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Climate Control Unit Inspection (Auto A/C): Notes

G12188183Courtesy of MAZDA MOTORS CORP.
  1. Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
  2. Remove the following parts:
    1. Console side panel (See CONSOLE SIDE PANEL REMOVAL/INSTALLATION .)
    2. Switch panel (See SWITCH PANEL REMOVAL/INSTALLATION .)
    3. Cup holder (See CUP HOLDER REMOVAL/INSTALLATION .)
    4. Selector lever knob (ATX) (See SELECTOR LEVER COMPONENT REMOVAL/INSTALLATION .)
    5. Shift panel (See SHIFT PANEL REMOVAL/INSTALLATION .)
    6. Front console box (See FRONT CONSOLE BOX REMOVAL/INSTALLATION .)
    7. Side wall (See SIDE WALL REMOVAL/INSTALLATION .)
    8. Rear console (See REAR CONSOLE REMOVAL/INSTALLATION .)
    9. Driver-side front scuff plate (See FRONT SCUFF PLATE REMOVAL/INSTALLATION .)
    10. Driver-side front side trim (See FRONT SIDE TRIM REMOVAL/INSTALLATION .)
    11. Lower decoration panel (See DECORATION PANEL REMOVAL/INSTALLATION .)
    12. Hood release lever (See HOOD RELEASE LEVER AND RELEASE CABLE REMOVAL/INSTALLATION .)
    13. Fuel filer lid opener lever (See FUEL-FILLER LID OPENER AND LEVER REMOVAL/INSTALLATION .)
    14. Driver-side lower panel (See LOWER PANEL REMOVAL/INSTALLATION .)
    15. Center lower panel (See CENTER LOWER PANEL REMOVAL/INSTALLATION .)
  3. Remove the climate control unit with the connector connected. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION (AUTO A/C) .)
  4. Connect the negative battery terminal.
  5. Switch the ignition ON (engine off or on).
  6. Connect the negative (-) lead of the tester to body ground.
  7. Insert the positive (+) lead of the tester into each climate control unit terminal and measure the voltage according to the terminal voltage table.

    Terminal Voltage Table (Reference) 

