosis, check the follow-
ing items which might affect A/C system problems.
1. BATTERY
1) Measure battery voltage and specific gravity of
electrolyte.
Standard voltage: 12 V
Specific gravity: More than 1.260
2) Check the condition of the fuses for A/C system
power supply and other fuses.
3) Check the condition of harness and harness
connector connections.
2. ASPIRATOR HOSE
1) Turn the ignition switch to ON, and press the A/
C switch.
2) Turn the temperature control dial at maximum
hot position.
3) Press the defroster switch.
4) Turn the fan speed control dial to 4th position.5) Approach a strip of paper (b) in front of the in-ve-
hicle sensor suction port (a) located in the instru-
ment lower cover, and check that air is being
sucked into the port by seeing the paper moving to-
wards port.
NOTE:
Be careful not to let the paper get sucked into port.
6) If the paper does not move at all, remove the in-
strument panel lower cover MOVAL, Instrument Panel Assembly.> and check
for improper connection of the aspirator hose (a),
in-vehicle sensor and heater unit, and repair them if
necessary.
3. A/C LINE
Check the connection for A/C line (A) and lower
side high-pressure pipe.
4. CONTROL LINKAGE
1) Check the state of mode door linkage.
2) Check the state of air mix door linkage.
3) Check the state of intake door linkage.
AC-00094
(a)
(a)
(b)
AC-00065
(a)
AC-00096
(A)

AC-7
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Auto A/C Control Module I/O Signal
4. Auto A/C Control Module I/O Signal
A: ELECTRICAL SPECIFICATION
Terminal No. Content Measuring conditionSpecified
value
B9
Mode door actuator power supplyChanges outlet from VENT to DEF.
*2
B8 Changes outlet from DEF to VENT.
B7
Air mix door actuator power supplyChanges air mix door from COOL to HOT.
*1
B6 Changes air mix door from HOT to COOL.
B5 IGN power supply Ignition switch: ON Battery voltage
B4 Battery power supply Ignition switch: OFF, ACC, ON Battery voltage
B3 Sunload sensorIgnition switch: ON and under normal sunload
(without sunload: 5 V)3 V
B2 Evaporator sensor Ignition switch: ON 5 V or less
B1 Air mix door actuator P.B.R. signalAir mix door: COOL position 0.5 V
Air mix door: HOT position 4.5 V
B20
Intake door actuator signalAir inlet: FRESH (other positions: 12 V) 0 V
B19 Air inlet: MIX (other positions: 12 V) 0 V
B18 Air inlet: RECIRC (other positions: 12 V) 0 V
B17 A/C ON signal A/C: ON (A/C OFF: 0 V) 8 — 10 V
B16 Blower motor control *3 *3
B15 Blower fan ON signalWhen blower fan running (when blower fan not
running: 12 V)0 V
B13 Engine coolant temperature sensor When the engine coolant is at 49°C (120°F) 8.9 V
B12 In-vehicle sensor — —
B11 Ground When there is continuity to chassis ground 0 Ω
A7 Air mix door actuator P.B.R. reference voltage Ignition switch: ON 5 V
A5 Mode door actuator position detection signal OutletBI-LEVEL, DEF 5 V
VENT, HEAT, DEF/HEAT 0 V
A4 Mode door actuator position detection signal OutletHEAT, DEF/HEAT, DEF 5 V
VENT, BI-LEVEL 0 V
A1 Illumination power supplyIgnition switch: ON, light switch: ON Battery voltage
Ignition switch: ON, light switch: OFF 0 V
A16 Sensor ground When there is continuity to chassis ground 0 Ω
AC-00099
1 2 3 4 5 6 7 8 910
11 12 13 14 15 16 17 18 19 201 2 3 4 5 6 7 8
9
10 11 12 13 14 15 16
i48B: To A:To
i49

