2002 MAZDA 6 climate control

U–1
U
UHEATER AND AIR CONDITIONER SYSTEMS
OUTLINE................................................................ U-2
OUTLINE OF CONSTRUCTION.......................... U-2
FEATURES .......................................................... U-2
SPECIFICATIONS ............................................... U-2
CONTROL SYSTEM............................................... U-6
WATER HEATER SYSTEM................................. U-6
OUTLINE................................................................ U-7
SUPPLEMENTAL SERVICE INFORMATION .....U-7
LOCATION INDEX.................................................U-8
BASIC SYSTEM................................................... U-8
CONTROL SYSTEM ............................................ U-9
BASIC SYSTEM................................................... U-10
A/C UNIT REMOVAL/INSTALLATION...............U-10
A/C COMPRESSOR
REMOVAL/INSTALLATION ............................U-11
CONDENSER REMOVAL/INSTALLATION ....... U-12
REFRIGERANT LINES
REMOVAL/INSTALLATION ............................U-13
CONTROL SYSTEM............................................. U-15
WATER HEATER UNIT
REMOVAL/INSTALLATION ............................U-15
FUEL PUMP (WATER HEATER SYSTEM)
INSPECTION .................................................. U-16
CLIMATE CONTROL UNIT INSPECTION.........U-16
ON-BOARD DIAGNOSTIC...................................U-22
FOREWORD ......................................................U-22
DTC TABLE ................................................... U-22-2
PID/DATA MONITOR AND RECORD ........... U-22-2
DTC B1317 .................................................... U-22-3
DTC B1318 ........................................................ U-23
DTC B1342, B2463, B2537, B2538, B2547 ....... U-23
DTC B2449, B2450 ............................................ U-24
DTC B2451, B2452 ............................................ U-24
DTC B2453, B2454 ............................................ U-25
DTC B2548 ........................................................ U-25
TROUBLESHOOTING.......................................... U-26
FOREWORD ......................................................U-26
TROUBLESHOOTING INDEX ...........................U-26 FEATURES
SERVICE

OUTLINE
U–7
U
SUPPLEMENTAL SERVICE INFORMATIONA6E850201038204•The following additions have been made for the MZR-CD (RF Turbo) since the publication of the Mazda6
Workshop Manual (1730-1*-02C).
A/C unit
•Removal/installation procedure has been modified.
A/C compressor
•Removal/installation procedure has been modified.
Condenser
•Removal/installation procedure has been modified.
Refrigerant lines
•Removal/installation procedure has been modified.
Water heater unit
•Removal/installation procedure has been added.
Fuel pump (water heater system)
•Inspection procedure has been added.
Climate control unit
•Inspection procedure has been modified.
Water heater system
•On-board diagnostic system has been added.
End Of Sie
OUTLINE

LOCATION INDEX
U–9
U
CONTROL SYSTEMA6E850001040202
.
End Of Sie
1
2
3
A6E85002003
1 Water heater unit
(See U–15 WATER HEATER UNIT REMOVAL/
INSTALLATION)
2 Fuel pump (water heater system)
(See U–16 FUEL PUMP (WATER HEATER
SYSTEM) INSPECTION)3 Climate control unit
(See U–16 CLIMATE CONTROL UNIT
INSPECTION)

U–16
CONTROL SYSTEM
FUEL PUMP (WATER HEATER SYSTEM) INSPECTIONA6E8540133502011. Inspect for continuity between fuel pump terminal
A and B using an ohmmeter.
•If not as specified, replace the fuel pump
(water heater system).
End Of Sie
CLIMATE CONTROL UNIT INSPECTIONA6E854061190201Full-auto Air Conditioner
1. Connect the all center panel connectors.
2. Turn the ignition switch to ON position.
3. Measure the voltage at each climate control unit terminal and refer to the terminal voltage list.
•If not as specified, inspect the parts listed under “Action” and the related wiring harness.
—If there is any malfunction, replace the climate control unit.
Terminal Voltage List (Reference)
AME8540W007
Terminal Signal Connected to Test condition Voltage (V) Action
1A Blower motor
feedback signal•Blower motor
•Power MOS
FETFan switch is OFF 12 1. Inspect for continuity or
short circuit (Climate control
unit—blower motor: 1A—B)
(Climate control unit—power
MOS FET: 1A—B, 1C—E)
(Blower motor—blower
relay: A—C) (Blower relay—
fuse: D—BLOWER 40 A
fuse)
2. Inspect for continuity (Power
MOS FET—ground: A—
GND) (Blower relay—
ground: A—GND)
3. Inspect power MOS FET
4. Inspect blower motor
5. Inspect blower relay
6. Inspect BLOWER 40 A fuse
7. Replace power MOS FET Fan switch is at manual
LO7.8
Fan switch is at manual
HI
0.2
2A
1W
2B 2C
2D 2E
2F 2G
2H 2I 2K
2L
* 1A
1B
* *
* *
* 1X1C 1E
1F * 1I
1K
1M 1O
1P 1Q 1S
1T 1U
1J 1L
A6E85402001

