I have a 2009 Fit Sport I take short road trips in fairly often. After about two hours of driving the A/C stops cooling almost completely. I have to stop and let the car rest for 20-30 minutes before it starts working again.

I brought it back to the dealership to have it looked at and the system checked out okay. They then drove the car for only about hour or so and couldn't reproduce the problem so they couldn't do anything more for me.

Has anyone experienced this? Any suggestions on how to approach the dealership with this issue? I'd like to get this resolved before my warranty expires.

TIA!

 

They need to do a proper diagnosis, not just drive it around. This involves connecting pressure gauges and running a specific Honda test for A/C performance.

More than likely it's low on refrigerant and this test would show that.

Here's a link to the shop manual describing the tests.

 

Make sure youre reciculating and not fresh air, make suyre the drain out the bottom of the fit is working.

 

Fresh air is fine. The thing should not ice up under any conditions.

 

I have the exact same problem with my '09 Fit. This summer I went on a 700 mi. trip, and the AC gradually stopped cooling over a period of time. The weather in Florida was horribly hot, right at 100 F and prob 80%+ humidity. When I stopped to check at a rest area, the line leading toward the evaporator was totally ice-berged over with way too much ice. I pulled the cabin filter and cleaned out some debris, but this didn't make any difference. I waited 15-20 mins for the ice to melt off, then got going again.

I ran the fan only for 10-15 mins at highway speed, even turned the heat on to make sure any ice was gone. Switched the compressor back on, and it blew nice and cold again, working fine. But this would only last for maybe an hour or so, then gradually the airflow from the vents became less, and warmer temp, until it just wasn't getting much cool at all. Repeat the same way, compressor off, let ice thaw away 15-20 mins fan only, cool OK again.

No evidence of leaking refrigerant, no oily residue, condenser clear of any blockage.

After the trip I contacted a Honda service rep. He ID'd the problem as trouble with the evaporator temp sensor, check and replace if req'd. Gonna have them look at it next time I'm in for a service.

 

Hey bro, I also had this happen to me in my '07 GD3 on a 7 hour trip to San Diego. An hour into the trip, the A/C fan seemed to stop blowing. Thinking it was a fuse, I pulled over to check. Hmm, fuses looked good. Jumped back into the Fit, and the A/C started working again.
An hour or so later, it happened again. I pulled into a gas station, and checked for any sign as to the cause, still no obvious clue. Once again, when I started the car back up, the A/C was working just fine!
Like clockwork, the A/C quit a 3rd time. This time, I pulled the cabin filter out. It looked pretty dirty, so I tapped out as much debris as I could, then reinstalled it. That seemed to solve the problem, as it continued to work through the rest of the trip.
When I got back home, I changed to a new cabin filter. I haven't had an issue since.

 

Continuously adding outside air to the a/c load will indeed overload your a/c if the outside air is hot enough and humid enough. And that can lead to ice formation when there's too much water to get out of the air or when the drain is clogged, tho not plugged up. a/c is not an unlimited device; at least one you can afford.
Try puttimg your a/c on recirculation and see.
PS it can also occur if refrigerant is low.

 

I was under the impression that recirc was worse for icing because you are cooling cold air and pushing it closer to the point of freezing.

 

I'm going to have the level checked. If thats OK, I may try the resistor modification from another post. Sounds like the problem is really the temp sensor is tuned to cause thly comp. to cycle earlier at higher temps to help fuel economy. Adjusting the sensor redistance is artificially telling the ECU to cool longer to a lower temp before cycling.

I never have any issues on short drives around town in stop n go traffic. Also cooler ambient temps/humidity are less prone to cause probs I guess. I always keep it on Recirc, fan 2 or 3.

 

A/C is a closed cycle device. It will cool forever as long as the engine is running and there are no leaks.

If it's icing up, something is wrong; doesn't matter if it's on recirculate or fresh air. You can't "overload it."

I'd put the possible causes in the following order:
1. low refrigerant. It's counter intuitive, but if the refrigerant is low, areas of the evaporator will be extra cold and ice up, eventually spreading to the whole evaporator. It may have had insufficient refrigerant added at the factory and didn't manifest until extra hot, humid days this summer.
2. if the refrigerant is adequate, the electronic temperature sensor imbedded in the evaporator that causes cycling of the compressor may be faulty causing a too-cold condition.
3. the expansion valve may be faulty.

Running it on fresh air does not make the list.

A/C in good working order will not ice-up regardless of the humidity or ambient temperature.

