sensor SUBARU FORESTER 2004 Service User Guide

AC-6
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Electrical Component Location
2. PASSENGER COMPARTMENT
(1) Mode door actuator (4) Intake door actuator (7) Air mix door actuator
(2) In-vehicle sensor (5) Blower motor
(3) Sunload sensor (6) Evaporator sensor
AC-00098
(1) (6)(4)
(5) (7)(7)(6)(5) (4) (3)
(1) (2)
(3)

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-9
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Chart for Self-Diagnosis
5. Diagnostic Chart for Self-Diagnosis
A: OPERATION
(1) Temperature control dial (4) A/C switch (7) Rear window defogger switch
(2) OFF/BRIGHT switch (5) Defroster switch (8) FRESH/RECIRC switch
(3) AUTO switch (6) Air flow control switch (9) Fan speed control dial
(1) Normal Operation (6) After the LED display (Approx. 20
sec.)(9) Output Equipment Operation
(Sequential Operation)
(2) Switch
(3) IG OFF → ON with pressing (7) Sensor Check (Sequential Opera-
tion)(10) Output Equipment Operation
(Phased Operation)
(4) Self-Diagnosis Mode
(5) LED Display Check (8) Sensor Check (Phased Operation)
AC-00250
(5)
(6)(7)
(8) (9) (4)
(3)
(2)
(1)
AC-00242
OFF
AUTO
AUTO
AUTO
AUTOAUTO
(5)(4) (3)
DEF A / C+
A / CA / C
A / C A / C
(6)
(7)
(8)(9)
(10)
FRESH / RECIRCFRESH / RECIRCFRESH / RECIRC
FRESH / RECIRC:
(2)
(1)

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-11
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Chart for Self-Diagnosis
1. SENSOR CHECK TABLE
NOTE:
When the sunload sensor is checked indoors or in the shade, open circuit might be indicated. Always check
the sunload sensor at a place where sun shines directly on it.
*1: Only present malfunction is indicated for open circuit of sunload sensor. (However, stored malfunction can be indicated for
short circuit of sunload sensor.)
2. OPERATING MODE TABLE
Diag-
nostic
stepsChecked sensorOpen circuit Short circuitPresent
malfunctionStored
malfunction
DEF LEDMODE/FAN
LEDDEF LEDMODE/FAN
LEDREAR WINDOW
DEFOGGER LED
1 In-vehicle sensor
Tu r n o f fVENT
LED blinks
IlluminateVENT
LED blinks
Turn off Illuminate 2 Ambient sensorBI-LEVEL
LED blinksBI-LEVEL
LED blinks
3 Evaporator sensorHEAT
LED blinksHEAT
LED blinks
4 Sunload sensor*1DEF/HEAT
LED blinksDEF/HEAT
LED blinks
5 Air mix door actuator P.B.R.Fan speed
1st
LED blinksFan speed
1st
LED blinks
6Combination meter commu-
nication (Ambient sensor)Fan speed
2nd
LED blinksFan speed
2nd
LED blinks
When all parts are in good condition Turn off
Step 12345678
Illuminating LEDVENT
LEDBI-LEVEL
VENTHEAT LEDDEF/HEAT
LEDFan speed
1st LEDFan speed
2nd LEDFan speed
3rd LEDFan speed
4th LED
Fan speed LO LO ML ML ML MH MH HI
Mode actuator VENT VENT VENT BI-LEVEL HEAT HEAT DEF/HEAT DEF
Intake actuator FRESH RECIRC RECIRC FRESH FRESH FRESH FRESH FRESH
Air mix door actuatorFULL
COOL
(0%)FULL
COOL
(0%)FULL
COOL
(0%)MEDIUM
(50%)MEDIUM
(50%)FULL HOT
(100%)FULL HOT
(100%)FULL HOT
(100%)
Compressor
(magnet clutch)OFFONONONONONONON

AC-32
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Procedure for Sensors
8. Diagnostic Procedure for Sensors
A: AMBIENT SENSOR
TROUBLE SYMPTOM:
 Fan speed is not switched when the fan speed control dial is in AUTO position.
 Malfunction related to ambient sensor is indicated in self diagnosis.
WIRING DIAGRAM:
 LHD model
AC-00107
A:
i48B:
i49B:
i10
12345678
910 11 12 13 14 15 1612345678910
11 12 13 14 15 16 17 18 19 20
3
4 128910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
i41
B202
B202B38
i3
B38
B:
i10
COMBINATION
METER
A:
i48B:
i49
19
A14
24
B30
123456789101112131415161718192021222324252627282930
219
32
1234 5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25
AUTO A/C
CONTROL
MODULE
i2
B37
141521
B24
B25
12
B62F45F78AMBIENT
SENSOR
B37
3
4 12
8910 11 12 13 14 15 16567
F45
12
F78

