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Symptom Troubleshooting (HVAC): Other Mazda 3 BL

FOREWORD

  1. The areas for inspection (steps) are given according to various circuit malfunctions. Use the following chart to verify the symptoms of the trouble in order to diagnose the appropriate area.

NO.1 INSUFFICIENT AIR (OR NO AIR) BLOWN FROM VENTS

1Insufficient air (or no air) blown from vents
DESCRIPTIONProblem with each vent or duct or both. Airflow mode dose not change.
POSSIBLE CAUSEMalfunction in airflow mode actuator Malfunction in VENT mode system Malfunction in HEAT mode system Malfunction in DEFROSTER mode system

DESCRIPTION AND POSSIBLE CAUSE

Full-auto Air Conditioner

2Amount of air blown from vents does not change.
DESCRIPTIONMalfunction in blower system
POSSIBLE CAUSEA/C unit malfunction Blower motor malfunction Malfunction in power MOS FET system Climate control unit malfunction

DESCRIPTION AND POSSIBLE CAUSE

  1. When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, inspect make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

Manual Air Conditioner

3Amount of air blown from vents does not change.
DESCRIPTIONMalfunction in blower system
POSSIBLE CAUSEBlower relay, blower motor, resistor, fan switch malfunction A/C unit malfunction

DESCRIPTION AND POSSIBLE CAUSE

NO.4 AIR INTAKE MODE DOES NOT CHANGE

4Air intake mode does not change.
DESCRIPTIONAir intake mode does not change when switching REC/FRESH mode.
POSSIBLE CAUSEAir intake actuator malfunction Air intake door malfunction

DESCRIPTION AND POSSIBLE CAUSE

  1. When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, inspect to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

NO.5 TEMPERATURE CONTROL WITH CLIMATE CONTROL UNIT

5No temperature control with climate control unit
DESCRIPTIONMalfunction in A/C unit and/or climate control unit air mix system
POSSIBLE CAUSEA/C unit air mix link, air mix crank, air mix rod, air mix wire, wire clamp malfunction Climate control unit rack-and-pinion, air mix wire malfunction A/C unit air mix door malfunction Heater piping malfunction

DESCRIPTION AND POSSIBLE CAUSE

NO.6 WINDSHIELD FOGGED

6Windshield fogged.
DESCRIPTIONA/C compressor does not operate while airflow mode is in DEFROSTER or HEAT/DEF modes. Air intake mode does not change to FRESH while airflow mode is in DEFROSTER or HEAT/DEF modes.
POSSIBLE CAUSEClimate control unit (B+ signal) system malfunction Air intake actuator malfunction Climate control unit (RECIRCULATE, FRESH signal) system malfunction A/C unit air intake door malfunction

DESCRIPTION AND POSSIBLE CAUSE

  1. When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while doing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, inspect to make sure connectors, terminals and wiring harness are connected correctly and undamaged.

NO.7 AIR FROM VENTS NOT COLD ENOUGH

7Air from vents not cold enough.
DESCRIPTIONMagnetic clutch operates but A/C system malfunctions.
POSSIBLE CAUSEDrive belt malfunction A/C unit or condenser malfunction Receiver/drier or expansion valve malfunction (valve closes too much) Malfunction in refrigerant lines A/C compressor system malfunction, insufficient compressor oil Over filling of compressor oil, malfunction in expansion valve or A/C unit air mix link system

DESCRIPTION AND POSSIBLE CAUSE

NO.8 NO COOL AIR

8No cool air
DESCRIPTIONMagnetic clutch does not operate.
POSSIBLE CAUSEMalfunction in PCM A/C cut control system Malfunction in climate control unit Malfunction in refrigerant pressure switch Malfunction in magnetic clutch Malfunction in PCM (IG1 signal) Malfunction in A/C compressor Malfunction in A/C relay Malfunction in evaporator temperature sensor

DESCRIPTION AND POSSIBLE CAUSE