It is true, the A/C may not be able to cool the cabin adequately on fresh air. This is simply a function of cooling and dehumidifying hot, humid outside air versus air that's already been cooled and dried (recirculated).

 

Performing the resistor mod (adding parallel resistors to the temperature sensor) will make icing-up worse. This in effect tells the ECU that the evaporator is warmer than the sensor itself registers, and runs the compressor more. The mod is intended to get more cooling from the A/C, but at the risk of icing up.

 

Icing is a problem caused by running the evaporator at a temperature too close to 0C or 32F degrees. The temp is measured by a thermistor in the evaporator sensed by the computer which switches the compressor off and on as necessary to prevent freezing.

Recirculate and outside air do not directly relate to the control of the evaporator temperature. Outside air may be warmer and prevent the system from reaching thermistor cutoff point but that is covering up the problem rather than fixing it. Freezing will never occur in a properly operating AC system regardless of whether it is using outside or recirculated air.

 

The thermister only measures the temp of incoming air; the warmer it is, the more the compressor runs. The longer the compressor pushes freon thru the cooler the more likely the cooler will collect ice if the incoming air is humid.
The trick is to reduce the load on the a/c by having intake ait closer to the setpoint of desired air temperature.
Its a common problem in humid atmospheres and going on recirculation reduces the amount of water that condenses from the intake air and reduces the a/c compressor load or cycles. Reducing the freon to the cooler reduces the potential for icing the condensate, especially if the drain is clogged. If the the condensate doesn't drain away quickly it will ice no matter what the a/c is doing so make sure the condensate drains away quickly. .
Reducing the a/c load increases mpg too,. Try running on recirculation; it doesn't completely shut off fresh air intake, just minimizes it at the lowest safe level.
We have to offer that advice a lot and it always works. try it, you'll like it.

Trying to better describe the situation I use the cooler rather than evaporator tho thats what it is, for the heat exchanger in the air stream supplied to the interior; another heat exchanger also acts as a heater when engine coolant is circulated thru it. In a/c mode it is more likely to freeze the condensate doesn't drain fast enough from the coils. As the freon is evaporating it soaks that heat from the air stream, thus cooling it. Supplying more freon (yes I know about 13a etc but more freon is easy to say as the refrigerant.) is more likely to freeze the condensate, especially if it doesn't drain fast enough from the coils. clogged drains are common as well.

 

horseshit, mahout. you're generally right about stuff, but you need to go back to A/C school.

The thermistor (it's more of a thermal resistor, not transistor) measures evaporator temperature. It's imbedded in the evap. Yes, evap temp will be a function of incoming air temperature, but its purpose is to keep the evaporator from freezing.

A well functioning A/C is perfectly happy regardless of the incoming air-temp/humidity and will not ice-up. They do design the things to cool and dehumidify air, condition it, in other words, in all conditions.

 

Honda fixed the problem. They found that it was a bad relay.

Thanks for the help!

 

Lets see: the incoming air temp is measured and its function is to keep the evaporator from freezing; how does it do that? and what is 'freezing' ?
perhaps when the incoming air is so laden with water ... ie 90%+ humidity. Is that all conditions? If it cooled incoming air under all conditions it wouldn't need the temperature measurement would it.

PS i'm not always right but I get a pretty high score; thats about it.

 

When you recool recirc air there's less water to remove and less temperature drop needed so the a/c works less hard. When the incoming temp falls enough the a/c cuts off til it rises again.
Incoming humid air is loaded with water and is hot so more a/c is needed.
cheers.

 

AC temp drop is a constant, in my understanding of ac work. In a well functioning system its always about 30 degrees.

 

The heat load is the amount of cooling that must be done first to cool the incoming humid air to 32F then second the load required to condense the contained water to liquid. That also requires the 'coil' to drain efficiently, otherwise the coil surface is blinded by the water film. The refrigerant evaporates in the inside of the 'coils' which removes heat from the incoming air on the outside.. If the a/c diidn't 'turn off' when the air is cooled sufficiently it would continue to remove heat from the water on the coils and freeze the condensed water. That pretty well eliminates cooling the incoming air. Surprised that ice can be an insulator?
And yes the area of the evaporator coils must be sufficient to allow the cooling to occur before the air gets past the evaporator coils. Its a time vs velocity vs heat transfer calculation.
PS water is an insulatort when the heat transfer rate thru water is less than the heat transer across the walls of the 'coils', which are often copper or aluminum. Try heating an empty aluminum frying pan compared to heating one filled with water. See which upper surface gets hotter faster. don't hurt yourself.

 

what relay did they replace? my 2009 fit does the same thing. it sucks.