Symptom Chart - Climate Control Systems

WARNING: This page is about a different variant/trim than selected.

SYMPTOM CHART - CLIMATE CONTROL SYSTEMS

Condition	Possible Sources	Action
Unable to duplicate the customer concern and no DTCs present	Incorrect functioning of the HVAC system and/or related components	GO to PINPOINT TEST B .
Reduced outlet airflow	Wiring, terminals or connectors PCM Function selector switch A/C clutch relay A/C compressor clutch air gap Blower motor resistor Blower motor switch	If the A/C compressor does not cycle, GO to PINPOINT TEST F . If the A/C compressor cycles normally, GO to PINPOINT TEST K .
Incorrect/erratic direction of airflow from outlets	Function selector switch Vacuum hose/harness Vacuum control motor A/C vacuum check valve Vacuum reservoir tank Air distribution door/linkage	GO to PINPOINT TEST C .
Insufficient, erratic or no heat	Low engine coolant level Engine overheating Plugged or partially plugged heater core Temperature blend door binding/stuck Temperature blend door actuator	GO to PINPOINT TEST D .
The air conditioning (A/C) is inoperative	Fuse(s) Wiring, terminals or connectors A/C cycling switch Low refrigerant system charge Function selector switch A/C high pressure switch A/C clutch relay PCM A/C compressor clutch air gap A/C compressor clutch field coil	GO to PINPOINT TEST E .
The air conditioning (A/C) is always on - A/C compressor does not cycle	Wiring, terminals or connectors Function selector switch A/C clutch relay PCM A/C compressor clutch air gap	GO to PINPOINT TEST F .
The air conditioning (A/C) is always on - A/C mode always commanded ON	Wiring, terminals or connectors Function selector switch A/C clutch relay PCM A/C compressor clutch air gap	GO to PINPOINT TEST G .
Insufficient air conditioning (A/C) cooling - auxiliary system	Thermostatic Expansion Valve (TXV) Leaking or restricted vacuum hose Vacuum control motor Stuck or bound linkage or door	GO to PINPOINT TEST H .
Temperature control is inoperative/does not operate correctly	Fuse(s) Wiring, terminals or connectors Temperature blend door actuator Temperature control potentiometer Stuck or bound linkage or door	GO to PINPOINT TEST I .
The blower motor is inoperative	Fuse(s) Wiring, terminals or connectors Blower motor relay Function selector switch Blower motor	GO to PINPOINT TEST J .
The blower motor does not operate correctly	Wiring, terminals or connectors Blower motor resistor Blower motor switch	GO to PINPOINT TEST K .
The auxiliary blower motor is inoperative	Fuse(s) Wiring, terminals or connectors Auxiliary blower motor relay Auxiliary blower motor switch Auxiliary high speed blower motor relay Auxiliary blower motor Auxiliary blower motor resistor Function selector switch	GO to PINPOINT TEST L .
The auxiliary blower motor does not operate correctly	Wiring, terminals or connectors Auxiliary blower motor resistor Auxiliary blower motor switch Auxiliary blower motor relay Auxiliary high speed blower motor relay	GO to PINPOINT TEST M .
The auxiliary temperature/mode is inoperative/does not operate correctly	Auxiliary temperature actuator Auxiliary mode actuator Auxiliary vacuum source line	If both temperature and mode are affected, REPAIR the vacuum source line for an obstruction or leak. TEST the system for normal operation. If the temperature or mode alone are affected, INSPECT the temperature or mode door for a binding or broken condition. If no condition is found, INSTALL a new actuator. 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, INSTALL a new 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.