CONTROL SYSTEM
U–17
U
1B +5 V•Air mix actuator
•Airflow mode
actuator
•Solar radiation
sensorIgnition switch at ON
position
5.0•Inspect for short circuit
(Climate control unit— air
mix actuator, airflow mode
actuator, solar radiation
sensor: 1B—B, B, A)
•Inspect air mix actuator
•Inspect airflow mode
actuator
•Inspect solar radiation
sensor
•Inspect terminal voltage of
climate control unit
connector (2H, 2L)
Ignition switch at LOCK
positionBelow 1.0•Replace climate control unit
1C Blower motor
control signalPower MOS FET Fan switch is OFF Below 1.0•Inspect terminal voltage of
climate control unit (1A)
Fan switch is at manual
LO4.1
Fan switch is at manual
HI7.9
1D—— —— —
1E Rear window
defroster SW
signalRear window
defroster relayRear window defroster
switch is off
12•Inspect for continuity or
short circuit (Climate control
unit—rear window defroster
relay: 1E—E)
•Inspect rear window
defroster relay
Rear window defroster
switch is on Below 1.0•Inspect terminal voltage of
climate control unit (2H, 2L)
•Inspect center panel
1F On-board
diagnostic signalA/C check
connectorTerminal A of A/C check
connector is shorted. Below 1.0•Inspect for continuity
(Climate control unit—A/C
check connector: 1F—A)
Other
5.4•Inspect short circuit (Climate
control unit—A/C check
connector: 1F—A)
•Inspect terminal voltage of
climate control unit (2H, 2L)
1G—— —— —
1H—— —— —
1I GND•Cabin
temperature
sensor
•Evaporator
temperature
sensor
•Ambient
temperature
sensor
•Water
temperature
sensor
•Air mix actuator
•Airflow mode
actuatorUnder any condition
Below 1.0•Inspect terminal voltage of
climate control unit (2L)
1J Water heater
selectGround Under any condition
Below 1.0•Inspect for continuity
(Climate control unit—
ground: 1J—GND)
•Inspect center panel Terminal Signal Connected to Test condition Voltage (V) Action

U–18
CONTROL SYSTEM
1K Ambient
temperature
sensor inputAmbient
temperature sensorDepends on temperature
surrounding sensor
See Figure
2•Inspect for continuity
(Climate control unit—
ambient temperature
sensor: 1K—B, 1I—A)
•Inspect for short circuit
(Climate control unit—
ambient temperature
sensor: 1K—B)
•Inspect ambient
temperature sensor
•Inspect terminal voltage of
climate control unit (2H, 2L)
1L MZR-CD (RF
Turbo) selectGround Under any condition
Below 1.0•Inspect for continuity
(Climate control unit—
ground: 1L—GND)
•Inspect center panel
1M Cabin
temperature
sensor inputCabin temperature
sensorDepends on temperature
surrounding sensor
See Figure
3•Inspect for continuity
(Climate control unit— cabin
temperature sensor: 1M—B,
1I—A)
•Inspect for short circuit
(Climate control unit— cabin
temperature sensor: 1M—B)
•Inspect cabin temperature
sensor
•Inspect terminal voltage of
climate control unit (2H, 2L)
1N—— —— —
1O Water
temperature
sensor inputWater temperature
sensorDepends on temperature
surrounding sensor
See Figure
4•Inspect for continuity
(Climate control unit—water
temperature sensor: 1O—A,
1I—B)
•Inspect for short circuit
(Climate control unit—water
temperature sensor: 1O—A)
•Inspect water temperature
sensor
•Inspect terminal voltage of
climate control unit (2H, 2L)
1P A/C Refrigerant
pressure switchFan switch at OFF
12•Inspect for continuity or
short circuit (Climate control
unit—refrigerant pressure
switch: 1P—A) (Refrigerant
pressure switch—PCM: B—
1AC (except MZR-CD (RF
Turbo)), 84 (MZR-CD (RF
Turbo)))
•Inspect refrigerant pressure
switch
•Inspect PCM terminal
voltage (1AC (except MZR-
CD (RF Turbo)), 84 (MZR-
CD (RF Turbo)))
(See F1–33 PCM
INSPECTION (4WD) )
(See F2–65 PCM
INSPECTION )
Fan switch at 1st
position, A/C switch ONBelow 1.0•Inspect terminal voltage of
climate control unit (2H, 2L) Terminal Signal Connected to Test condition Voltage (V) Action

