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HOMESERVICE MANUALSACURA2008CSX BASE, K20A3REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 17 (CLIMATE CONTROL SYSTEM)CLIMATE CONTROLSYMPTOM TROUBLESHOOTING INDEX

2008 Acura CSX Base, K20A3

Symptom Troubleshooting Index

2008 Acura CSX Base, K20A3SECTION Symptom Troubleshooting Index

WARNING: This page is about a different car, the 2011 Acura TL, 2010 Acura TL, and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM TROUBLESHOOTING INDEX

Symptom	Diagnostic procedure	Also check for
The blower and heater controls and the A/C system do not work	Probable cause The climate control unit has malfunctioned, or has lost power or ground Do the climate control power and ground circuit troubleshooting (see CLIMATE CONTROL POWER AND GROUND CIRCUIT TROUBLESHOOTING )	Climate control DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Blown fuse No 16(7 5 A) in the driver's under-dash fuse/relay box Poor ground at G403 (see DASHBOARD WIRE HARNESS (VIEW OF MIDDLE TO PASSENGER'S SIDE) ) 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 Troubleshoot the A/C pressure sensor circuit NOTE: The A/C pressure sensor can malfunction without setting a DTC	Climate control DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Poor or loose connections at the terminals A/C signal circuit problem in the PCM (see A/C SIGNAL CIRCUIT TROUBLESHOOTING )
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 GENERAL TROUBLESHOOTING INFORMATION ) Powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Blown fuse No 20(7 5 A) in the under-hood fuse/relay box A/C system pressure is normal (see A/C PRESSURE SENSOR ) Poor or loose connections at the terminals
The A/C condenser fan and/or the radiator fan do not run with the A/C on	Probable cause 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 )	Climate control DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Blown fuse on the fan circuit Without SH-AWD, No 3-3 (SUB FAN) (30 A) With SH-AWD, No 3-2 (SUB FAN) (40 A) Poor ground at G301 (see LEFT ENGINE COMPARTMENT WIRE HARNESS (ENGINE COMPARTMENT BRANCH) ) Poor or loose connections at the terminals
The condenser/radiator fans do not run at high speed, but do run at low speed	Probable cause Malfunction in the fan high speed circuit(s) 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 )	Climate control DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Blown fuse on the fan circuit Without SH-AWD, No 3-3 (SUB FAN) (30 A) With SH-AWD, No 3-2 (SUB FAN) (40 A) No 3-5 (MAIN FAN) (30 A, Without SH-AWD), (40 A, With SH-AWD) 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	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 GENERAL TROUBLESHOOTING INFORMATION ) Navigation unit DTCs (see HOW TO CHECK ERROR HISTORY ) 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-HVAC display unit (without navigation) or the Audio-Navigation switch panel (with navigation) Do the audio communication line circuit troubleshooting (see AUDIO COMMUNICATION LINE CIRCUIT TROUBLESHOOTING )	Climate control DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Audio-HVAC display failure 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 ECT 2 circuit performance problem (see DTC P2183: ECT SENSOR 2 CIRCUIT RANGE/PERFORMANCE PROBLEM )	Climate control DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Manual blower motor operation
The A/C compressor clutch cycles rapidly on and off	Probable cause 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 GENERAL TROUBLESHOOTING INFORMATION ) 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
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, or the compressor clutch is mechanically jammed Do the A/C compressor clutch circuit troubleshooting (see A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING ), and repair any circuit problems If the A/C compressor clutch circuit is OK, then do the A/C compressor clutch check (see A/C COMPRESSOR CLUTCH CHECK ), and repair any problems with the compressor clutch	The A/C compressor relief valve If it has vented refrigerant to the atmosphere, correct the problem with the compressor clutch or clutch circuit, then replace the relief valve (see A/C COMPRESSOR RELIEF VALVE REPLACEMENT )
The A/C compressor relief valve has vented refrigerant NOTE: This indicates the A/C system pressure was very high	Probable cause A high-side restriction, the A/C condenser/radiator fans are inoperative, or the A/C compressor clutch is not disengaging If the fans and compressor clutch operate normally, recover refrigerant (see RECEIVER/DRYER DESICCANT REPLACEMENT ), and check for restrictions If the compressor clutch will not disengage, troubleshoot the clutch circuit (see A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING ), and check for mechanical problems (see A/C COMPRESSOR CLUTCH CHECK ) If the fans are inoperative, troubleshoot the fan circuits (see RADIATOR AND A/C CONDENSER FAN LOW SPEED CIRCUIT TROUBLESHOOTING )	Powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION )
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 Check the operation of the air mix doors Driver's (see DRIVER'S AIR MIX CONTROL MOTOR TEST ) Passenger's (see PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT ) Check the blower motor unit for obstructions Check for air leaks around the ducts and vents	Climate control DTCs (see GENERAL TROUBLESHOOTING INFORMATION ) Damaged cylinder head gasket

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.