Hi I have a 2016 Honda Civic EXL from Canada. Its 67,000km and Automatic CVT. I've been having an issue with my AC blowing hot and cold randomly. I have so far done the following based on instructions from my AC Technician:
1. Changed the desiccant bag from the condenser. At this point the AC Technician noted that there was sweating on parts of the condenser but no current leaks. He recommended condenser be changed within 6 months if not immediately possible.
2. He noted that the A/C Compressor clutch was being activated and deactivated when turned on and off respectively.
3. He noted that there were no leaks in the A/C lines as well as he pressure tested the system.
4. He recommended changing the A/C climate control module before attempting to change compressor, condenser and seals as it would be a cheaper fix and its possible that the module was not activating or regulating the temperature properly. As such he said it was possible it was not telling the compressor to send cold air when it should (when i turn down the temp). The AC control module was bought and changed but still have hot and cold temps blowing randomly. The part number was found from Honda Parts Catalog and replaced with: 79610-TBC-A51
5. I can say however that I notice that once the air gets warm from the vents and I start to press the gas pedal harder and go faster, it quickly switches back to cold air and stays for a while until it heats up again and I have to repeat these steps. I also notice that sometimes, there is a weird smell coming from the AC vents when the AC is turned on and a small hiss when just turned on. Trying to give as much information as possible so you know what I have tried so far.
6. I've also checked all relays and fuses relating to the AC and they are all fine.
7. There is a whirring noise that does come up sometimes. It sounds like its coming from the general region of the compressor but I honestly cant be too sure. I hear it even when in the car. It is an intermittent whirrr every couple seconds and other times it goes away.
My questions are:
a. Is it possible that this is an electrical problem concerning signals from AC control module to the compressor?
b. Since I have changed the AC control module for a brand new one - should I then assume its the compressor and condenser and have these changed? If not - what are my next possible steps?
c. Is it ok to purchase a remanufactured compressor kit with a new condenser?
d. I'm hoping someone can guide me for next steps as I'm truly fed up now of this issue and my Honda Dealer in my area says they are out of R1234yf gas so they are not accepting the car to test it and provide feedback.
HELPPPPPPPPPPPPP!!!!!!!!!
a. Is it possible that this is an electrical problem concerning signals from AC control module to the compressor?
Yes, of course. It's all computer controlled. A professional bidirectional scan tool would be needed for diagnosis.
b. Since I have changed the AC control module for a brand new one - should I then assume its the compressor and condenser and have these changed?
Never assume anything. Once again, you need a good enough scan tool to see what's going on with the electronics. This should have been done before replacing the module rather than guessing.
c. Is it ok to purchase a remanufactured compressor kit with a new condenser?
Rebuilt compressors are frequently junk. You'd be better off with a brand new one if the compressor needs to be replaced. More diagnosis is needed to make that determination.
Be aware that if the compressor is bad the condenser (as you've listed), the drier, and the expansion valve need to be replaced and the rest of the system flushed out since a worn compressor tends to contaminate the AC system with metal debris. (The expansion valve should keep debris out of the evaporator, but if that part is easily accessible it's not a bad idea to replace that as well to be on the safe side.)
d. I'm hoping someone can guide me for next steps as I'm truly fed up now of this issue and my Honda Dealer in my area says they are out of R1234yf gas so they are not accepting the car to test it and provide feedback.
You need to stop wasting time and money at the dealer and find a good local AC technician (NOT a chain shop) who knows what they're doing and can do a proper diagnosis of the HVAC system. The symptom you describe can even be caused by a hinky temperature blend door.
Hi @chucktobias! Thanks for responding. So I did scan the car but I did not get any readings from the AC module to be honest. Used a LAUNCH scanner. I will reattempt a scan. Any ideas what I should be looking for exactly?
You're not necessarily looking for codes. Codes are just the bare beginnings of the diagnostic process and depending on the scanner it may not be able to even read the HVAC system. What you need is to test the modules and other components of the HVAC system with a bidirectional scan tool to see how they respond and what data is available from sensors so you can get an idea of what's going on inside the system. On the mechanical side you need a manifold gauge set to monitor system pressures.