Symptom Troubleshooting Index

SYMPTOM TROUBLESHOOTING INDEX

Symptom	Diagnostic Procedure	Also Check for
The blower and heater controls and the A/C system do not work	Probable cause: Climate control unit malfunction. Do the climate control power and ground circuit troubleshooting (see CLIMATE CONTROL POWER AND GROUND CIRCUIT TROUBLESHOOTING )	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Blown fuse No. 16 (7.5 A) in the driver's under-dash fuse/relay box Poor ground at G401; with navigation (see AUDIO WIRE HARNESS (WITH NAVIGATION) ), without navigation (see AUDIO WIRE HARNESS (WITHOUT NAVIGATION) ) Poor or loose connections at the terminals
The A/C compressor clutch and the A/C condenser/radiator fans are inoperative, but the blower and heater controls work	Probable cause: A/C pressure sensor circuit malfunction. Do the pressure sensor troubleshooting: A/C pressure sensor circuit low voltage (see DTC P0532: A/C PRESSURE SENSOR CIRCUIT LOW VOLTAGE ), A/C pressure sensor circuit high voltage (see DTC P0533: A/C PRESSURE SENSOR CIRCUIT HIGH VOLTAGE ) NOTE: The A/C pressure sensor can malfunction without setting a DTC	B-CAN U-codes, loss of communication Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Powertrain DTCs Poor or loose connections at the terminals
The A/C compressor clutch does not engage, but the A/C condenser / radiator fans operate, and the blower and heater controls work	Probable cause: No power to the A/C compressor clutch. Do the A/C compressor clutch circuit troubleshooting (see A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING )	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Blown fuse No. 20 (7.5 A) in the under-hood fuse/relay box A/C system pressure is normal (see A/C SYSTEM TEST ) Poor or loose connections at the terminals ECT Engine overheating
The A/C condenser/radiator fans do not run at low speed with the A/C on, but the blower and heater controls work normally	Probable cause: A/C condenser/radiator fan low speed circuit malfunction. Do the radiator and A/C condenser fan low speed circuit troubleshooting (see RADIATOR AND A/C CONDENSER FAN LOW SPEED CIRCUIT TROUBLESHOOTING ) Probable cause: A/C pressure sensor circuit malfunction. Do the A/C pressure sensor troubleshooting: A/C pressure sensor circuit low voltage (see DTC P0532: A/C PRESSURE SENSOR CIRCUIT LOW VOLTAGE ), A/C pressure sensor circuit high voltage (see DTC P0533: A/C PRESSURE SENSOR CIRCUIT HIGH VOLTAGE ) NOTE: The A/C pressure sensor can malfunction without setting a DTC	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Powertrain DTCs Blown fuse No. 3-6 (MAIN FAN MTR) (30 A) in the under-hood fuse/relay box Blown fuse No. 5 (20 A) in the under-hood fuse/relay box Poor ground at G301 (see LEFT ENGINE COMPARTMENT WIRE HARNESS (ENGINE COMPARTMENT BRANCH) ) Poor or loose connections at the terminals
The A/C condenser / radiator fans do not run at high speed, but do run at low speed	Probable cause: Malfunction in the fan(s) high speed circuit. Do the following troubleshooting as needed: A/C condenser fan high speed circuit troubleshooting (see A/C CONDENSER FAN HIGH SPEED CIRCUIT TROUBLESHOOTING ) Radiator fan high speed circuit troubleshooting (see RADIATOR FAN HIGH SPEED CIRCUIT TROUBLESHOOTING ) Probable cause: A/C pressure sensor circuit malfunction. Do the A/C pressure sensor troubleshooting: A/C pressure sensor circuit low voltage (see DTC P0532: A/C PRESSURE SENSOR CIRCUIT LOW VOLTAGE ), A/C pressure sensor circuit high voltage (see DTC P0533: A/C PRESSURE SENSOR CIRCUIT HIGH VOLTAGE ) NOTE: The A/C pressure sensor can malfunction without setting a DTC	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Powertrain DTCs Blown fuse No. 5 (20 A) in the under-hood fuse/relay box Poor ground at G301 (see LEFT ENGINE COMPARTMENT WIRE HARNESS (ENGINE COMPARTMENT BRANCH) ) Poor or loose connections at the terminals
Voice commands do not work (with navigation)	Probable cause: Communication problem between the climate control unit and the navigation system. Do the navigation communication line circuit troubleshooting (see NAVIGATION COMMUNICATION LINE CIRCUIT TROUBLESHOOTING )	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Navigation System Links (see SYSTEM LINKS ) Poor or loose connections at the terminals
The climate control display is inoperative	Probable cause: Communication problem between the climate control unit and the audio-navigation switch panel (with navigation) or the audio-HVAC display unit (without navigation). Do the audio communication line circuit troubleshooting; with navigation (see WITH NAVIGATION ), without navigation (see WITHOUT NAVIGATION )	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Audio-navigation switch panel or audio-HVAC display unit failure Poor or loose connections at the terminals
Blower fan runs slower than expected in cold weather (when in AUTO mode)	Probable cause: Engine coolant temperature (ECT) circuit malfunction Troubleshoot the ECT sensor circuit: ECT sensor 2 circuit low voltage (see DTC P2184: ECT SENSOR 2 CIRCUIT LOW VOLTAGE ) ECT sensor 2 circuit high voltage (see DTC P2185: ECT SENSOR 2 CIRCUIT HIGH VOLTAGE )	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Powertrain DTCs Blower motor operation
The A/C compressor clutch cycles rapidly on and off	Probable cause: The A/C system is very low on refrigerant, indicating a possible leak. Do the refrigerant leak check (see REFRIGERANT LEAK CHECK ) and repair any leaks. Replace the receiver/dryer (see RECEIVER/DRYER DESICCANT REPLACEMENT ), then recharge the system to specifications (see SYSTEM CHARGING )	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) If there is no leak and the refrigerant level is normal, do the A/C compressor clutch circuit troubleshooting (see A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING ), and look for an intermittent problem
Driver's and passenger's side vent temperatures vary by more than 20°F (11°C)	Probable causes: The recirculation control door or the air mix doors are malfunctioning. Do the following troubleshooting: Recirculation control motor test (see RECIRCULATION CONTROL MOTOR TEST ) Driver's air mix control motor test (see DRIVER'S AIR MIX CONTROL MOTOR TEST ) Passenger's air mix control motor test (see PASSENGER'S AIR MIX CONTROL MOTOR TEST )	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Poor or loose connections at the terminals
HDS does not communicate with the climate control unit or the vehicle	Troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING )
Insufficient heating	Check the coolant level (see COOLANT CHECK ) Check the radiator cap (see RADIATOR CAP TEST ) Check the coolant temperature during normal operation 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 Do the driver's air mix control motor test (see DRIVER'S AIR MIX CONTROL MOTOR TEST ) and passenger's air mix control motor test (see PASSENGER'S AIR MIX CONTROL MOTOR TEST ) Check the blower motor unit for obstructions Check for air leaks around the ducts and vents	Climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ) Damaged cylinder head gasket