Symptom Chart - Climate Control Systems

WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

CLIMATE CONTROL SYSTEMS SYMPTOM DESCRIPTION

Condition	Possible Sources	Action
NOTE: Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to the PCM DTC CHART .
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 .
HVAC functions are inoperative/do not operate correctly from touchscreen only	Communication network Front Control/Display Interface Module (FCDIM)	REFER to INFORMATION AND ENTERTAINMENT SYSTEMS and DIAGNOSE the touchscreen.
HVAC functions are inoperative/do not operate correctly from steering wheel switches/infotainment display only	Steering wheel switches Clockspring Steering Column Control Module (SCCM) Instrument Panel Cluster (IPC)	REFER to INFORMATION AND ENTERTAINMENT SYSTEMS and DIAGNOSE the steering wheel switches.
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 R .
The air inlet door is inoperative	Wiring, terminals or connectors Air inlet mode door actuator Air inlet mode door binding or stuck HVAC module Front Controls Interface Module (FCIM)	GO to PINPOINT TEST I .
Incorrect/erratic direction of airflow from outlets	Wiring, terminals or connectors Defrost/panel/floor mode door actuator Defrost/panel/floor mode door 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)	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 FCIM A/C clutch relay A/C compressor clutch air gap A/C pressure transducer Evaporator discharge air 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 discharge air 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 FCIM	GO to PINPOINT TEST N .
Temperature control is inoperative/does not operate correctly (Electronic Manual Temperature Control (EMTC))	Wiring, terminals or connectors HVAC module Temperature blend door is binding or stuck Temperature blend door actuator FCIM	GO to PINPOINT TEST O .
Temperature control is inoperative/does not operate correctly - LH	Wiring, terminals or connectors HVAC module Temperature blend door is binding or stuck Temperature blend door actuator FCIM	GO to PINPOINT TEST O .
Temperature control is inoperative/does not operate correctly - RH	Wiring, terminals or connectors HVAC module Temperature blend door is binding or stuck Temperature blend door actuator FCIM	GO to PINPOINT TEST P .
The blower motor is inoperative	Fuse(s) Wiring, terminals or connectors Blower motor relay Blower motor HVAC module Blower motor speed control FCIM	GO to PINPOINT TEST Q .
The blower motor does not operate correctly	Wiring, terminals or connectors Blower motor speed control HVAC module FCIM	GO to PINPOINT TEST R .
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.