Climate Control System Symptom Troubleshooting Index (2017 2018 2019)

Symptom	Diagnostic Procedure	Also Check for
The blower and the heater controls and the A/C system do not work	Symptom Troubleshooting	Climate control DTCs Blown fuse No. D9 (10 A) in the under-dash fuse/relay box Poor ground at G402 Poor or loose connections at the terminals
The A/C compressor clutch and the cooling fan are inoperative, but the blower and heater controls work	Probable cause: A/C pressure sensor circuit malfunction or evaporator temperature sensor circuit malfunction Troubleshoot the A/C pressure sensor circuit: A/C pressure sensor circuit low voltage A/C pressure sensor circuit high voltage NOTE: The A/C pressure sensor circuit can malfunction without setting a DTC	Climate control DTCs PGM-FI DTCs Abnormal A/C system pressures Faulty evaporator temperature sensor Poor or loose connections at the terminals
The A/C compressor clutch does not engage, but the cooling fan operate, and the blower and heater controls work	Symptom Troubleshooting	Climate control DTCs Blown fuse No. A23 (10 A) in the under-hood fuse/relay box Abnormal A/C system pressures Poor or loose connections at the terminals
Blower fan runs slower than expected in cold weather (when in AUTO mode) NOTE: It is normal for the blower fan to run slowly until the coolant temperature rises when in AUTO mode	Probable cause: Engine coolant temperature (ECT) circuit malfunction Troubleshoot the ECT sensor circuit: ECT sensor 2 circuit low voltage ECT sensor 2 circuit high voltage	Climate control DTCs PGM-FI DTCs Blower motor operation
The A/C compressor clutch cycles rapidly on and off *6	Probable cause: A/C system is overcharged (Excessive pressure on high side of system causing pressure sensor to turn A/C compressor off) Cooling fan inoperative Low idle speed Evaporator temperature sensor malfunction Do the evaporator temperature sensor test	Climate control DTCs If there is no leak and the refrigerant level is normal, do the A/C compressor clutch circuit troubleshooting , and look for an intermittent problem Faulty A/C pressure sensor
The A/C compressor clutch does not disengage when the A/C switch is off	Probable cause: The A/C compressor clutch circuit is on (energized) continuously, shorted to ground, stuck A/C compressor clutch relay, or the A/C compressor clutch is mechanically jammed Do the A/C compressor clutch check , and repair any problems with the A/C compressor clutch	The A/C compressor relief valve. If it has vented refrigerant to the atmosphere, correct the problem with the A/C compressor clutch or the A/C compressor clutch circuit, then replace the A/C compressor relief valve

*1: Without navigation *2: With navigation*3: Without dual zone control*4: With dual zone control*5: 1.5 L engine*6: 2.4 L engine

Symptom	Diagnostic Procedure	Also Check for
The A/C compressor relief valve has vented refrigerant NOTE: This indicates the A/C system high side pressure was high	Probable cause: A high-side restriction, the cooling fan is inoperative, or the A/C compressor clutch is not disengaging If the fans and A/C compressor clutch operate normally, feel the lines for restrictions Do the A/C system contamination inspection If the A/C compressor clutch will not disengage, troubleshoot the A/C compressor clutch circuit , and check for mechanical problems If the A/C condenser/radiator fans are inoperative, troubleshoot the fan circuits	PGM-FI DTCs
Driver's and passenger's side vent temperatures vary by more than 11°C (20°F)	Probable cause: The air mix doors are malfunctioning Do the following troubleshooting: - Air mix control motor test3 - Driver's air mix control motor test 4 - Passenger's air mix control motor test*4 Low refrigerant charge Variable capacity control solenoid malfunction	Climate control DTCs Poor or loose connections at the terminals
HDS does not communicate with the climate control unit or the vehicle	Troubleshoot the DLC circuit
A/C information does not display on the center display unit, but the blower, heater and A/C system controls work (climate control panel without display)	Probable cause: Communication malfunction between the audio unit 1 or the audio-navigation unit 2 and the climate control unit Check the B-CAN line between the audio unit 1 or the audio-navigation unit 2 and the climate control unit	Climate control DTCs
Insufficient heating	Check the coolant level Check the expansion tank cap5 or the radiator cap6 Check the engine coolant temperature (ECT) during normal operation with the HDS Check the heater core inlet hose temperature: If it is COLD, check for restrictions in the hose, a damaged or leaking thermostat, or a damaged or leaking water pump If it is HOT, check for restrictions in the heater core. Back flush or replace the heater core Check the operation of the air mix doors: Air mix control motor test3 Driver's air mix control motor test 4 Passenger's air mix control motor test*4 Check the blower motor unit for obstructions Check for air leaks around the ducts and vents	Climate control DTCs

*1: Without navigation *2: With navigation*3: Without dual zone control*4: With dual zone control*5: 1.5 L engine*6: 2.4 L engine