    G11431879Courtesy of MAZDA MOTORS CORP.
TERMINAL VOLTAGE DESCRIPTION

Terminal Signal name Connected to Measurement condition Voltage (V) Inspection item(s)
1A Passenger compartment temperature sensor input Passenger compartment temperature sensor Compared with temperature detected by passenger compartment temperature sensor Refer to graph 1
  • Related wiring harness
  • Passenger compartment temperature sensor
  • Climate control unit: terminal voltage (1Q)
1B Potentiometer input Airflow mode actuator VENT 4. 3
  • Related wiring harness
  • Airflow mode actuator
  • Climate control unit: terminal voltage (1C, 1Q)
BI-LEVEL 3. 4
HEAT 2. 5
HEAT/DEF 1. 6
DEFROSTER 0. 7
1C +5V
  • Air intake actuator
  • Driver-side air mix actuator
  • Passenger-side air mix actuator
  • Airflow mode actuator
  • Solar radiation sensor
Under any condition 5. 0
  • Related wiring harness
  • Air intake actuator
  • Driver-side air mix actuator
  • Passenger-side air mix actuator
  • Airflow mode actuator
  • Solar radiation sensor
  • Climate control unit: terminal voltage (1Q)
1D Potentiometer input Air intake actuator RECIRCULATE 1. 0
  • Related wiring harness
  • Air intake actuator
  • Climate control unit: terminal voltage (1C, 1Q)
FRESH 3. 9
1E Evaporator temperature sensor input Evaporator temperature sensor Compared with temperature detected by evaporator temperature sensor Refer to graph 2
  • Related wiring harness
  • Evaporator temperature sensor
  • Climate control unit: terminal voltage (1Q)
1F Solar radiation sensor (RH) input Solar radiation sensor Sunlight shined directly on solar radiation sensor 4
  • Related wiring harness
  • Climate control unit: terminal voltage (1C)
  • Solar radiation sensor
Blocking light to solar radiation sensor 1. 0 or less
1G - - - - -
1H Solar radiation sensor (LH) input Solar radiation sensor Sunlight shined directly on solar radiation sensor 4
  • Related wiring harness
  • Climate control unit: terminal voltage (1C)
  • Solar radiation sensor
Blocking light to solar radiation sensor 1. 0 or less
1I GND Body ground Under any condition 1. 0 or less
  • Related wiring harness
1J Motor operation (HOT) Driver-side air mix actuator Moving towards HOT B+
  • Related wiring harness
  • Driver-side air mix actuator
Moving towards COLD 1. 0 or less
1K MS_CAN_H CAN related module Because this terminal is for communication, integrity determination by terminal voltage is not possible.
L Motor operation (COLD) Driver-side air mix actuator Moving towards HOT 1. 0 or less
  • Related wiring harness
  • Driver-side air mix actuator
Moving towards COLD B+
1M MS_CAN_L CAN related module Because this terminal is for communication, integrity determination by terminal voltage is not possible.
1N IG2 Front body control module (FBCM) Switch the ignition ON (engine off or on) B+
  • Related wiring harness
  • Front body control module (FBCM)
Switch the ignition off 1. 0 or less
1O - - - - -
1P - - - - -
1Q Sensor GND
  • Air intake actuator
  • Driver-side air mix actuator
  • Passenger-side air mix actuator
  • Airflow mode actuator
  • Evaporator temperature sensor
  • Passenger compartment temperature sensor
Under any condition 1. 0 or less
  • Related wiring harness
1R - - - - -
1S - - - - -
1T Blower fan speed control Blower fan controller (See BLOWER FAN SPEED CONTROL SIGNAL )
  • Related wiring harness
  • Blower fan controller
1U B+ ROOM 15 A fuse Under any condition B+
  • Related wiring harness
  • ROOM 15 A fuse
1V - - - - -
1W IG1 C/U IG1 15 A fuse Switch the ignition ON (engine off or on) B+
  • Related wiring harness
  • C/U IG1 15 A fuse
Switch the ignition off 1. 0 or less
1X(1) Front seat warmer switch signal Front seat warmer control unit Because this terminal is for communication, determination using terminal voltage inspection is not possible
Seat ventilation switch signal
2A Motor operation (HOT) Passenger-side air mix actuator Moving towards HOT B+
  • Related wiring harness
  • Passenger-side air mix actuator
Moving towards COLD 1. 0 or less
2B Motor operation (DEFROSTER) Airflow mode actuator Moving towards DEFROSTER B+
  • Related wiring harness
  • Airflow mode actuator
Moving towards VENT 1. 0 or less
2C Motor operation (COLD) Passenger-side air mix actuator Moving towards HOT 1. 0 or less
  • Related wiring harness
  • Passenger-side air mix actuator
Moving towards COLD B+
2D Motor operation (VENT) Airflow mode actuator Moving towards VENT B+
  • Related wiring harness
  • Airflow mode actuator
Moving towards DEFROSTER 1. 0 or less
2E - - - - -
2F Motor operation (RECIRCULATE) Air intake actuator Moving towards RECIRCULATE B+
  • Related wiring harness
  • Air intake actuator
Moving towards FRESH 1. 0 or less
2G - - - - -
2H Motor operation (FRESH) Air intake actuator Moving towards RECIRCULATE 1. 0 or less
  • Related wiring harness
  • Air intake actuator
Moving towards FRESH B+
2I Potentiometer input Passenger-side air mix actuator Set temperature at MAX HOT 4. 3
  • Related wiring harness
  • Passenger-side air mix actuator
  • Climate control unit: terminal voltage (1C, 1Q)
Set temperature at MAX COLD 0. 7
2J - - - - -
2K Potentiometer input Driver-side air mix actuator Set temperature at MAX HOT 4. 3
  • Related wiring harness
  • Driver-side air mix actuator
  • Climate control unit: terminal voltage (1C, 1Q)
Set temperature at MAX COLD 0. 7
2L - - - - -
(1) Climate control unit type B with front seat warmer system or seat ventilation system
G13113527Courtesy of MAZDA MOTORS CORP.
G13113528Courtesy of MAZDA MOTORS CORP.