My '07 USDM's A/C is freezing up (ice on evaporator coil and refrigerant return line). This only happens on long drives. It is currently at the stealership (extended warranty). Of course the dealer "cannot duplicate the problem" and has called Honda for advice. They have evacuated and recharged the system to rid the system of moisture (factory refrigerant charge). I believe the A/C's low pressure switch is defective. Has anyone had this problem and if so how was it repaired?

 

Subscribed for interest.

I'd also think the switch is defective and needs replacement. Try to have the condenser/drier looked at too - it's been integrated into one unit on our cars.

 

Update: The dealer service wanted $115 for the refrigerant change. I have a Honda extended warranty so I balked at this. The refrigerant change was Honda's idea not mine. They said since no parts were replaced the extended warranty didn't apply. I went to the stealerships general manager and explained my position to him. He said Honda would cover the $115 and they kept my car for further investigation and to get Honda's service rep involved. Luckily I took pictures of ice on the low pressure lines under the hood and of my thermometer showing cooled air temperature of approx 27*F. More to come I'm sure.

 

My first guess would be #18 on this parts list. If I understand correctly it measures the air temp coming out of the evaporator to determine how much to cycle the compressor.

majestic honda parts list, 07 fit sport, heater unit

Actually I want to experiment with that part, see if I can get my dash temp under 50F and the compressor to cycle less often than a complete on-off-on in 15 seconds with the fan speed on 1.

 

I agree, I've told them that. They're pure idiots there.

 

After my chat with the dealers general manager and getting Honda engineering involved, the dealer also decided that this part was the problem. Now the only problem is that this part is on national backorder.

 

Before this problem, my A/C dash temperature was always below 50*F at all fan speeds (of course it was lower at lower fan speeds). It swings between 40*F and 45*F with compressor cycles.

 

This is funny as heck. I've never had an AC system apart, never had auto repair training, don't have a degree, and at first glance I was still light years ahead of these techs.

I swear I should work for honda and make 3x the money I do now.

I guess I shouldn't break that part when experimenting, huh

 

Just to add,they did all this trying to save a part that retails for $17.75, and an hour labor at most to change. I just hope that they put oil back in after changing the refrigerant.

 

I can see why they didn't want to change it. If I read this manual right the AC has to be discharged, the blower unit removed, the pipes disconnected from the evaporator, and the evap side panel pulled off to remove the clip on the sensor that's connected to the evaporator. Yuk. They could have done that better- the other end of the retainer is in such an easy spot to get to.

 

Incorrect. It is a simple plug and play replacement. (You can see the sensor on the drivers side bottom of the HVAC housing.) My Fit was at the dealer for less than three hours for the replacement.

 

I'd like to know how they unclipped it from the evaporator core. (seriously, just in case I ever need to replace the thing.)

 

What fixed the problem?
Was it the A/C thrmistor?
My Son's '06 Civic is doing the same thing.

 

My 2012 freezes up when I leave the thermostat at about half way and go down from position 3 to 1 or 2, on a long trip. Turn it off, run fan for 10-15 minutes and it works normal. I now leave the fan on 3 and change only the thermostat to a warmer setting.

 

There are lot's of potential causes and fixes for freezing A/C.

Low refrigerant is the leading cause, I think. Counter intuitive, but it makes sense if you picture the compressor running all the time to try to cool, and freezing starts, then spreads. shudder.

The temp sensor imbedded in the evaporator, high pressure sensor, expansion valve, are all possibilities.

My experience this year driving 12 hours to FL was freezing about 3 hours south of Atlanta. Air flow was reduced and cooling was almost non-existent. Turning it off to defrost, then back on helped for short periods.

Key Largo Honda replaced the high pressure sensor, clutch relay, and recharged it. The trip back it worked fine. Around town since returning it seems more effective.

 

Here is the story on evaporator freeze ups. It is caused by the evaporator running at 32 F. or below and moving medium or high humidity air through it. There are some normal operating conditions where the evaporator temperature might drop below 32 degrees so Honda installed a temperature sensing device in the evaporator to tell the AC compressor when to shut down to prevent freeze ups. That device can be a thermistor that varies resistance by temperature or in some years a simple temperature switch similar to a non-adjustable furnace thermostat.

So if I was experiencing freeze ups I would look at replacing the thermistor or the thermo-switch depending on the year of your FIT.

A temporary work around that will help is to run on recirculate. This cools the same interior air over and over reducing it's humidity on each pass. This reduces the total amount of moisture available to extracted from the that air. Running the fan on higher speeds increases the heat exchanged by the evaporator and reduces the possibility of running the evaporator all the way down to 32 F and below.

Again the real fix is to replace the thermistor or thermo-switch.

Note: An AC system that is low on refrigerant will tend to also run at lower temperatures. So a properly charged system is also advised.

 

been driving fits since 2007 (3 FitSports). no issue for me.

 

My 2009 Fit has had freeze-up issues since new in the high humidity Midwest. It would take about an hour of highway driving to completely freeze up and be blocked.

I borrowed some a/c manifold gauges and found that the high side psi was 45 psi below spec at 2500 rpm. About $1.50 worth of refrigerant later, performance a/c seems instantly improved. It will take another summer road trip to prove out the freeze-up issue is resolved. I highly suspect some cars left the factory with barely adequate refrigerant.

 

That is a typical symptom of an undercharged system. You want the temp to never go below 39 or 40 degrees F. Go to Walmart in the housewares section and buy a digital meat thermometer. They are around $10. Stick it the center air vent and watch the it occasionally as you drive. In no condition should is ever go below 39 or 40. If it does, add a LITTLE R-134. If you add too much the MINIMUM evaporator temp will go higher and you will be complaining about poor cooling performance. All we are trying to do here to prevent freeze up is set the minimum temp that the evaporator can ever run at under any condition.

Be very careful not to over charge the system. You may have already put in enough R-134 to fix your problem.

I have seen several Honda Fits with a low R-134 that have your same symptoms.