Symptom Chart - Climate Control Systems

WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. 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	Fuse(s) Wiring, terminals or connectors HVAC module communication network	REFER to MODULE COMMUNICATIONS NETWORK .
Unable to duplicate the customer concern and no DTCs present	HVAC system and/or related components	GO to PINPOINT TEST H .
Reduced outlet airflow	Wiring, terminals or connectors A/C compressor clutch air gap A/C pressure transducer Evaporator temperature sensor A/C clutch relay Blower motor Blower motor control PCM	If the A/C compressor does not cycle, GO to PINPOINT TEST M . If the A/C compressor cycles normally, GO to PINPOINT TEST Q .
The air inlet door is inoperative	Wiring, terminals or connectors Air inlet mode door actuator Air inlet mode door binding or stuck HVAC module	GO to PINPOINT TEST I .
Incorrect/erratic direction of airflow from outlets	Wiring, terminals or connectors Defrost/panel/floor mode door actuator Mode door(s) binding or stuck HVAC module	GO to PINPOINT TEST J .
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) Auxiliary Heater Control Module (AHCM)	GO to PINPOINT TEST K .
The air conditioning (A/C) is inoperative	Fuse(s) Wiring, terminals or connectors A/C system discharged/low charge PCM HVAC module A/C clutch relay A/C compressor clutch air gap A/C pressure transducer Evaporator temperature sensor A/C compressor clutch field coil	GO to PINPOINT TEST L .
The air conditioning (A/C) is always on - A/C compressor does not cycle	Wiring, terminals or connectors PCM A/C clutch relay A/C compressor clutch air gap Evaporator temperature sensor	GO to PINPOINT TEST M .
The air conditioning (A/C) is always on - A/C mode always commanded on	Wiring, terminals or connectors PCM HVAC module	GO to PINPOINT TEST N .
Temperature control is inoperative/does not operate correctly	Wiring, terminals or connectors HVAC module Temperature blend door is binding or stuck Temperature blend door actuator(s)	GO to PINPOINT TEST O .
The blower motor is inoperative	Fuse(s) Wiring, terminals or connectors Blower motor relay Blower motor HVAC module Blower motor speed control	GO to PINPOINT TEST P .
The blower motor does not operate correctly	Wiring, terminals or connectors Blower motor speed control HVAC module	GO to PINPOINT TEST Q .
The electric heater is inoperative/does not operate correctly	Fuse(s) Wiring, terminals or connectors Auxiliary Heater Control Module (AHCM)	GO to PINPOINT TEST S .
The temperature set point does not repeat after turning the ignition switch OFF	HVAC module	INSTALL a new HVAC module. REFER to CLIMATE CONTROL . TEST the system for normal operation.
The temperature display will not switch between Celsius and Fahrenheit	HVAC module Instrument Panel Cluster (IPC)	If the IPC does not switch between English and Metric, REFER to INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES and diagnose. If only the HVAC module does not switch between English and Metric, INSTALL a new HVAC module. REFER to CLIMATE CONTROL . TEST the system for normal operation.
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.