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Full-auto Air Conditioner

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
  1. Connect 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.
Fig 1: Identifying Climate Control Unit Connector Terminals
G03645068Courtesy of MAZDA MOTORS CORP.
CLIMATE CONTROL UNIT TERMINAL VOLTAGE LIST (REFERENCE)

Terminal Signal Connected to Test condition Voltage(V) Action
1A Air mix 1 Air mix actuator Moving to HOT See figure 2 in Fig 2
  • Inspect for continuity or short circuit (Climate control unit-air mix actuator: 1A - F)
  • Inspect air mix actuator
Moving to COLD
1B Air mix 2 Air mix actuator Moving to HOT See figure 2 in Fig 2
  • Inspect for continuity or short circuit (Climate control unit - air mix actuator: 1B - A)
  • Inspect air mix actuator
Moving to COLD
1C PWM output PWM unit Fan speed: 1-7 See figure 1 in Fig 2
  • Inspect for continuity or short circuit (Climate control unit-PWM unit: 1C-2A)
  • Inspect PWM unit
1D Air mix 3 Air mix actuator Moving to HOT See figure 2 in Fig 2
  • Inspect for continuity or short circuit (Climate control unit-air mix actuator: 1D - D)
  • Inspect air mix actuator
Moving to COLD
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 (2H, 2L)
  • Inspect center panel
1F On-board diagnostic signal DLC Terminal A of DLC is shorted. Below 1.0
  • Inspect for continuity (Climate control unit-DLC: 1F-A)
Other 5
  • Inspect short circuit (Climate control unit-DLC: 1F-A
  • Inspect terminal voltage of climate control unit (2H, 2L)
1G - - - - -
1H - - - - -
1I GND
  • Passenger compartment temperature sensor
  • Evaporator temperature sensor
  • Ambient temperature sensor
  • Water temperature sensor
  • Solar radiation sensor
  • Airflow mode actuator
 Under any condition Below 1.0
  • Inspect terminal voltage of climate control unit (2L)
1J Air mix 4 Air mix actuator Moving to HOT See figure 2 in Fig 2
  • Inspect for continuity or short circuit (Climate control unit-air mix actuator: 1J - C)
  • Inspect air mix actuator
Moving to COLD
1K Ambient temperature sensor input Ambient temperature sensor Depends on temperature surrounding sensor See figure 4 in Fig 3
  • Inspect for continuity (Climate control unit - ambient temperature sensor : 1K - B, 11 - 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 Passenger compartment temperature sensor input Passenger compartment temperature sensor Depends on temperature surrounding sensor See figure 5 in Fig 3
  • Inspect for continuity (Climate control unit-passenger compartment temperature sensor: 1M-B, 1I-A)
  • Inspect for short circuit (Climate control unit-passenger compartment temperature sensor: 1M-B)
  • Inspect passenger compartment temperature sensor
  • Inspect terminal voltage of climate control unit (2H, 2L)
1N - - - - -
1O Water temperature sensor input Water temperature sensor Depends on temperature surrounding sensor See figure 6 in Fig 3
  • 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-C) (Refrigerant pressure switch-PCM: B-1AC (L3-V), 41 (AJ-V))
  • Inspect refrigerant pressure switch
  • Inspect PCM terminal voltage (1AC (L3-V), 41 (AJ-V)) (See PCM INSPECTION [L3] ) (See PCM INSPECTION [AJ] )
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 3 in Fig 3
  • 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}  4.5
  • Inspect for continuity or short circuit (Climate control unit-solar radiation sensor: 1S-B, 2C-A)
  • Inspect terminal voltage of climate control unit (2C)
  • 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 Airflow mode actuator VENT mode 4.1
  • 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 (2C)
BI-LEVEL mode 3.3
HEAT mode 2.3
HEAT/DEF mode 1.5
DEFROSTER mode 0.9
1V - - - - -
1W - - - - -
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 +5 V
  • Airflow mode actuator
 Ignition switch at ON position 5
  • Inspect for short circuit (Climate control unit-airflow mode actuator: 2C-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 position Below 1.0
  • Replace climate control unit
2D - - - - -
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
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)
Fig 2: Voltage Signal Chart
G03645069Courtesy of MAZDA MOTORS CORP.
Fig 3: Voltage To Temperature Graphs
G03645070Courtesy of MAZDA MOTORS CORP.
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