Climate Control System Symptom Troubleshooting Index

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

Symptom	Diagnostic Procedure	Also Check for
The blower, the heater controls, and the A/C system do not work	Symptom Troubleshooting	Blown fuse No. D9 Poor ground at G251 Climate control unit Harness/connections
The electric A/C compressor 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 Evaporator temperature sensor Harness/connections
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 engine coolant temperature rises when in AUTO mode	Probable cause: Engine coolant temperature (ECT) circuit malfunction Troubleshoot the ECT sensor circuit: ECT sensor 1 out of range ECT sensor 1 circuit range/performance problem ECT sensor 1 circuit low voltage ECT sensor 1 circuit high voltage	Climate control DTCs PGM-FI DTCs Manual blower motor operation
Driver's and passenger's side vent temperatures vary by more than 20 deg.F (11 deg.C)	Probable cause: The air mix doors are malfunctioning Do the following troubleshooting: - Air mix control motor test1 - Driver's air mix control motor test2 - Passenger's air mix control motor test*2 Low refrigerant charge	Climate control DTCs Harness/connections
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, the heater, and the A/C system controls work (climate control panel without display)	Probable cause: Communication malfunction between the audio unit and the climate control unit Check the B-CAN line between the audio unit and the climate control unit	Climate control DTCs
When an engine stops, the heater does not warm (The PTC heater does not heat up)	Do the PTC heater circuit troubleshooting	Blown fuse No. C1-1 Blown fuse No. C1-3 Poor ground at G352 PTC heater B relay PTC heater D relay PTC heater core Climate control unit Harness/connections
Insufficient heating	Check the engine coolant level Check the radiator cap 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 test1 Driver's air mix control motor test2 Passenger's air mix control motor test*2 Check the blower motor unit for obstructions Check for air leaks around the ducts and vents	Climate control DTCs

*1: Without dual zone climate control

*2: With dual zone climate control