AC-10
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Chart for Self-Diagnosis
Step Check Yes No
1 SELECT CONTROL PANEL TO SELF-DIAG-
NOSIS MODE.
1) Turn the ignition switch to OFF.
2) Start the engine while pressing defroster
switch and A/C switch.
N
OTE:
Self-diagnosis can also be performed with the
ignition switch ON, but start the engine be-
cause telling the magnet clutch operation is dif-
ficult.
3) The LED in A/C control panel blinks.Does the self-diagnosis mode
operate?Go to step 2. C OR SELF-DIAG-
NOSIS SYS-
TEMS DO NOT
OPERATE, Diag-
nostics for A/C
System Malfunc-
tion.>
2 CHECK LED ILLUMINATION.
Make sure that three LED blink in turn on A/C
control panel (5 patterns are repeated 2 times).Do all LED blink? Go to step 3.Go to step 5.
3 CHECK SENSORS MALFUNCTION.
1) After completing the LED check or when
AUTO switch is pressed, the A/C switch LED
illuminates, and then the sensor check is
started.
2) Check the input signal of each sensor in
turn. If there are any trouble for each sensor,
DEF, MODE and fan speed LEDs are blinked.
Also check for each sensor is possible respec-
tively every time AUTO switch is pressed. (At
this time, the AUTO switch LED illuminates.)
3) If there is no trouble, DEF, MODE and fan
speed LEDs are turned off.
N
OTE:
Rear window defogger LED illuminates in case
of stored malfunction but does not illuminate in
case of present malfunction.Does each DEF, MODE and
fan speed LED turn off?Go to step 4.Confirm the com-
bination of illumi-
nating LEDs by
using Sensor
Check Table, and
identify the mal-
functioning sensor
before repairing.
SENSOR CHECK
TABLE, OPERA-
TION, Diagnostic
Chart for Self-
Diagnosis.>
4 CHECK OPERATION OF EACH ACTUATOR,
COMPRESSOR AND FAN MOTOR.
1) Press the FRESH/RECIRC switch
(FRESH/RECIRC switch LED illuminates at
this time.).
2) Refer to OPERATING MODE TABLE to
check the operation of each actuator, compres-
sor and fan motor. ING MODE TABLE, OPERATION, Diagnostic
Chart for Self-Diagnosis.>
Also check for each step is possible respec-
tively every time AUTO switch pressed. (At this
time, the AUTO switch LED illuminates.)Does each actuator, compres-
sor and fan motor operate
according to operating mode
table?Press the OFF
switch or turn the
ignition switch to
OFF and finish the
self-diagnosis
mode.Refer to each
diagnostics chart
for actuator, com-
pressor and fan
motor, and repair
the malfunctioning
par t as necessary.
Diagnostics for A/
C System Mal-
function.> AC-21, Diagnostic
Procedure for
Actuators.>
5 CHECK POOR CONTACT.
Check the auto A/C control module connector
for poor contact.Is there a poor contact in con-
nector?Replace the auto
A/C control mod-
ule.Repair the con-
nector.

AC-12
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostics for A/C System Malfunction
6. Diagnostics for A/C System Malfunction
A: A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE
TROUBLE SYMPTOM:
 Switch LEDs are faulty and switches do not operate.
 Self-diagnosis system does not operate.
WIRING DIAGRAM:
AC-00149
A:
i48B:
i49B201
12345678
910 11 12 13 14 15 1612345678910
11 12 13 14 15 16 17 18 19 20
E
A:
i48B:
i49
i40
B201
SBF-1BATTERY IGNITION
SWITCH
AUTO A/C CONTROL MODULE
M/B NO.2SBF-4
F/B NO.17
B5B4B11
3
4 128910 11
12 13 14 15 16 17 18 19 20 21 22 23 2456 7
B202
3
4 128910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
LHD
14
4
10
19 2113RHD
: LHD MODEL
: RHD MODELLHD
RHD
: LHD
: LHD
B202: RHD
i41: RHD

