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Home >> Ford >> 2012 >> Mustang Base, 2D Coupe, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 127 (HVAC - Climate Control System - General Information And Diagnostics - F150) >> Diagnosis And Testing >> Climate Control System >> Symptom Chart - Climate Control Systems

Symptom Chart - Climate Control Systems

WARNING: This page is about a different car, the 2012 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to the PCM DTC Chart .
SYMPTOM CHART - CLIMATE CONTROL SYSTEMS

Condition Possible Sources Action
  • No communication with the HVAC module
  • HVAC module
  • Communication network
  • Unable to duplicate the customer concern and no DTCs present
  • HVAC system and/or related components
  • Reduced outlet airflow
  • Wiring, terminals or connectors
  • A/C compressor clutch air gap
  • A/C evaporator temperature sensor
  • A/C clutch relay
  • Blower motor control
  • For Electronic Manual Temperature Control (EMTC), if the A/C compressor cycles normally, GO to PINPOINT TEST X .
  • Blower motor resistor
  • PCM
  • HVAC module
  • Front Controls Interface Module (FCIM)
  • For Dual Automatic Temperature Control (DATC), if the A/C compressor cycles normally, GO to PINPOINT TEST Z .
  • The air inlet door is inoperative
  • Wiring, terminals or connectors
  • Air inlet mode door actuator
  • Stuck or bound linkage or door
  • HVAC module
  • FCIM
  • Incorrect/erratic direction of airflow from outlets
  • Wiring, terminals or connectors
  • Defrost/panel/floor mode door actuator
  • Stuck or bound linkage or door
  • HVAC module
  • FCIM
  • Insufficient, erratic or no heat
  • Low engine coolant level
  • Plugged or partially plugged heater core
  • Temperature blend door(s) binding or stuck
  • Temperature blend door actuator(s)
  • The air conditioning (A/C) is inoperative
  • Fuse(s)
  • Wiring, terminals or connectors
  • A/C system discharged/low charge
  • PCM
  • HVAC module
  • FCIM
  • A/C clutch relay
  • A/C compressor clutch air gap
  • A/C pressure transducer
  • Evaporator temperature sensor
  • A/C compressor clutch field coil
  • The air conditioning (A/C) is always on - A/C compressor does not cycle
  • Wiring, terminals or connectors
  • PCM
  • Evaporator temperature sensor
  • A/C clutch relay
  • A/C compressor clutch air gap
  • The air conditioning (A/C) is always on - A/C mode always commanded ON
  • Wiring, terminals or connectors
  • PCM
  • FCIM
  • HVAC module
  • Temperature control is inoperative/does not operate correctly - EMTC
  • Wiring, terminals or connectors
  • HVAC module
  • Stuck or bound linkage or door
  • Temperature blend door actuator
  • Temperature control is inoperative/does not operate correctly - DATC, LH
  • Wiring, terminals or connectors
  • HVAC module
  • Stuck or bound linkage or door
  • Temperature blend door actuator
  • FCIM
  • Temperature control is inoperative/does not operate correctly - DATC, RH
  • Wiring, terminals or connectors
  • HVAC module
  • Stuck or bound linkage or door
  • Temperature blend door actuator
  • FCIM
  • The blower motor is inoperative - EMTC
  • Fuse(s)
  • Wiring, terminals or connectors
  • Blower motor relay
  • Blower motor
  • HVAC module
  • The blower motor does not operate correctly - EMTC
  • Wiring, terminals or connectors
  • Blower motor resistor
  • HVAC module
  • The blower motor is inoperative - DATC
  • Fuse(s)
  • Wiring, terminals or connectors
  • Blower motor relay
  • Blower motor
  • HVAC module
  • Blower motor speed control
  • The blower motor does not operate correctly - DATC
  • Wiring, terminals or connectors
  • Blower motor speed control
  • HVAC module
  • FCIM
  • A/C pressure relief valve discharging
  • High system pressure
  • A/C pressure relief valve
  • CHECK the high side system pressure. If the pressure is below the A/C pressure relief valve open pressure, REPLACE the A/C pressure relief valve. If the system pressure is above the A/C pressure relief valve open pressure, REPAIR the system for a restriction.