Mazda 6. Manual — part 386

U–48

CONTROL SYSTEM

1C

Blower motor
control signal

Power MOS FET

Fan switch is OFF

Below 1.0

• Inspect terminal voltage of

climate control unit (1A)

Fan switch is at manual
LO

4.1

Fan switch is at manual
HI

7.9

1D

—

—

—

—

—

1E

Rear window
defroster SW
signal

Rear window
defroster relay

Rear 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 (1H, 1L)

• Inspect audio switch panel

1F

On-board
diagnostic signal

A/C check
connector

Terminal 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

actuator

Under any condition

Below 1.0

• Inspect terminal voltage of

climate control unit (2L)

1J

—

—

—

—

—

1K

Ambient
temperature
sensor input

Ambient
temperature sensor

Depends 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

—

—

—

—

—

1M

Cabin
temperature
sensor input

Cabin temperature
sensor

Depends 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

—

—

—

—

—

Terminal

Signal

Connected to

Test condition

Voltage (V)

Action

CONTROL SYSTEM

U–49

U

1O

Water
temperature
sensor input

Water temperature
sensor

Depends 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 switch

Fan switch at OFF

12

• Inspect for continuity or

short circuit (Climate control
unit—refrigerant pressure
switch: 1P—A (Dual-
pressure type), 1P—C
(Triple-pressure type))
(Refrigerant pressure
switch—PCM: B—1AC)

• Inspect refrigerant pressure

switch

• Inspect PCM terminal

voltage (1AC)
(See

F–45 PCM

INSPECTION

)

Fan switch at 1st
position, A/C switch ON

Below 1.0

• Inspect terminal voltage of

climate control unit (2H, 2L)

1Q

Evaporator
temperature
sensor input
signal

Evaporator
temperature sensor

Depends on temperature
surrounding sensor

See Figure

1

• Inspect for continuity

(Climate control unit—
evaporator temperature
sensor: 1Q—A, 1I—B)

• Inspect for short circuit

(Climate control unit—
evaporator temperature
sensor: 1Q—A)

• Inspect evaporator

temperature sensor

• Inspect terminal voltage of

climate control unit (2H, 2L)

1R

—

—

—

—

—

1S

Solar radiation
sensor input

Solar radiation
sensor

Incandescent 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 block

Below 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
signal

Air mix actuator

Set temperature at MAX
COLD

0.6

• 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

—

—

—

—

—

Terminal

Signal

Connected to

Test condition

Voltage (V)

Action

U–50

CONTROL SYSTEM

1W

Potentiometer
signal

Airflow mode
actuator

VENT 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 signal

Hazard warning
switch

Hazard 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
signal

Panel light control
switch

Headlight 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. illumination

10.2

• Inspect for short circuit

(Climate control unit— panel
light control switch: 2A—C)

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
actuator

Moving 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
actuator

Moving 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

Terminal

Signal

Connected to

Test condition

Voltage (V)

Action

CONTROL SYSTEM

U–51

U

End Of Sie

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
RECIRCULATE

12

• 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