AC-33
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Procedure for Sensors
 RHD model
AC-00884
A:
i48B:
i49B:
i10
12345678
910 11 12 13 14 15 1612345678910
11 12 13 14 15 16 17 18 19 20
3
4 128910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
i41
B202
B202
B:
i10
COMBINATION
METER
A:
i48B:
i49
3 A14
B30
123456789101112131415161718192021222324252627282930
AUTO A/C
CONTROL
MODULE
i2
B37
141521
B24
B25
1817
B100F2F78AMBIENT
SENSOR
F2
12
F78
21
1413 16
: MT MODEL
: AT MODEL
3
4 128910
11
12 13 14 15 16 17 18 19 20 21 225673
4 12 8
910 11
12 13 14 15 16 17 185
67
i2 :
i2 :
MT AT
AT
MT AT MT

AC-34
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Procedure for Sensors
Step Check Yes No
1 CHECK HARNESS CONNECTOR BETWEEN
AUTO A/C CONTROL MODULE AND COM-
BINATION METER.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from auto A/C
control module and combination meter.
3) Measure the resistance in harness
between auto A/C control module and combi-
nation meter.
Connector & terminal
(i10) No. 30 — (i48) No. 14:Is the resistance less than 1
Ω?Go to step 2.Repair the har-
ness between auto
A/C control mod-
ule and combina-
tion meter.
2 CHECK AMBIENT SENSOR CIRCUIT.
Check the ambient sensor circuit. 8, CHECK OUTSIDE TEMPERATURE INDI-
CATOR, INSPECTION, Combination Meter
System.>Is the ambient sensor circuit
normal?Go to step 3.Repair the ambi-
ent sensor circuit.
3 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 A/C
control module.

AC-35
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Procedure for Sensors
B: IN-VEHICLE SENSOR
TROUBLE SYMPTOM:
 Blower fan speed, outlet port and inlet port do not change after turning the AUTO switch to ON.
 Malfunction related to ambient sensor is indicated in self diagnosis.
WIRING DIAGRAM:
AC-00157
A:
i48B:
i49
12345678
910 11 12 13 14 15 1612345678910
11 12 13 14 15 16 17 18 19 20
i55 :
IN-VEHICLE
SENSOR
A:
i48B:
i49
A16
1
B12
2
12
AUTO A/C
CONTROL
MODULE
LHD
LHD
RHD
RHD
LHD
RHD
LHD
RHD
924
B314 :
: LHD MODEL
: RHD MODEL
LHD
RHD
LHD
RHD
LHD
RHD
i55 :
B314 :
LHD
RHD
3
4 128910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
B202
B202
i41

AC-36
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Procedure for Sensors
Step Check Yes No
1 CHECK IN-VEHICLE SENSOR.
1) Turn the ignition switch to OFF.
2) Remove the instrument panel lower cover.
3) Disconnect the connector from in-vehicle
sensor.
4) Measure the resistance between connector
terminals of in-vehicle sensor.
Te r m i n a l s
No. 1 — No. 2:Is the resistance approx. 2.7
kΩ at 20°C (68°F)?Go to step 2.Replace the in-
vehicle sensor.
2 CHECK INPUT SIGNAL FOR IN-VEHICLE
SENSOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between in-vehicle
sensor harness connector terminal and chas-
sis ground.
Connector & terminal
LHD model:
(i55) No. 2 (+) — Chassis ground (
−):
RHD model:
(B314) No. 2 (+) — Chassis ground (
−):Is the voltage approx. 5 V? Go to step 6.Go to step 3.
3 CHECK AUTO A/C CONTROL MODULE
OUTPUT SIGNAL.
1) Turn the ignition switch to OFF.
2) Remove the auto A/C control module.
3) Turn the ignition switch to ON.
4) Measure the voltage between connector
terminals of auto A/C control module.
Connector & terminal
(i49) No. 12 (+) — (i48) No. 16:Is the voltage approx. 5 V? Go to step 4.Go to step 6.
4 CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND IN-VEHICLE SEN-
SOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from auto A/C
control module.
3) Measure the resistance in harness
between auto A/C control module and in-vehi-
cle sensor.
Connector & terminal
LHD model:
(i55) No. 2 — (i49) No. 12:
RHD model:
(B314) No. 2 — (i49) No. 12:Is the resistance less than 1
Ω?Go to step 5.Repair the har-
ness between auto
A/C control mod-
ule and in-vehicle
sensor.
5 CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND IN-VEHICLE SEN-
SOR.
Measure the resistance in harness between
auto A/C control module and in-vehicle sensor.
Connector & terminal
LHD model:
(i55) No. 1 — (i48) No. 16:
RHD model:
(B314) No. 1 — (i48) No. 16:Is the resistance less than 1
Ω?Go to step 6.Repair the har-
ness between auto
A/C control mod-
ule and in-vehicle
sensor.
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.