AC-13
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostics for A/C System Malfunction
Step Check Yes No
1 CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse No. 2 from main fuse box.
3) Check the condition of fuse.Is the fuse blown-out? Replace the fuse. Go to step 2.
2 CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse No. 17 from fuse & relay
box.
3) Check the condition of fuse.Is the fuse blown-out? Replace the fuse. Go to step 3.
3 CHECK AUTO A/C CONTROL MODULE
POWER CIRCUIT.
1) Pull out the auto A/C control module con-
nector.
2) Measure the voltage between auto A/C
control module connector terminal and chassis
ground after turning the ignition switch to OFF
position.
Connector & terminal
(i49) No. 4 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 4.Check open or
short circuit in har-
ness between auto
A/C control mod-
ule and fuse.
4 CHECK AUTO A/C CONTROL MODULE
POWER CIRCUIT.
Measure the voltage between auto A/C control
module connector terminal and chassis ground
after turning the ignition switch to ON position.
Connector & terminal
(i49) No. 5 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 5.Check open or
short circuit in har-
ness between auto
A/C control mod-
ule and fuse.
5 CHECK AUTO A/C CONTROL MODULE
GROUND CIRCUIT.
Measure the resistance in harness between
auto A/C control module and chassis ground.
Connector & terminal
(i49) No. 11 — Chassis ground:Is the resistance less than 1
Ω?Go to step 6.Repair the har-
ness for ground
line.
6 CHECK POOR CONTACT.
Check poor contact in auto A/C control module
connector.Is there poor contact in con-
nector?Repair the con-
nector.Replace the auto
A/C control mod-
ule.

AC-14
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostics for A/C System Malfunction
B: BLOWER FAN DOES NOT ROTATE.
TROUBLE SYMPTOM:
 Blower motor does not rotate.
 Blower motor does not change.
WIRING DIAGRAM:
AC-00150
E
B50
B50B87A:
i48B:
i49 4
312
B87 5
21
SBF-1SBF-3 F/B NO.1
SBF-4
F/B NO.2
F/B NO.17
B16B15
18
B202
B202
i41
22
341212345612345678
910 11 12 13 14 15 1612345678910
11 12 13 14 15 16 17 18 19 20
34 12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
A: i48B: i49BATTERY
IGNITION
SWITCH
BLOWER
MOTOR RELAY
BLOWER MOTOR
B201
34 12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 2456 7
3
RHDRHD
LHDLHD
: LHD MODEL
: RHD MODELLHD
RHD
B201i40
AUTO A/C CONTROL MODULE

AC-15
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostics for A/C System Malfunction
Step Check Yes No
1 CHECK FUSE.
1) Remove the fuse No. 1, 2 and 17 from fuse
& relay box.
2) Check the condition of fuse.Is any fuse blown-out? Replace the fuse. Go to step 2.
2 CHECK POWER SUPPLY FOR BLOWER
MOTOR.
1) Turn the ignition switch to ON.
2) Turn the fan speed control dial clockwise.
3) Measure the voltage between blower motor
and chassis ground.
Connector & terminal
(B87) No. 1 (+) — Chassis ground (
−):Is the voltage more than 8 V (at
normal temperature)?Go to step 3.Repair the open
circuit of blower
motor power sup-
ply line harness.
3 CHECK BLOWER MOTOR RELAY.
1) Turn the ignition switch to OFF.
2) Remove the blower motor relay.
3) Connect the battery positive (+) terminal to
terminal No. 1 of blower motor relay, and nega-
tive (−) terminal to terminal No. 3.
4) Measure the resistance between terminals
No. 2 and 4.
Te r m i n a l s
No. 2 — No. 4:Is the resistance less than 1
Ω?Go to step 4.Replace the
blower motor relay.
4 CHECK BLOWER MOTOR.
1) Disconnect the connector from blower
motor.
2) Connect the battery positive (+) terminal to
terminal No. 1 of blower motor connector, and
negative (−) terminal to terminal No. 2 and No.
5.
3) Make sure the blower motor runs.Does the blower motor run? Go to step 5.Replace the
blower motor.
5 CHECK POOR CONTACT.
Check poor contact in auto A/C control module
connector.Is there poor contact in con-
nector?Repair the con-
nector.Replace the auto
A/C control mod-
ule.