2011 AC Air Conditioner shuts off when outside air temp is above 94 Degrees

[NYCSHO]

2011 SHO

Had this problem develop last Sept and now with the first hot day the AC Air Conditioner intermediately shuts off when outside air temp is above 94 F Degrees. Doesn.t seem to matter if the car is moving, idle, highway etc the only factor is the outside temperature. When the temperature is below 94 the AC runs fine and blows cold. There are no codes being thrown. The mechanic used a pro scanner last Sept and couldn't find anything when he ran the diagnostics in the scanner. Does anyone have any idea where to start as the HOT weather will be here shortly?

THANKS ALL

 

[SHOdded]

Possibly an issue with the ambient temp or cabin temp sensor? You can try cleaning the vents for the cabin temp sensor see if it makes a difference. I guess refrigerant levels are ok, with no leaks, since your mechanic would have checked for that?

Do you have the climate control set to AUTO, or MANUAL? May want to run it on manual and see if makes a difference.

Check duty cycle on the fans too. May be cutting out.

 

[Johnbigdog]

When you say it cuts off? Splain a little better. When a/c turns off does the L.E.D. on the Front Control Interface modue or touchscreen change?Does airflow change or does the temp get HOT? Can you control the temp at all? What happens in dual mode? If you shut it off let it sit, does cooling come back?

I wonder if your evaporator is freezing? But it should do it at lower temps more than higher unless the evap temp sensor is biased.

Check your cabin air filter.

 

[NYCSHO]

When the outside air temp is above 94 deg it cuts off.
- The Front Control Interface does NOT change at all
-The airflow does not change but the air blows as if it is just blowing through the vent, that is the air no longer blows cold
- I can control the temperature but setting it to max or 60 or recirculate has no effect
- in dual mode, the same things happen
- if I shut it off, let it cool it will come back but if the ambient air temp is besides 94 then it will cut off again within minutes.

Cabin air filter- was changed- no effect

where are the ambient and cabin air sensors located?

What is the "duty Cycle"- Check duty cycle on the fans too. May be cutting out.??

 

[Johnbigdog]

If the fans were bad you would have poor cooling stationary and good A/C moving.

What happens when you turn it to full heat? Does it get hot?

When you turn off the car and come back to it with it workimg, is there a really big puddle under the car.. if the evaporator is freezing, you allow the car to sit. It thaws. Then start the car and it frezes again.

I forget if our compresors are variable displacemet or not... hmm. Can' say looking at the clutch will mean anything.

 

[NYCSHO]

If the fans were bad you would have poor cooling stationary and good A/C moving.

What happens when you turn it to full heat? Does it get hot?

When you turn off the car and come back to it with it workimg, is there a really big puddle under the car.. if the evaporator is freezing, you allow the car to sit. It thaws. Then start the car and it frezes again.

I forget if our compresors are variable displacemet or not... hmm. Can' say looking at the clutch will mean anything.

It does not matter if the car is moving or not so I guess I can eliminate the fan.
Will wait for next 90 plus day to test if the evaporator is freezing and then thawing.
The really weird thing is temp on the Front Control Interface is above 92 otherwise the system works fine.

i will check turning the full heat but didn't seem to have any heating problems this winter but will check.

 

[Johnbigdog]

The air through the plenum hits the evaporator first, then the heater core. To get cold air you bypass the heater core. You can usually hear a change in the air flow when switching from hot to cold. If you have poor flow in heat and cool there is a restriction somewhere. A block of ice is a good restriction.

In the winter the compressor will only come on at about 32 and above.

 

[Jeff2017]

I had this issue with out 2008 Volvo V70. It turned out that the water pump was going bad and there play in bearings which reduced the belt tension. So the belt wasn't turning the compressor fast enough to work well on the hot days. On days in 80s it seemed to work. Took a while to figure because the water pump was not making any noise or leaking at that point.

 

[NYCSHO]

2011 SHO

Had this problem develop last Sept and now with the first hot day the AC Air Conditioner intermediately shuts off when outside air temp is above 94 F Degrees. Doesn.t seem to matter if the car is moving, idle, highway etc the only factor is the outside temperature. When the temperature is below 94 the AC runs fine and blows cold. There are no codes being thrown. The mechanic used a pro scanner last Sept and couldn't find anything when he ran the diagnostics in the scanner. Does anyone have any idea where to start as the HOT weather will be here shortly?

THANKS ALL

Turned out that system had too much refrigerant and when pressure built up due to the heat it shut the AC

 

[shaker281]

Thanks for the follow up solution. Good to know.
Assuming someone added refrigerant and did not check both high and low side pressures?

 

[tech10002]

That’s the danger with all these AC Pro type kits floating around that just hook to the suction.

It’s understandable when it happens with amateurs, but it’s a sad state when a professional mechanic just hooks a scan tool up and can’t bother to hook up gauges. Seems there are more and more that can’t fix anything unless there’s a code. I had to fix my moms 2 year old, under warranty Kia that was sticking at WOT. Dealer couldn’t fix it because there wasn’t a code. It ended up being the throttle butterfly shaft was galled. Five cents worth of sand cloth, and it’s been fine for 8 years. Had similar issues more times than I can remember on other cars where the dealer said there are no codes so we can’t do anything. Really?

 

[Johnbigdog]

That’s the danger with all these AC Pro type kits floating around that just hook to the suction.

It’s understandable when it happens with amateurs, but it’s a sad state when a professional mechanic just hooks a scan tool up and can’t bother to hook up gauges. Seems there are more and more that can’t fix anything unless there’s a code. I had to fix my moms 2 year old, under warranty Kia that was sticking at WOT. Dealer couldn’t fix it because there wasn’t a code. It ended up being the throttle butterfly shaft was galled. Five cents worth of sand cloth, and it’s been fine for 8 years. Had similar issues more times than I can remember on other cars where the dealer said there are no codes so we can’t do anything. Really?

There is a lot pain here. From a tech, to a customer, to cooperate. So many angles, a lot of learning, lots of pain.