CONTROL SYSTEM
U–19
U
1Q Evaporator
temperature
sensor input
signalEvaporator
temperature sensorDepends on temperature
surrounding sensor
See Figure
1•Inspect for continuity
(Climate control unit—
evaporator temperature
sensor: 1Q—B, 1I—A)
•Inspect for short circuit
(Climate control unit—
evaporator temperature
sensor: 1Q—B)
•Inspect evaporator
temperature sensor
•Inspect terminal voltage of
climate control unit (2H, 2L)
1R—— —— —
1S Solar radiation
sensor inputSolar radiation
sensorIncandescent light (60W)
shining on solar
radiation sensor from
distance of approx.
100mm {3.9 in}4.0•Inspect for continuity or
short circuit (Climate control
unit—solar radiation sensor:
1S—B, 1B—A)
•Inspect terminal voltage of
climate control unit (1B)
•Inspect solar radiation
sensor Light to solar radiation
sensor blockBelow 1.0
1T GND Ground Under any condition
Below 1.0•Inspect for continuity
(Climate control unit—
ground: 1T—GND)
•Inspect center panel
1U Potentiometer
signalAir mix actuator Set temperature at MAX
COLD0.6•Inspect for continuity or
short circuit (Climate control
unit—air mix actuator: 1U—
C)
•Inspect air mix actuator
•Inspect terminal voltage of
climate control unit (1B) Set temperature at MAX
HOT
4.3
1V—— —— —
1W Potentiometer
signalAirflow mode
actuatorVENT mode 4.3•Inspect for continuity or
short circuit (Climate control
unit—airflow mode actuator:
1W—C)
•Inspect airflow mode
actuator
•Inspect terminal voltage of
climate control unit (1B) BI-LEVEL mode 3.3
HEAT mode 2.3
HEAT/DEF mode 1.5
DEFROSTER mode
0.6
1X Hazard warning
SW signalHazard warning
switchHazard warning switch is
off
12•Inspect for continuity or
short circuit (Climate control
unit—flasher unit: 1X—H)
•Inspect flasher unit
Hazard warning switch is
on Below 1.0•Inspect terminal voltage of
climate control unit (1T)
•Inspect center panel
2A Panel light control
signalPanel light control
switchHeadlight switch ON and
panel light control switch
at max. illumination
0.2•Inspect for continuity
(Climate control unit— panel
light control switch: 2A—C)
(Panel light control switch—
ground: C—GND)
•Inspect panel light control
switch
Headlight switch ON and
panel light control switch
at min. illumination10.2•Inspect for short circuit
(Climate control unit— panel
light control switch: 2A—C) Terminal Signal Connected to Test condition Voltage (V) Action

U–20
CONTROL SYSTEM
2B TNS signal TNS relay Headlight switch OFF
Below 1.0•Inspect for short circuit
(Climate control unit—TNS
relay: 2B—D)
•Inspect TNS relay
•Inspect headlight switch
Headlight switch ON
12•Inspect for continuity or
short circuit (Climate control
unit—TNS relay: 2B—D)
•Inspect TNS relay
•Inspect headlight switch
2C Motor drive signal Air mix actuator Moving to COLD 12•Inspect for continuity or
short circuit (Climate control
unit—air mix actuator: 2D—
D, 2C—F)
•Inspect air mix actuator Moving to HOT
Below 1.0
2D Motor drive signal Air mix actuator Moving to HOT 12•Inspect for continuity or
short circuit (Climate control
unit—air mix actuator: 2C—
F, 2D—D)
•Inspect air mix actuator Moving to COLD
Below 1.0
2E Motor drive signal Airflow mode
actuatorMoving to DEFROSTER 12•Inspect for continuity or
short circuit (Climate control
unit—airflow mode actuator:
2E—F, 2G—D)
•Inspect airflow mode
actuator Moving to VENT
Below 1.0
2F Backup power
supply ROOM 15 A fuse Under any condition
B+•Inspect for continuity or
short circuit (Climate control
unit—fuse: 2F— ROOM 15
A fuse)
•Inspect ROOM 15 A fuse
2G Motor drive signal Airflow mode
actuatorMoving to VENT 12•Inspect for continuity or
short circuit (Climate control
unit—airflow mode actuator:
2G—D, 2E—F)
•Inspect airflow mode
actuator Moving to DEFROSTER
Below 1.0
2H IG2 A/C 15 A fuse Ignition switch at ON
position
B+•Inspect for continuity or
short circuit (Climate control
unit—fuse: 2H—A/C 15 A
fuse)
•Inspect A/C 15 A fuse
Ignition switch at LOCK
position Below 1.0•Inspect for short circuit
(Climate control unit—fuse:
2H—A/C 15 A fuse)
2I Motor drive signal Air intake actuator Moving to
RECIRCULATE12•Inspect for continuity or
short circuit (Climate control
unit—air intake actuator:
2I—F, 2K—D)
•Inspect air intake actuator Moving to FRESH
Below 1.0
2J—— —— —
2K Motor drive signal Air intake actuator Moving to FRESH 12•Inspect for continuity or
short circuit (Climate control
unit—air intake actuator:
2K—D, 2I—F)
•Inspect air intake actuator Moving to
RECIRCULATE
Below 1.0
2L GND Ground Under any condition
Below 1.0•Inspect for continuity
(Climate control unit—
ground: 2L—GND) Terminal Signal Connected to Test condition Voltage (V) Action