Symptom Chart - Climate Control Systems

NOTE: Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to Introduction - Gasoline Engines .

Condition	Possible Sources	Action
The air inlet door is inoperative	Circuitry short/open Electronic manual temperature control (EMTC) module Air inlet door actuator/linkage	Go to Pinpoint Test A .
Incorrect/erratic direction of airflow from outlets	Circuitry Door actuator Mode door binding or stuck HVAC module Door actuator arm not connected to the door crank	Go to Pinpoint Test B .
Insufficient, erratic or no heat	Low engine coolant level Engine overheating Plugged or partially plugged heater core Temperature blend door is binding or stuck Temperature blend door actuator Heater hose is kinked or binding	Go to Pinpoint Test C .
The air conditioning (A/C) is inoperative/does not operate correctly	Fuse Circuitry short/open A/C system discharged/low charge A/C dual function pressure switch PCM Smart junction box (SJB) HVAC module A/C cycling switch A/C compressor clutch air gap A/C clutch relay	Go to Pinpoint Test D .
The air conditioning (A/C) is always ON	Circuitry short PCM SJB A/C compressor clutch air gap A/C clutch relay	Go to Pinpoint Test E .
Temperature control is inoperative/does not operate correctly	Circuitry open/shorted HVAC module Temperature blend door Temperature blend door actuator	Go to Pinpoint Test B .
The blower motor is inoperative	Fuse(s) Circuitry open/shorted A/C blower motor switch Blower motor relay A/C blower motor	Go to Pinpoint Test F .
The blower motor does not operate correctly	Circuitry short A/C blower motor resistor A/C blower motor switch	Go to Pinpoint Test G .
Insufficient air conditioning (A/C) cooling	Low refrigerant level Temperature blend door actuator	Go to Pinpoint Test B .